Monday, October 01, 2007

NHS Choices Spreads Confusion About Allergy and Intolerance Tests

Question mark and reminders
Journalists and and a certain class of nutritionists frequently conflate allergy and intolerance. UK newspapers regularly carry stories about 'food allergies' where the topic is actually food intolerance and it is not unusual for IgG blood testing to be promoted as a scientifically and clinically validated test for the diagnosis of food allergies or intolerance. These misunderstandings are so common that I notice when a journalist doesn't make these mistakes.

Nonetheless, I was particularly irritated when a correspondent drew my attention to an NHS site with a section dedicated to allergies: Which allergy test? The page carries some useful information about various tests, both those which are available from the NHS and those that are direct-to-consumer. For some of the tests (e.g., the hydrogen breath test for lactose intolerance or the coeliac self-test) there is information about the specificity and sensitivity, as reflected in the number of accurate diagnoses, false positives or false negatives. Some of the descriptions even carry a warning that some tests are "[d]ismissed by allergists as unreliable and unscientific" (systematic kinesiology) or may be offered by people who "may not have relevant qualifications" (VEGA). The inclusion of such information for some tests and not for others makes it seem as if there are no comparable concerns for those tests where they are not mentioned rather than a lack of actual clinical data or research.

However, the credulous writer/s gave no such caveats about YorkTEST’s foodSCAN tests.
In this test, you send a small blood sample to YorkTest Laboratories. The lab examines your blood for IgG antibodies, which it believes cause food intolerance. Results are given in a traffic-light code: foods to avoid (red), to rotate (amber), and to eat freely (green).
Tests for: food intolerance.
Pros: the only intolerance test supported by Allergy UK. It is also supported by well-known figures such as Dr Hilary Jones and Patrick Holford.
Cons: very expensive (around £250).
However, when the well-respected clinician, Dr Glenis Scadding, Consultant Allergist at the Royal Nose, Ear and Throat Hospital gave her testimony to a House of Lords Committee that was considering allergy and allergic disease in the UK, she characterised IgG tests for food intolerance as a waste of money":
What I do dispute is that it is worth making any attempt to identify IgG antibodies. We all make IgG antibodies to food....I see no way in which this can be used to guide diet.

I don't think there's any point in spending money on IgG antibody tests. You're better off going to see a dietitian and using an exclusion diet followed by reintroduction. The IgG antibody tests are liable to leave patients on diets that are inadequate and patients often like to think they're improving. They carry on in the teeth of very little improvement and may end up malnourished.

I think [self-testing kits] should be banned.
The YorkTest foodSCAN range is available as direct to consumer tests; however, they are also frequently recommended by nutritionists who typically do not have any recognised or specific training in allergy diagnosis or management. It isn't clear why the people who put the NHS Choices Guide together did not take note of this strong criticism from an acknowledged expert when they noted allergists' criticism for other tests but chose to mention that the foodSCAN test is endorsed by well-known names without disclosing their relationship with YorkTest. Similarly, the Allergy UK Consumer Award is only based on anecdotal report and is no indication of clinical or scientific value. Allergy UK is admonished for their support of this testing in the House of Lords report.

In a comprehensive report HL 166-I (pdf from which pg numbers are given), the Committee makes a number of good recommendations and provide some useful summaries. Pages 86-88 cover the issue of direct-to-consumer tests such as the YorkTest foodSCAN IgG test for food intolerance and the YorkTest-Allergy UK MAST IgE test for allergies to food and airborne allergens, amongst others.

The House of Lords summed up their advice as follows (pg 87):
We are concerned both that the results of allergy self testing kits available to the public are being interpreted without the advice of appropriately trained healthcare personnel, and that the IgG food antibody test is being used to diagnose food intolerance in the absence of stringent scientific evidence...We urge general practitioners, pharmacists and charities not to endorse the use of these products until conclusive proof of their efficacy has been established.

It almost seems gratuitous to add that the House of Lords aligns themselves with clinical experts in their notion of who is qualified to diagnose allergies and allergic disease (hint, it is not the typical holder of a Diploma ION nor an auto-didact nor self-proclaimed expert nor celebrity nutritionists).

It is absolutely clear that the House of Lords has considered the evidence and finds that there is no adequate scientific or clinical support for the usefulness of these blood tests as a direct to consumer item; further than that, there is clear cause for concern as to the relevance of the tests. The House of Lords urges professionals in positions of responsibility and authority, whose opinions or recommendations may influence others, to refrain from endorsing this technique. NHS Choices includes cautions about other tests and techniques, it should include them about the YorkTest foodSCAN range and IgG testing for food intolerance.

People trust sources of information that come with the implicit imprimatur of the NHS. The information about the allergy tests is shoddily researched and rather confusing. NHS Choices should rethink their guide. They need to amend the text about IgG food intolerance tests and some direct to consumer allergy and intolerance tests to reflect the well-founded concerns expressed in the report from the House of Lords.

Related reading:

Science Lessons takes a lively look at kinesiology for food intolerance testing
Patrick Holford, IgG Testing and the House of Lords
Patrick Holford and His "Deeply Impressive" Scientific Proof
Patrick Holford Endorses Allergy/Intolerance Blood Test: The House of Lords Wants Responsbile Professionals To Cease Endorsement of Such Techniques
Food intolerance testing and migraine
Truthiness and referenciness make the case for IgG food intolerance tests
More allergy and intolerance testing nonsense: part 1
More allergy and intolerance testing nonsense: part 2
Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science
What is the Significance of IgG Antibodies and Testing?
Why IgG Testing for Food Intolerance Is Not As Simple As ABC or Doh Ray Mi

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Monday, May 14, 2007

Oil Seed Rape, Fashionable Demon or Time to Break Out the Pitchforks and Torches?


Judging by recent stories about oilseed rape, it is either the latest victim of fashionable demonology (wheat, gluten, dairy) or it is justly reviled and past time for the allergy-bedevilled villagers to take up the pitchforks and torches.

Against a backdrop on an increase incidence of hayfever in the UK, it is a little dispiriting that the stories contain a strong whiff of superstition alongside the science. Two representative accounts are, The rape of spring: Health concerns over crop (Independent) and Teacher forced out by oil seed rape (This Is London).

Oilseed rape is highly visible, its vast gharish swathes do not blend gracefully into the usual british landscape of colours: its vibrant coloration catches the eye, its cloying scent seems to swamp all others. If you're looking for an obvious scapegoat for crimes against your nose, eyes and upper-airways, then oilseed rape couldn't be a more noticeable culprit. If this were a detective story, then oilseed rape would be discovered at the crime scene, looking self-consciously guilty, fingerprints and DNA strewn about the scene along with incriminating documents that provide evidence of motive.

The article in This Is London describes the plight of Peter Hallam who is forced to flee from his home to the refuge of a hotel, 45 miles away because of his "severe allergic reaction to the oil seed rape fields surrounding his house". Except, it is not at all clear that Peter Hallam is allergic to oilseed rape. It seems that the diagnosis of allergy is based upon Hallam's personal conviction (Dr. Ben Goldacre recently commented on the unreliability of intuition):
The doctor couldn't know for sure what was causing it but I'm certain.
Based on his personal certainty, Hallam and his partner call for research and a general alert, "the general public should be made aware of the danger of these oil seed rape".

However, there is no indication that oilseed rape is more dangerous than any other plant. According to a BMJ commentary on the research, there is no clear evidence that oil seed rape affects health adversely:
the [MRC] report shows that there is evidence of health effects associated with the cultivation of oilseed rape but no convincing evidence that rape is a cause of widespread disease or ill health in the general population...

Only in Britain has oilseed rape been suspected by the public of causing ill health effects. In other rape growing countries, such as France, Germany, Denmark, and Canada, no such public concern against oilseed rape exists.
The Independent reports the opinion of prominent scientists. Professor Pamela Ewan, consultant allergist at Addenbrookes Hospital, said:
The amount of allergy to rapeseed is very low. People think they are allergic to it because of its bright colour and powerful smell when they are really allergic to other pollens that they can't see. There could be some adverse reaction to the volatile chemicals the plant produces. But I think the perception is much greater than the reality. Grass pollen is by far the most potent cause of hayfever in Britain.
There is a strong case for requesting a referral to a clinical allergist if you suspect an allergy to oil seed rape. A clinical allergist will be able to distinguish a reaction to oilseed rape from allergy to grass pollen. In combination with a thorough clinical history, a negative allergy test can liberate someone from the expense and inconvenience of unnecessary allergen avoidance. If there is allergy, then the allergist can provide guidance on the most appropriate and effective avoidance techniques and medication.

A clinical allergist can also advise somebody on whether there is evidence that indicates that they do not have a clinical response to a specific allergen (e.g., oil seed rape) but exhibit symptoms when they are exposed to that allergen along with additional allergens at the same time. If somebody does exhibit a reaction threshold, then an allergist can give advice on whether it is possible to reduce the allergen load by avoiding one or more of the allergens to which they are sensitised (it may not be the most obvious one). If selective avoidance is practical then it might be possible both to reduce symptoms and the need for pharmacotherapy.

The Independent piece acknowledges that:
[o]thers take a less rigorous approach to the science, preferring to emphasise sufferers' reported experience. Muriel Simmons, spokeswoman for the charity Allergy UK, said: "Rapeseed very rarely triggers an allergic response, but it may be an irritant"...

"I think it is worrying that we are seeing the yellow tide advancing and the number of fields turned over to rapeseed spreading. Whether it is affecting the immune system or not is irrelevant - it is making a lot of people feel very uncomfortable."
It is difficult to argue the case for funding further research into oilseed rape if there are strong indications that the prejudice against it may be unfounded. This reported attitude is rather more indicative of the pitchforks and torches approach than the scientific approach that one might expect from somebody representing "the leading medical charity for people with allergy".

Oh misery me! mecum omnes plangite!

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Wednesday, April 25, 2007

What Does Allergy UK's Consumer Award for Products Mean?

Art illusions, anaphora etc.
When Muriel Simmons joined Allergy UK she reorganised its finances and introduced a successful endorsement scheme.
The charity realised that an endorsement scheme would benefit three different groups. Firstly, it would provide a vital service to the public; secondly, it would revitalise their own turnover; and thirdly, with one in three members of the population suffering an allergy, an endorsement would supply an obvious marketing tool for manufacturers.

"I felt it would be a service to the public with allergies to say that we had tested the product and found that the criteria laid down by the experts (which were incredibly high) had been met." - Muriel Simmons

The idea evolved from the fact that sufferers were frequently contacting Allergy UK for advice on consumer decisions. They wanted to know which vacuum cleaners, cleaning products etc were most suitable, and Allergy UK realised they could turn this to their advantage...

Some companies had approached Allergy UK about endorsements in the past, without seeing why they should have to pay. But the charity could not risk endorsing a product without scientific evidence, and they could not ask specialists to give their time free of charge to review commercial products. The process had to be treated in a commercial way.
It is difficult for consumers to research appropriate accreditations etc. for testing services or the technical specification and efficacy of various products, so this is a useful service. Manufacturers who have purchased endorsements use them to support their marketing activities. Consumers are confident in their purchases because the products are endorsed by an appropriate body of experts.

YorkTest is endorsed by a number of YorkTest-styled experts; it also holds an Allergy UK Consumer Award that is frequently mentioned in publicity about the foodSCAN tests and MAST panel (multi allergen screening test). Understandably, the nature of the endorsement tends to be blurred when journalists or others discuss the tests and it tends to be shorthanded as a recommendation:
Only antibody tests that use blood like the YORK(tm) test are recommended by Allergy UK.
The Allergy UK (AUK) Seal of Approval has particular criteria; it is awarded to products that:
specifically restrict or remove high levels of named allergens from the environment of allergy sufferers and can be scientifically tested with measurable results.
Those criteria are established in a known research laboratory or are validated from published studies. What criteria need to be met for the Consumer Award?
The Consumer Award is intended for products that will generally benefit allergy sufferers and improve their state of health and wellbeing. The award is given entirely on the basis of consumer opinion, and evidence of this must be supplied from a minimum of 25 consumers. Their opinions can cover anything from durability and ease of use right through to value for money and perceived benefit. This evidence and a product sample will also be carefully assessed by a panel of experts from Allergy UK to verify the consumer's opinions. [Emphasis added.]
Elsewhere, I've seen explanations that the Consumer Award is what manufacturers purchase when they can't afford the testing for the Seal of Approval or they are too small to be able to afford clinical trials. The Consumer Award is for:
products that are of benefit to the public but which do not actually reduce or remove allergens in the environment and cannot be tested scientifically. Alternatively, the company concerned may not be able to afford clinical trials. In these cases Allergy UK can confer the Consumer Award which relies on anecdotal rather than clinical evidence.
I find this a little surprising given the frequency with which remarks that claim clinical validation are attributed to people associated with Allergy UK. E.g., in a Daily Mail item about allergy and intolerance tests, when discussing the foodSCAN intolerance tests:
Maureen Jenkins from Allergy UK says: 'This is a clinically proven test which means it has gone through scientific trials to show that it achieves the same result everytime and can be useful in diagnosing certain food intolerances'.
However, that story is from 2002, before even the publication of the much-cited GUT paper from 2004. If the reference is to unpublished scientific trials that had not been submitted to peer review, then this should have been made clear in the article. I am not aware of any published trial that shows that the foodSCAN tests achieve "the same result everytime and can be useful in diagnosing cetain food intolerances": and, as the reference is to "trials" I would have to have missed several or at least two.

I have examined the published literature, and I think that it is premature (at best) and possibily misleading to advocate IgG testing for the diagnosis of food intolerances. I don't believe that IgG for food intolerances has been clinically proven and I don't believe that there is sufficient basic science research to support the theory as yet. Ironically, I would agree that it would be currently inappropriate to seek a Seal of Approval for the foodSCAN tests or MAST panel even if they were eligible. But, I do think that it would be helpful if the claim that these tests are "clinically proven" were to be dropped. It would be helpful if there were a greater awareness that the Allergy UK Consumer Award is indicative only of anecdotal evidence, supplied by 25 consumers and verified by unindentified members of the original panel who made the award and those who have subsequently endorsed its renewal.

Judging by the audits of YorkTest's customer satisfaction questionnaires, I have no doubt that AUK and YorkTest could provide thousands of glowing customer testimonials. Similarly, having looked into the matter, it is clear that the Consumer Award is not subject to the "incredibly high" testing criteria by experts to which Muriel Simmons referred in the NVCO piece to which I referred at the top.

However, it would be helpful to know what others thought the phrase, "as recommended by Allergy UK" implied about the tests or what they understood by "clinically proven". Did you think that such an award could be made on the basis of anecdotal evidence from a small number of consumers? Did you assume that the endorsement was (at least partly) based on a review of the clinical evidence by clinical allergists and immunologists or active researchers? Would it be useful to know who had endorsed the award and its renewal?

Related posts:

Why Results from an Allergy or Intolerance Test May Be Misleading: Part 1 and Part 2
Self-Testing for Allergy and Intolerance in the UK: Part 1
Truthiness and referenciness make the case for IgG food intolerance tests
More allergy and intolerance testing nonsense: part 1
More allergy and intolerance testing nonsense: part 2
Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science
What is the Significance of IgG Antibodies and Testing?
Why IgG Testing for Food Intolerance Is Not As Simple As ABC or Doh Ray Mi

Click on the image or visit Flickr for further information about the images. 1. IMG_2441, 2. IMG_2446

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Saturday, April 21, 2007

Why Results from an Allergy or Intolerance Test May Be Misleading: Part 2

Bronze sculpture of a figure with a migraine by Jose SacalYou might expect a clinical test to have results that would be the same in any laboratory where a sample was tested and to be reproducible, e.g., the same result when tested on a different day. Beyond this, according to Dr. Adrian Morris:
An Allergy Test should reliably identify one or more agents to which the patient reacts on each exposure. These allergens must be the cause of the patient’s immune-mediated allergic symptoms. This reaction need not necessarily be IgE mediated, but may involve a T-cell Delayed hypersensitivity reaction or direct Histamine release from Mast Cells and Basophils. The test should be reproducible and identify the implicated allergen on each occasion the test is done. The allergy should be specific to that allergen with minimal false positive test results (when the test is positive in someone with no allergy), or false negative test results (where the test is negative in a person who is known to be allergic to that allergen). Abnormal (Positive) results should always be associated with clinical allergic disease.
However, although some tests have a high degree of specificity and reproducibility, there are still notable caveats, particularly when testing for food allergens (I shall discuss these in a later post). There are also basic issues concerning the appropriate value and interpretation of diagnostic tests. According to the National Allergy Strategy Group's (NASG) report to the House of Lords Science and Technology Subcommittee that is reviewing allergy and allergic disease in the UK:
Most doctors do not know how to interpet these tests; thinking, incorrectly, that a positive equals an allergy diagnosis. Clinical research is necessary to throw light on this eg in nut allergy, a 'grey area' has been identified in the so called 'positive' range, where 50% of patients are allergic but 50% are tolerant (Clark & Ewan 2003). Another development is to identify the level in a test result above which nearly all patients have allergy (Sporik et al 2000; Hill et al 2000).
There is some concern about the misdiagnosis of allergy and inappropriate allergy or intolerance tests that can harm consumers. The NASG reports that:
Unorthodox and unsubstantiated practices including methods of diagnosis abound in the private sector...This is in part driven by absence of NHS allergy services. Many patients get the wrong diagnosis. This sometimes leads to medical harm; or financial problems for the patients; and wastes NHS funding-unproven private treatment is being paid for by some [Primary Care Trusts].

Even the established tests (specific IgE antibody)-without interpretation-can be misleading. Thus sales of these direct to the public eg supermarket, high street or through the media are harmful. Patients are diagnosed allergic when they are not and inappropriate management follows. Furthermore, there is a lack of quality control and tests in these laboratories can be positive when the same test in a [Clinical Pathology Accreditation (UK) Ltd] accredited laboratory is negative.
It might be useful if consumers had ready access to information about whether or not a testing laborary is CPA accredited or similar but it is rather difficult to find this information even on CPA's own website. Under these circumstances, it would have been helpful if the NASG had named the testing laboratories where such failures had occurred and the specific tests that are known to be problematic.

YorkTest is possibly the best known provider of direct-to-consumer allergy and intolerance tests in the UK; these tests have been endorsed by Allergy UK. However, what does YorkTest have to say about the accreditation for its foodSCAN tests? Well, by and large it doesn't. It tells us about its quality system accreditation: the sort of quality systems that are concerned with appropriate documentation of processes and procedures in most industries.
YORKTEST Quality System Accreditation

Certification to ISO9001:2000
Certification to ISO13485:2003
These accreditations are not related to the validation of the scientific testing and I don't understand why they were included in this section. ISO9001:2000 is a quality management standard and ISO13485:2003 is a medical device standard which sounds more relevant but is mostly about quality management and documentation.

However, Yorktest does give more specific information about foodSCAN:
YORKTEST foodSCAN Regulatory Compliance

Compliance with the European Medical Device Directive 93/42/EEC; for the manufacture of the sterile lancets

Compliance with the European In Vitro Diagnostic 98/79/EC; The blood collection device (for home use) and the reporting of results directly to the consumer in combination (but not including) the above Professional laboratory service, are covered by Annex III Section 6 of the IVD Directive. YORKTEST Laboratories fulfils the requirements of Annex III, Section 6 which include the Design Examination by the Notified Body (UL International).
I'm delighted to learn that YorkTest uses sterile lancets that comply with relevant directives but it might be more useful to know about this CPA lab accreditation that NASG considers to be of such great importance. Sadly, even the impressive sounding In Vitro Diagnostic 98/79/EC does not cover this. It seems that Annex III is about a self-certification process that involves some degree of examination by a 3rd party:
EC Declaration of Conformity. A procedure in which the manufacturer declares to conformity of his products with the IVDD. Applicable to all devices except those listed in Annex II or devices for performance evaluation. All "ordinary" IVD products can be CE-marked using this "self-certification" route. Additionally, for devices for self-testing, a Notified Body shall carry out an examination of the design.
According to the Medicines and Healthcare products Regulatory Agency the IVD Directive 98/79/EC: "covers the placing on the market and putting into service of In Vitro Diagnostic Medical Devices".

There are many standardised food extracts and aero-inhalants for IgE testing but not for food-specific IgG. Because of this, I had expected clearer information about laboratory accreditation or accreditation for YorkTest's IgE tests. However, the issue of accreditation is no clearer for the YorkTest multi-allergy screening test (MAST).
MAST Accreditation
The MAST testing service provided by YORKTEST is compliant with the European In Vitro Diagnostic Directive 98/79/EC; The blood collection system, transport of the sample and the reporting of results directly to the consumer in combination with the above Professional laboratory service, are covered by Annex III Section 6 of the IVD Directive. YORKTEST Laboratories fulfils the requirements of Annex III, Section 6 which include the Design Examination by the Notified Body (UL International).

Since November 2002, the Company has (successfully) been a member of the UK NEQAS (United Kingdom National External Quality Assessments Service for Immunology and Immunochemistry) scheme for measurement of food and inhalant specific IgE’s.
It seems as if CPA(UK)Ltd EQA accredits the UK NEQAS member schemes. It would be helpful if any relevant accreditation were to be clearly stated.

YorkTest made a statement to the House of Lords Subcommittee (pdf) and included a description of its accreditations that it presumably felt to be relevant but don't seem to be indicative of scientific validation.
YORKTEST is keen to differentiate itself from the non-scientifically validated service providers. YORKTEST holds three SMART awards from the DTi, both ISO9001:2000 and ISO13485:2003 Quality Management Certificates, and the Food Allergy and Food Intolerance Testing Services they offer are fully compliant with the European In Vitro Diagnostic Directive 98/79/EC Annex III, Section 6 (self-test) which includes the Design Examination by the Notified Body (UL International). YORKTEST also holds the Queen's Award for Enterprise: Innovation. Despite these accreditations YORKTEST often finds itself grouped with the less reputable organisations and still finds resistance from GPs or clinicians whose patients are interested in exploring YORKTEST further.
As listed in this document, none of these particular accreditations is indicative of scientific validation. A SMART award is the research and development grant scheme for small to medium sized businesses that used to be run by the Dept. of Trade and Industry: I've discussed the relevance of the other accreditations above. As detailed, YorkTest's accreditations do not distinguish it from other companies offering a similar direct-to-consumer IgE or IgG blood testing service. E.g., Cambridge Nutritional Sciences (CNS) lists ISO9001 quality systems as part of its "on-going commitment to customer service" and it uses CE marked items such as sterile lancets. It is entirely possible that CNS have the CPA accreditation that was mentioned by NASG but they neglect to state this explicitly.

Imutest offers allergy and intolerance tests direct-to-consumer. Imutest is currently under new management and there is no information about relevant accreditations on the website. This was a little disappointing as I have seen a previous claim about the clinical validation of Imutest's IgE testing that looked very interesting:
Imutest is a clinically proven IgE allergy test, just like those used in hospital laboratories. In a study of 200 patients referred to an NHS allergy clinic for allergy tests, Imutest correctly identified allergies present with an accuracy of 98% in comparison to the gold standard laboratory test method.
I searched Entrez PubMed but could not find a reference to Imutest and I haven't yet received a reply to my enquiry but I understand that there may be some administrative disarray at present.

I am unconvinced that there is scientific or clinical validation for IgG testing in the diagnosis of food intolerance (see related posts). I accept that IgE testing for some allergies is a well accepted and validated technique (albeit the results should be interpreted by an appropriate clinician and alongside a full clinical history) however I think that it would be helpful if the companies that offer this testing would detail their relevant laboratory accreditation or independent clinical validation of individual tests. In the absence of labs that are members of the same accreditation scheme, it is difficult for consumers to have confidence that the tests are reliably measuring what they are said to measure. Further, unless the laboratories are explicit about their measurement methods and how they convert the results into clinical significance, e.g., what distinguishes severe intolerance from a food that should be 'rotated' rather than eliminated, then this undermines standardisation/relevance of the results. The testing laboratories should be prepared to state their CPA (or similar) accreditation even for a well-understood technique such as the array of IgE tests for allergies: without it, consumers can not be confident that they are getting the quality of results that they are paying for.

Related posts:

Why Results from an Allergy or Intolerance Test May Be Misleading: Part 1
Self-Testing for Allergy and Intolerance in the UK: Part 1
Truthiness and referenciness make the case for IgG food intolerance tests
More allergy and intolerance testing nonsense: part 1
More allergy and intolerance testing nonsense: part 2
Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science
What is the Significance of IgG Antibodies and Testing?
Why IgG Testing for Food Intolerance Is Not As Simple As ABC or Doh Ray Mi

Click on the image or visit Flickr for more information about the image.

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Monday, March 19, 2007

Why Both Misdiagnosis or Inappropriate Allergy and Intolerance Tests Can Harm Children

Allergies
I have been writing a lot about allergy and intolerance tests recently; a number of factors have contributed to this. The House of Lords is currently scrutinising allergy and intolerance in the UK. When I look through the medical histories of the children with whom I work, in 60-80% of them, the parents have usually indicated that there are several allergies and intolerances. I would estimate that there is clinical confirmation of these allergies etc. in fewer than 2% of the children.

It is breathtakingly difficult to obtain a referral to a clinical allergist in the UK. In the whole of the UK, we have the equivalent of 26.5 consultant posts: approximately 5 of those are specialists in paediatric allergy. It is frequently argued that the lack of NHS allergy diagnosis and management pushes people who suspect that they have allergies towards the more dubious fringes of CAM or to testing laboratories that claim clinical validation and "sound science" for their product range of tests.

Both allergies and intolerances can have a dramatic and deletrious impact on quality of life. Allergy can kill. It is difficult to write about less severe forms of allergy because it is not practical to predict whether or not a mild allergy might suddenly become a life-threatening allergy.

A number of children 'grow out of' allergies. Some children have allergies that are multi-systemic and this puts them at particular risk. Allergies are typically managed, not cured. An exception to this is the laborious process of immunotherapy for some allergens which is rarely available on the NHS in the UK and is reserved for those people for whom medical management has failed.

Dr. Glenis Scadding is a consultant allergist with an fine reputation. She has clearly and elegantly stated that IgG tests for the diagnosis of food intolerance are "a waste of money". She has criticised the availability of direct-to-consumer IgE tests because they lead to "mis-diagnosis and mis-allergen avoidance". When she gave testimony to a recent House of Lords SubCommittee meeting she gave an excellent example.

(This recording of the SubCommittee meeting on 15 March 2007 is available from the archive for 28 days: thereafter, an authorised transcript will be available. I have used CM to indicate that the speaker is a member of the House of Lords' SubCommittee. Any punctuation, emphases or mistakes in the transcript are mine.)

Start transcript.

CM: Tell us what you think about self-testing kits and whether they should be-are they sufficiently-regulated?

Dr. Scadding: They should be banned.

[Laughter.]

Dr. Scadding: I'm very sorry...But...For example, I saw a child this morning before coming here and she had...We did skin tests that are well recognised and she had skin tests to house dust mite and also to tree pollens. Two kinds of tree pollen. She has absolutely no symptoms referable to the tree pollen whatsoever. She does not have Spring Hayfever. She has good symptoms related to the house dust mite, so I treated her with house dust mite avoidance and anti-allergy therapy.

If she had got a kit, then she would have felt that she was tree pollen allergic as
well and something had to happen about that. She has sensitisation but not clinical disease. And if you do a test, only about half the people with that positive test will have clinical disease.

So, you can not have self-testing kits: they're going to lead to mis-diagnosis, mis-allergen avoidance. You need both the test and a detailed history taken by somebody who has some experience of allergy history taking and interpretation of tests.

End transcript.

Dr. Scadding regularly sees children who have suffered clinical harm, e.g., unnecessary surgical procedures such as tonsillectomy, adenoid removal, the placement of grommets etc. when the real problem has been undiagnosed, and therefore untreated, allergy. Later in the meeting, Dr. Scadding answers a question about inappropriate treatment.

Transcript starts.

CM: Dr. Scadding, how often do you see patients whose treatment has been inappropriate? I'm not talking about the ones where the allergic allergen has been missed but where they've actually been treated inappropriately for their allergy and have therefore come to clinical harm before they're referred?

Dr. Scadding: At least once a week-and often more than that.

CM: And what are the main causes?

Dr. Scadding: The main causes are that they have been unrecognised or under-treated or treated for something other than allergy.

End transcript.

In addition to clinical harm, children who are mis-diagnosed with allergies or intolerances may follow a very restricted diet that might not provide all of the nutrients that they need and may lead to malnutrition. So, I apologise in advance, but I shall be covering the topic of allergy and allergic diseases in children for some time to come.

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Friday, March 16, 2007

Food Allergy and Intolerance Tests: YorkTest Gives Evidence to the House of Lords

A young boy and his dog in a position of prayer
And please let Shinga hear some decent testimony before she explodes.

Dr. Glenis Scadding is a consultant allergist with an fine reputation. She has clearly and elegantly stated that IgG tests for the diagnosis of food intolerance are "a waste of money". She has criticised the availability of direct-to-consumer IgE tests because they lead to "mis-diagnosis and mis-allergen avoidance".

However, at the same hearing where Dr. Scadding spoke, and earlier in the session, Dr. Hart, a representative of YorkTest, gave evidence at a meeting of the House of Lords, Science and Technology SubCommittee hearings that are investigating allergy and allergic disease in the UK.

In summary, Dr. Hart acknowledged that IgG levels are not necessarily related to either food intolerance or chronic conditions. She also explained that the testing criteria for food intolerance are not as standardised or as high quality as other clinical testing. One might question why it is worthwhile for consumers to spend money on a test that is not agreed to diagnose food intolerance and does not attain the same standard as other clinical tests.
The antibody, the presence of antibodies, and this, I believe is true for IgG and IgE, doesn't necessarily mean disease or no disease.

Unfortunately, in our business, it's not like measuring thyroid function tests, where you've got a beautiful, international reference preparation, all laboratories are controlled, we know exactly what we are measuring, we know the normal ranges. We haven't got the luxury of our higher order standards, the international reference preparations ...so that we, in putting a food down onto the plate, and we have got a wide range of fruits, vegetables and the key foods on the plate. That's what we use.
It can be difficult to understand oral evidence at specialist hearings. However, when the questions are simple it is irritating that an expert's evidence should be so muddled and difficult to follow. I shall comment on Dr. Hart's testimony in follow-up posts. For now, I thought that it might be helpful to post some more of the oral evidence in the House of Lords' investigation in allergy and allergic diseases.

This recording of the SubCommittee meeting on 15 March 2007 is available from the archive for 28 days: thereafter, an authorised transcript will be available. I have used CM to indicate that the speaker is a member of the House of Lords' SubCommittee. Any punctuation, emphases or mistakes in the transcript are mine.

Dr. Gill Hart is the Technical Director of YorkTest Laboratories. Mr. Dillon is the representative for NICE, the National Institute for Clinical Evidence.

Start transcript.

CM: Can you explain to me, as a lay person, how the IgG food allergy tests work given that people who are not allergic to specific foods can still produce an IgG antibody response when they eat those foods?

Dr. Hart: Yes, of course. I think when we consider the antibody response to an antigen challenge we need to really think that the antibody response is only the first part of the whole reaction. The antibody, the presence of antibodies, and this, I believe is true for IgG and IgE, doesn't necessarily mean disease or no disease.

What does make a difference is the complex cascade of events that occurs after that antibody has been raised. And what we find, that the IgG we use as a marker, that a reaction has occurred but that doesn't necessarily mean that the reaction has gone on to provide a cascade of results resulting in disease.

Now, we know that the mechanisms for this are unclear and as a company we have tried to support and collaborate with groups that find out more about these mechanisms. Indeed, we have provided tests to a leading London hospital who have now shown, and this evidence is going to be presented in Digestive Disease Week in Washington in May, that in inflammatory bowel disease, there is a significantly higher IgG titres than in normal groups and it is the first time this has been shown.

In addition, we've also shown, or the group has also shown independently but using our test, that people's reported food sensitivities, i.e., filling in a questionnaire, saying, "What am I sensitive to?", actually correlates very, very well with the IgG levels and this is particularly in ulcerative colitis. Very preliminary research and it's something that we really hope the team, at this London hospital will build on. We have struggled, working with others, to get grants to do this sort of work. But we really want to encourage the understanding of these mechanisms which we know are not yet clear.

CM: Could I ask you how often you find negative results?

Dr. Hart: Yes, of course. We actually provide a food intolerance indicator test. Bear in mind that the people who come to YorkTest have chronic conditions. They have...Our recent survey data, which we published, showed that over 70% of the people that come to YorkTest have suffered for more than three years with their condition. So, it isn't a normal population that comes to YorkTest. What we find is that between 75 and 80% of those people will have at least one positive scoring to one of our 113 foods.

CM: Perhaps I could ask the other members of the panel...I understand that the IgE antibody tests are an established part of NHS diagnostic routines, is there any evidence to support the use of IgG antibody food tests.

[Silence and confusion.]

CM: Mr Dillon?

Mr Dillon: I'm sorry. I've no information to enable me to answer the question. NICE hasn't looked at that particularly.

...

Dr. Hart: For me, to support the use of IgG tests? Yes, there have been independent clinical trials that have been carried out and published in, this one key one, which is a double-blind placebo controlled trial published in Gut in 2004 by Atkinson which was actually an independent study but used the YorkTest test. There has been a study, recently published, in Nutrition and Food Science. Another in Headache Care.

And indeed the recent study that has been carried out using the YorkTest test commissioned by Allergy UK and independently audited by the University of York, used with 5286 of our consumers has shown that people who rigorously adhere to our diet, 3 out of 4 of those people are showing some benefit to their chronic conditions. The considerable amount of data...and we know ourselves as a company that we don't do a lot of aggressive advertising, we can't do that, and the company's grown rapidly, mainly on word-of-mouth, because people are showing benefit and we see every day that people, there is, as we know, an unmet need and people are suffering and are then seeing benefit by using our service.

CM: Can I just be clear? That with these tests, you're measuring the amount of the molecules of IgG, you're not measuring specific IgG or IgE, are you?

Dr. Hart: We're measuring food-specific IgG in our IgG tests. So we have, so when you talk about...

CM: Sorry, when you say food-specific...what foods? Are you looking at specific...?

Dr. Hart: We are. We have a range of different services but the main one is 113 different foods. You can imagine on a ..The test we use is an ELISA test methodology. So you can imagine that a purified food preparation put onto one of our ELISA plates, is actually a mixture of proteins. Of course, wholemilk would be a mix of different proteins.

Unfortunately, in our business, it's not like measuring thyroid function tests, where you've got a beautiful, international reference preparation, all laboratories are controlled, we know exactly what we are measuring, we know the normal ranges. We haven't got the luxury of our higher order standards, the international reference preparations ...so that we, in putting a food down onto the plate, and we have got a wide range of fruits, vegetables and the key foods on the plate. That's what we use.

CM: I don't particularly want to concentrate on Dr. Hart all the time, I apologise to the others. You mention the report commissioned by Allergy UK, we've got a copy of it here. I wonder if you can tell us, has it been published? Has it been shown in a professional journal yet?

Dr. Hart: It has. It was published at the beginning of February in the Journal of Nutrition and Food Science.

CM: And you talk about chronic medical conditions but it's quite unspecific about these.

Dr. Hart: Yes, that's the interesting area really in terms of the type of people that come to YorkTest with chronic conditions. As you can see from the paper, it clearly outlines the different sort of conditions that people do come with and I think, because I understand that in the medical community, people are used to looking at specific conditions, it's very difficult to sometimes understand the concept that one or two different factors, like removing food from the diet, could actually benefit a range of conditions.

CM: I think that a lot of conditions will get better with a better diet won't they?

Dr. Hart: That's true.

CM: That is a concern.

Dr. Hart: That's true. But what we do find is that specific combinations of foods do actually show more benefit than removing the typical foods that you might imagine would be responsive to allergy. It's those particular combinations that we can identify using our test.

CM: I'm sorry to keep asking you...Do you ever find that there is such a wide range of IgG reactions when you do your test that the person who sent the kit in is almost on a starvation diet?

Dr. Hart: We're very, very aware of this. As you're probably aware we do provide a nutritionist service with our...nutritional consultation with our...service. We do very unusually find, well not very unusually, we do find people with sometimes which have a high level of reactivity; say, greater than 10 differents foods in our test. We treat these with extreme caution and we always talk to that particular customer and talk through about how they may want to prioritise. We'd never advise removing lots of different foods from one's diet-and that's very irresponsible-but we would suggest that they prioritise and maybe take some of the ones with a particularly high titre out from the diet first and see whether that benefits.

In the end, this is an aid to management of diet. It's a little route-map rather than going through the laborious trials of elimination diet which-elimination diet and challenge which-maybe you're never going to find the exact combination of foods that people are intolerant to. This is an aid to management of diet and a route-map through for the consumer to help them.

End transcript.

Related posts:
Food intolerance testing and migraine
Truthiness and referenciness make the case for IgG food intolerance tests
More allergy and intolerance testing nonsense: part 1
More allergy and intolerance testing nonsense: part 2
Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science
What is the Significance of IgG Antibodies and Testing?
Why IgG Testing for Food Intolerance Is Not As Simple As ABC or Doh Ray Mi

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Thursday, March 15, 2007

IgG Tests Are A Waste of Money: House of Lords Committee Hears Evidence, Let's Hope That They Listen

Bronze sculpture of a figure with a migraine by Jose SacalI think that IgG tests may accurately measure IgG levels but I do not believe that there is scientific support to confirm the relevance of IgG levels in the diagnosis of food intolerance. I have stated this in several posts over the last few weeks (see list at foot of post).

Today, the House of Lords SubCommittee that is looking into allergy and allergic diseases in the UK heard Dr. Glenis Scadding, Consultant Allergist of the Royal Nose, Throat and Ear Hospital, state this in a far more succinct and elegant fashion. My draft transcript of the full exchange from today's meeting (audio recording: available for 28 days and thereafter in transcript form) follows but the highlights from the redoubtable Dr. Glenis Scadding are:
What I do dispute is that it is worth making any attempt to identify IgG antibodies. We all make IgG antibodies to food....I see no way in which this can be used to guide diet.

I don't think there's any point in spending money on IgG antibody tests. You're better off going to see a dietitian and using an exclusion diet followed by reintroduction. The IgG antibody tests are liable to leave patients on diets that are inadequate and patients often like to think they're improving. They carry on in the teeth of very little improvement and may end up malnourished.

I think [self-testing kits] should be banned.
My draft transcript of the relevant part of today's committee meeting is as follows. I will amend this when a better recording is available or as an authorised transcript is available. I have identified the speakers where practical: CM indicates that a subcommittee member is speaking. Any mistakes or emphases in the transcript are mine.

Start transcript of oral session, 15 March 2007.

At around 1:23 the committee members discuss the YorkTest consumer satisfaction survey paper commissioned by Allergy UK and irritable bowel syndrome. Ms McManus of Allergy UK praises the value of the Hardman and Hart study and its implications for chronic illness.

Dr. Scadding: It's well known that irritable bowel syndrome can respond to dietary exclusion; I have no dispute with that. What I do dispute is that it is worth making any attempt to identify IgG antibodies. We all make IgG antibodies to food. Pam Ewan will tell you that 100% of the population she studies has IgG antibodies to egg and I see no way in which this can be used to guide diet.

In the Gut paper, which is the best paper produced, the sham group did not avoid dairy or wheat which are the two major problems with IBS patients and therefore it's not surprising that at the end of the survey there was a 10% difference. In that paper you needed, the number needed to treat was 9, whereas if you do an exclusion diet the number needed to treat is somewhere between 1 and 2.5.

So, I don't think there's any point in spending money on IgG antibody tests. You're better off going to see a dietitian and using an exclusion diet followed by reintroduction.

The IgG antibody tests are liable to leave patients on diets that are inadequate and patients often like to think they're improving. They carry on in the teeth of very little improvement and may end up malnourished.

CM: These [are] self-testing kits you're referring to.

Dr. Scadding: No. These are the York Laboratories' blood tests.

CM: Tell us what you think about self-testing kits and whether they should be-are they sufficiently-regulated?

Dr. Scadding: They should be banned.

[Laughter.]

Dr. Scadding: I'm very sorry...But...For example, I saw a child this morning before coming here and she had...We did skin tests that are well recognised and she had skin tests to house dust mite and also to tree pollens. Two kinds of tree pollen. She has absolutely no symptoms referable to the tree pollen whatsoever. She does not have Spring Hayfever. She has good symptoms related to the house dust mite, so I treated her with house dust mite avoidance and anti-allergy therapy.

If she had got a kit, then she would have felt that she was tree pollen allergic as
well and something had to happen about that. She has sensitisation but not clinical disease. And if you do a test, only about half the people with that positive test will have clinical disease.

So, you can not have self-testing kits: they're going to lead to mis-diagnosis, mis-allergen avoidance. You need both the test and a detailed history taken by somebody who has some experience of allergy history taking and interpretation of tests.

CM: But because the number of experts is so few and far between...It's inevitable

Dr. Scadding: Absolutely right...

CM: ...it's inevitable that you are going to be using tests.

Dr. Scadding: People are training-a lot of Primary Care nurses are being trained in doing skin prick tests and interpreting them, in places like the Respiratory Training Centre at The Athaneum in Warwick. And I think that may be a way forward.

CM: [Calling on Dr. Mills]

Dr. Mills: I'd just like to endorse what Glenis had said and I think actually for food allergy it's even worse. And that there are a lot of people who will have apparently been sensitised to foods like wheat but actually don't have any symptoms. And that can be really problematic when people eliminate important food groups from their diet.

CM?: What about the issue of inflammatory bowel disease that we heard about in the last evidence session.

Dr. Mills: What? You mean in terms of the IgG or the...

CM: Yes.

Dr. Mills: It's not particularly my area of expertise. But I think that it's a symptom and that people do benefit from dietary interventions. But the link at a molecular basis between IgG and irritable bowel syndrome is not apparent. And we make these antibodies to our food protein as part of our normal functioning.

CM: Ms McManus? This was a study that, if I'm right, your organisation commissioned. I just wondered if you had anything that you want to add to what's been said.

Ms McManus of Allergy UK: I think the main thing that I've got to say is as we were saying. You know... It's a lack of other places to send these people to. Err, we would give the YorkTest purely because it's the only one that has undergone trials-particularly for IBS and that's what we would say, that we would [be] happy to endorse it for, would be for those kind of symptoms. Eh, but, you know, we wouldn't recommend any other test.

End transcript.

I have to say that I am surprised to hear Ms McManus say that, as Muriel Simmons endorsement of YorkTest tests has been used considerably more liberally than solely in the promotion of IgG tests for IBS. I have said repeatedly that if Allergy UK limit their endorsement of YorkTest food intolerance tests to irritable bowel syndrome then they should state this unequivocally.

Allergy UK might consider whether it is premature at best to discuss the purported value of food intolerance testing in the treatment of chronic illnesses. They have said, repeatedly, that the people who contact them rely upon them for a good quality of advice and place their trust in them. It now seems as if some of the proxy trust that people have been asked to place on the value of IgG tests for food intolerance has been misplaced. Similarly, questions may need to be asked about Allergy UK's collaboration and endorsement of an IgE test (the YorkTest Allergy UK MAST (multi allergy screening test)) that does not mandate the involvement of a suitably qualified professional in the interpretation and implementation of the results.

If Allergy UK is truly recommending YorkTest faute de mieux and for want of anywhere else to make referrals then I have some suggestions:
  • coach the enquirer to advocate for themselves or someone else when approaching a GP
  • if a GP is unable/unwilling to make a referral to an NHS Allergy Clinic, then advise the enquirer to consider a private referral to a Clinical Allergy specialist. Even in London, for the cost of a YorkTest 113 foodSCAN test for intolerances, it is possible to purchase:
    • a consultation and tests at a well-regarded allergy clinic
    • a consultation with a leading consultant and researcher plus several tests
    • a consultation with a leading consultant and researcher, but tests would an additional cost
    • outside London, I would expect people might be able to have a consultation with an expert and comprehensive and relevant testing
  • several consultations with a dietitian (NB, appropriately qualified dietitian, not a nutritionist) who can guide and support the enquirer through an elimination diet.
If an enquirer suspects that they might have a mix of allergies and intolerances and requires both the YorkTest Allergy UK MAST (multi allergy screening test) and the 113 foodSCAN test, then the price comparison with the cost of seeing a relevantly qualified and experienced Clinical Allergy Consultant is even more favourable. Any of these suggestions are more likely to result in a more relevant outcome for the enquirer than an IgG test.

Related posts:
Food intolerance testing and migraine
Truthiness and referenciness make the case for IgG food intolerance tests
More allergy and intolerance testing nonsense: part 1
More allergy and intolerance testing nonsense: part 2
Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science
What is the Significance of IgG Antibodies and Testing?
Why IgG Testing for Food Intolerance Is Not As Simple As ABC or Doh Ray Mi

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Monday, March 05, 2007

Views on Allergy UK's Stolen Lives Report and Statistics

Sign text reads: Peanuts and peanut dust everywhereAllergy UK launched their Stolen Lives report during Food Allergy and Intolerance Week in the UK. I have concerns about the value of that report and the uncritical way that its claims were reproduced in the UK media.

So, it has been comforting to learn that there have been some rather more robust appraisals. Steve Carper says that:
[t]he kerfluffle started by Allergy UK's moronic poll alleging to prove that one-third of the total British population has food intolerances and allergies continues to roil nicely.
He highlights Dr. Miriam Stoppard's article in The Mirror:
WE'RE asked to believe that nearly half of us are intolerant of one food or another.

I've never heard such rubbish. And this particular rubbish is masquerading as "science" in a survey published a couple of days ago by Allergy UK, a medical charity.

The report feeds into the current fashion for food intolerance. And it's dangerous because someone suspecting they have an intolerance will feel free to go on an exclusion diet, omitting important, nutritious foods without prior diagnosis and without supervision.

As you might suspect there's a commercial agenda.

There are a number of commercially available tests for food intolerance that their manufacturers claim will make the diagnosis for you. They're suspect, unreliable and scientifically unproven. The commonest intolerance - lactose (milk) - is due to a shortage of the enzyme lactase, needed to absorb lactose.

...

Let's keep a sense of proportion here. With food intolerance you can usually get away with simply cutting down on the offending food.
It's good to see that Dr. Stoppard presenting such a straightforward view. Several TV and media doctors quote Allergy UK's statistics as if they were from a validated epidemiological study, rather than an opinion poll. Some of those same TV and media doctors have voiced some support for IgG testing in the diagnosis of food intolerance but a number of them also have connections with YorkTest and similar commercial laboratories.

It would be useful if some of the media doctors were a little more forthcoming of their criticisms of the value of food intolerance tests. It is disappointing that some of the more critical investigations have been left up to The Mirror. E.g., FAD OF THE LAND, Food Allergy Craze Can Damage Your Health and Pocket.
new research shows we could be wasting our money and actually damaging our health by self-diagnosing allergies that simply don't exist...

Catherine Collins, chief dietician at St George's Hospital in south London, has experienced an alarming increase in young people demanding treatment for allergies when there is nothing wrong with them...

ANOTHER major risk of diagnosing a food allergy yourself is that you could overlook a genuine illness.

Catherine says: "Often people will just cut out certain foods rather than visit their doctor.

"But if they had gone to their GP they might have discovered that the bloating was caused by a serious bowel condition."
Patrick Holford recently suggested that the objection to IgG testing for the diagnosis of food intolerance is a reflection that:
some health professionals just haven’t kept up to date. Perhaps it’s because a ‘home test’ takes the power away from the professional and puts it in your hands.
I would suggest that it's because there is negligible published evidence of sufficient quality to support the role of IgG testing in food intolerance and because concerned professionals have genuine reservations about their potential for harm.

Related posts: Asthma and Food Allergies: Fashion or the New Form of Spiritual Re-Awakening?
Some Sticky Numbers and Comparisons for Food Allergy and Intolerance

For more information about the image used in the illustration, click on it or visit the detail on Flickr.

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Thursday, March 01, 2007

More Allergy and Intolerance Testing Nonsense: Part 2

Pirate Mosaic
Allergy Magazine has recently published a feature on DIY Diagnosis. There is a reasonable introductory summary about the difficulties of gaining access to allergy diagnosis and management on the NHS. There is the usual sloppiness about referring to allergies and intolerance as if they are synonymous. The author uncritically reproduces a number of claims that are frequently repeated but I have yet to see substantiated:
[h]aving an allergy is now one of the most common health complaints in the UK, affecting an estimated 23 million people and four out of ten school children. Up to 40 per cent of the population are sensitive to the three most common allergens: dust mites, pollen and pets. Millions more are intolerant to certain foods, most commonly wheat and dairy.
There is the usual pop quiz where the reader is told that if they have 3 or more of a 16-item list of symptoms then they might have an allergy or food intolerance. The symptoms are the usual suspects: irritable bowel syndrome; constipation; bloating; migraines; anxiety; sinusitis; joint pains; fatigue; low immunity; itchy skin, rashes and eczema; acne or dry skin; itching, swollen lips and face; coughing or wheezing; shortness of breath; dry, itchy throat; diarrhoea or vomiting. Dr. Hadler writes about the medicalization of misery and would probably like a hands-up by anyone who hasn't experienced several of those symptoms over the last year.

The writer does make a handwave towards acknowledging that
[t]here is no clinically proven test for food intolerance yet, but the IgG blood test is the only test with scientific evidence to back up its reliability. [Emphasis added.]
She quotes advice from experts on what to look for in a test.
Liz Tucker, allergy nutrition expert and wellbeing consultant says, ‘Research any test well before you jump in. Some tests are very accurate and have scientific evidence to prove it. But others have no records of accuracy and no evidence to prove it works. Always go for a clinically validated test.’
Liz Tucker is one of the YorkTest-styled experts who endorses YorkTest's range. According to the writer of DIY Diagnosis,
Alex Gazzola, author of Living with Food Intolerance...agrees: ‘Don’t take advice from unqualified people offering unvalidated tests on the high street. I would avoid any test that has not been validated scientifically.’
Gazzola's book is available from YorkTest and endorsed by Allergy UK's Muriel Simmons. At some point, it would be very helpful if somebody other than this self-referential pool of experts were to claim that these tests are clinically or scientifically validated and provide a summary of the research to prove it.

I did have high hopes that I might see some evidence for scientific and clinical validation for allergy and intolerance testing when I read:
Imutest is a clinically proven IgE allergy test, just like those used in hospital laboratories. In a study of 200 patients referred to an NHS allergy clinic for allergy tests, Imutest correctly identified allergies present with an accuracy of 98% in comparison to the gold standard laboratory test method.
I tried to consult Imutest's website but it seems that they have recently gone into receivership. I searched Entrez PubMed and could not find a reference to Imutest. I contacted the journalist but it seems as if this claim was made in the material that was sent to her by Imutest and she no longer has the background research that she did for the piece. That's unfortunate: I don't have much disagreement with a well-conducted IgE test but I would have liked to have seen the reference. At the risk of sounding like a broken record, I don't think that a test result is sufficient as a stand-alone diagnosis; a good diagnosis also depends upon a good clinical history that is interpreted by a clinician with relevant qualifications.

DIY Diagnosis refers to several YorkTest products: the YorkTest Food Intolerance Indicator, the YorkTest 42 Foodscan, the YorkTest 113 Foodscan and the Yorktest Multi-Allergy Screening Test. She writes the following about the reliability of the YorkTest tests:
All tests are highly accurate in diagnosis between 95 -97%. For the Foodscan range, 70% of those tested who followed the advice given reported an improvement in their symptoms.
I have looked high and low for an authoritative source for these claims about the YorkTest tests. I can't find them. I have seen these claims so often that I have to assume that there is reputable and substantial scientific literature to back them up but I have to declare that I have so far been completely unsuccessful in finding that research.

The journalist indicates that she discriminates between reliable, authenticated tests and those of a more dubious provenance. She mentions the BEST (Bio Energetic Stress Test) system and makes this comment about its reliability:
[c]urrently there is no clinical evidence to support this method of testing.
I would say that the current position of relevant professional bodies is that there is no clinical evidence to support the use of IgG testing in the diagnosis of food intolerance (more on the lack of support for IgG testing).

1. ARR!, 2. Yo ho ho, 3. Rogue Orange, 4. My New Pirate Hat

Created with fd's Flickr Toys.

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Is YorkTest Petitioning for Food Allergy and Intolerance Tests on the NHS?

Cat with rifle poised at a window. The caption reads When all else fails, vote from the rooftopsThere is an extraordinary synergy at work about IgG, food allergy and intolerance testing that is sending shivers down my spine. Yorktest has made some extravagant claims for the significance of an Allergy UK-sponsored audit of its foodSCAN test and its efficacy for chronic conditions.

In an excited news item*, YorkTest promotes an obscure petition to provide free food intolerance tests on the NHS. Their pious hope for the petition is that:
[t]he people behind the idea of having free food tests must hope they too get an email from the Prime Minister. It re-enforces the view that the NHS should put peoples health at the forefront of its health service strategy. If the petition takes off, then it could make the health minister sit up and take action in saving the health service thousands of pounds whilst freeing up doctors valuable time.

At best this petition might make the stakeholders of the health service to look at what is best for the people it aims to help and accept it as a credible and fast alternative to dishing out a diet of pills and potions. [I have not sic'd the errors. Emphasis added.]
"These people"...one might assume that the oppressed hordes of people who have been mistreated by the NHS have thrown off their shackles, and like so many Howard Beales, gone to the window and shouted "I'm mad as hell and I'm not gonna take it anymore!" The optimism and altruism are inspirational. Or they would be were it not for a remarkable coincidence. It seems as if the founder for this petition is Les Rowley. Is it at all possible that this is the Les Rowley who is listed as YorkTest's media contact? Do you think that we should be told?

In yet another extraordinary coincidence, somebody called Gemma Hicks has signed the petition, and somebody by that name is a contact point for YorkTest.

I first saw the GoPetition.com version of the petition which declares:
The NHS treats 1 million patients ever 36 hours. For every patient the government spends on average £6,762 a year. These are significant costs to the tax payer yet the NHS are letting down patients by not getting many of them better. Food intolerance testing could save the NHS billions of pounds, and get patients better quicker.

A recent survey suggests that 66% of patients use the NHS for at least three years (32% for ten years of more) before patients take matters into their own hands and get better using food intolerance testing. [**]

We propose to petition the Government to allow the NHS to prescribe food intolerance tests as a way of combatting a number of chronic illness. It has a duty to serve its patients and the tax payer.
However, the founder of that petition is simply identified as 'Les'. It is the 10 Downing St. PM Petition version that names Les Rowley of FIAG as the founder: the petition is the same. By the by - the website is just a domain holder, there is no information about FIAG or Les' affiliations.

If this is the same Les Rowley who is connected with YorkTest then I would ask him to consult the introduction to e-petitions; in particular the part that reads
The e-petition system has been designed to be transparent and trustworthy.
Is is just me, or does this e-petition fail on those criteria? Which doesn't even address the shoddy science behind the petition's claims.

*Just in case this item inexplicably disappears, like a recent piece by Patrick Holford, I have taken the liberty of reproducing 28/02/07 Free food intolerance test says government petition.
Recently these petitions have become a launch pad for ideas and new thinking and whether they will influence government strategy is debatable. Tony Blair was forced to email 1.3 million people who had signed an online petition over road pricing. Although the signatures will not necessarily change the law, the Prime Minister felt he had a duty to spell out the government's transport policy.

The people behind the idea of having free food tests must hope they too get an email from the Prime Minister. If anything it re-enforces the view that the NHS should put peoples health at the forefront of its health service strategy. If the petition takes off, then it could make the health minister sit up and take action in saving the health service thousands of pounds whilst freeing up doctors valuable time.

At best this petition might make the stakeholders of the health service to look at what is best for the people it aims to help and accept it as a credible and fast alternative to dishing out a diet of pills and potions.

Log on to http://petitions.pm.gov.uk/freefoodtests and see what all the fuss is about.
**The observant Dr. K has noticed that the wording of this petition has been bungled in such a way that it now claims that:
66% of patients use the NHS for at least three years (32% for ten years of more) before patients take matters into their own hands and get better using food intolerance testing.
So, that would now imply all patients of the NHS, not just those who shared their anecdotes and truthiness for the study.

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More Allergy and Intolerance Testing Nonsense: Part 1

Images of pirates engaged in various activities
Recently, I commented on Hardman and Hart's recently published audit of YorkTest's IgG-guided food elimination diets and chronic medical conditions. Although the survey was sponsored by Allergy UK it is a poor study that does not provide enough detail to be able to evaluate either its conclusions or its publicity. I had hoped that the study was so self-evidently incapable of supporting swashbuckling or grandiose claims that people who profess an interest in decent science or a reputable evidence base would not over-state its significance.

YorkTest has published a summary of some of the paper's findings that make substantial claims about its significance and criticises the NHS: 10 Years of NHS treatment and still we're ill says study. I must reiterate at this point that the survey does not include any verification of the participants' claims about when they first reported the symptoms to a GP or representative of the NHS. There is no summary of medical treatments that the participants followed and whether any of them were being followed at the time of the YorkTest 113 foodSCAN guided elimination diet.

Allergy UK and YorkTest have been talking up this audit for some time. I've seen references to more than 7000 participants, 5000 participants, and for the relevant claim about unsuccessful treatment by the NHS, this is now modified further:
T[t]he findings, conducted by York University, suggest a growing dissatisfaction among patients who wasted time and money on treatment on the NHS. The study using 3219 patients and published in the February issue of Nutrition and Food Science looked at a range of mild and chronic illnesses including migraine / headache, skin symptoms, IBS, and digestive problems.
Elsewhere on their site, YorkTest summarises the YorkTest 5200 Patient Survey (aka Testing Times report [pdf] which is an advance version of the journal paper).
Three months after taking a 113 foodSCAN test, we send a satisfaction questionnaire out to our customers to find out how they are getting on, what benefits they have experienced and how they felt about the test and service. This independently audited report has been produced to provide evidence that an elimination diet based on food-specific IgG results is an effective, reliable and valid aid to the management of chronic conditions. This will be published in February 2007 in the International Journal of Nutrition and Food Science.
This was a perfect opportunity to disseminate all of the data that it wouldn't have been practical to include in the journal paper. Why have neither Allergy UK nor YorkTest made the full detail of this study available? According to the journal paper, the data are drawn from a questionnaire with scaled category responses, yet, according to the current claims, it now seems as if the participants were invited to complain, or spontaneously complained about their NHS treatment. However, from YorkTest's own summary it now seems as if they are referring to a "satisfaction questionnaire". Is this why there was a different version of the questionnaire? If it was YorkTest's own customer satisfaction questionnaire than why did Allergy UK pay for the audit? I'm sure that there are some straightforward explanations but all of these different descriptions make it very confusing.

Does YorkTest usually ask its customers for information about their NHS experiences? Was this question only added in for the Allergy UK-sponsored audit? What were these questions about the NHS? How were they phrased?

The paper's claims can not be substantiated or evaluated without this information. It is time to publish the questionnaires and the full data from this audit. Without the full information it is impossible to evaluate the claims that are being made and that is an unsatisfactory situation that may well lead to many mis-understandings and might mislead some desperate people. I am particularly annoyed that it seems as if somebody associated with YorkTest may be attempting to use these findings as the basis of an e-petition to have food intolerance tests made available on the NHS.

For years we have been told, "The evidence is coming. Trials are in progress" and this is what we get?

Images courtesy of Flickr. 1. Pirate, 2. Pirates, 3. Pirate Contemplation, 4. Yarr there be Pirates!

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Tuesday, February 27, 2007

Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science

Cat with rifle poised at a window. The caption reads When all else fails, vote from the rooftopsThis year I have read a number of poor papers and a remarkable number of assertions that rely upon quote mining or misrepresentation to conjure up scientific respectability for some very dubious claims. A lot of this experience and disillusionment is related to the literature and claims around IgG testing for food intolerance despite the published position of relevant professional associations that find no support for the clinical use of IgG testing for food intolerance.

I've addressed the matter of Patrick Holford's endorsement of IgG food intolerance tests in a previous post. Holford is a nutritionist for whom recommending these tests is an expansion of his own commercial offerings so his endorsement in understandable although his claims of "sound science" behind IgG testing are not. I'm rather more troubled by Allergy UK's endorsement of IgG testing; particularly because they presented evidence to a Select Committee on Health that they deal with 60,000 requests for assistance in a year, and say that "the number of people seeking advice had grown on average by 21% in each of the last three years". It is obvious that people turn to them in expectation of authoritative information. Allergy UK is a medical charity; people who request assistance might expect their endorsements to be thoroughly researched and a reflection of current bio-medical research and opinion.

Muriel Simmons of Allergy UK is liberally quoted by a commercial laboratory that offers direct-to-consumer testing (YorkTest): she is quoted as endorsing a number of their allergy (e.g., the multi-allergy screening test) and intolerance tests. Surprisingly, the Allergy UK website does not provide a summary of the research to support this position on their website. There is a buried reference to Whorwell's paper that investigated IgG testing and an elimination diet in the treatment of irritable bowel syndrome (IBS). Although others may have quote-mined or misrepresented the extent to which their work can be generalised, Whorwell and his co-authors responded to comments about their reported findings and were punctilious in defining the limits of a reasonable interpetation of their results:
it is entirely possible that IgG antibodies may be important in IBS, where we now know that there is an inflammatory component in some cases, whereas they may not be relevant in food intolerance in general. Furthermore, it is likely that only a subset of patients are likely to have an immuno-inflammatory basis to their condition and these might be the very individuals who respond to dietary exlusion based on IgG antibodies. This would fit with our results where only a proportion of patients responded despite all having antibodies. This, of course, limits the specificity and usefulness of the test unless such subgroups can be indentified beforehand. [Emphases added.]
For several years, Allergy UK and YorkTest have made references to research that is in progress. Some of this research was published recently and addresses Dietary advice based on food-specific IgG results.

The PR release for the Allergy UK-sponsored study claims the following:
The new study...is the largest ever food intolerance study undertaken in the UK and reveals for the first time that over 60% of patients involved in the study had to endure over 3 years of NHS appointments, suffering and misdiagnosis before obtaining improvement through the food intolerance testing.

5200 people took part in the study and were treated for a wide range of mild and chronic illnesses. In addition, nearly a third of all patients received NHS treatment for over a decade without success. 32.4% of the sample showed they had suffered with their condition for over ten years before taking up a food intolerance health solution.

At the other end of the scale just 5% of patients had illnesses lasting from 1-6 months before using food intolerance and 22% were upto 35 months before seeking a non-NHS resolve via food intolerance testing.
Other PR-reported findings in the study reveal:
  • Over 3 out of 4 patients get better from their original symptoms.
  • 68.2% of patients benefited within the first three weeks.
  • 9 out 10 patients had a return of symptoms when introducing offending foods back into their diet.
  • Many patients would rather have a dietary solution than taking medication.
  • Patients who reported more than one condition were most likely to report improvement.
  • On average, patients had symptoms for at least 10 years before taking up a food intolerance option.
[Edited 1 March.YorkTest has made some remarkable claims about this study: 10 years of NHS treatment and we're still ill*.] I find these claims to be a little extravagant when there that is no attempt to obtain objective measurements, nor attempts to correlate with medical records and the study covers a 3 month period but I was optimistic that access to the full paper would resolve my misgivings.

I located a copy on Gillian McKeith's site (it is possibly a pre-publication copy). I was hopeful that the paper would answer some of my questions, particularly as it has been bruited about as having significant findings about IgG food intolerance testing, dietary modification and chronic illness.

I have been disappointed on a number of fronts. Other issues aside, it is bewildering that Hardman and Hart refer to the survey participants as patients: neither of the authors is medically qualified and there is no indication within the paper that those who responded to the survey are under medical care for their self-reported symptoms or illnesses. By referring to patients the authors imply that all of the participants are patients and that there may be some form of validation for their symptoms and illnesses. It is understandable that the PR release lards its text with references to the NHS, treatment, and patients but it is potentially misleading if it leads people to believe that this work is NHS endorsed or was being offered as a treatment programme.

There is no explanation as to why there are two questionnaires, nor do the authors provide a clear list of the differences between them. Participants received one survey, 3 months post-test: there was no recorded baseline of symptoms and diet. Any claims about either symptoms or diet must be retrospective. Further, we don't see the questions so it is difficult to evaluate some of the claims and findings and how the response may have been manipulated by the form of the question.

The postal survey does not tell us what the respondents were eating before their intolerance testing. If people have been speculating about food problems in relation to their illness for some time, it is possible that they may have experimented with an elimination diet that may have skewed the results of their IgG testing. E.g., if somebody had been avoiding soya for some time they would probably have a negative IgG test at that time whereas they might have a positive result with recent exposure.

Likewise, it would not be too difficult to imagine that people who are chronically tired or experiencing 'brain fog' might not prepare food from scratch on a regular basis. It is possible that the striking improvements in well-being might occur in anyone who shifts from a diet of processed food to home-prepared 'healthy' meals. The best way to test this would be to find a group of people who are chronically tired etc. but switch them to a more wholefood way of eating without any food intolerance tests. Actually, that sounds like a number of diet makeover T.V. programmes which show startling results when people change their way of eating (although, to be fair, they usually start exercising as well).

The participants in this survey had previously purchased a direct-to-consumer 113 foodSCAN test from YorkTest. They sent a small blood sample to the laboratories for testing. The testing evaluates the level of IgG in response to the panel of foodstuffs. The consumers receive a report in their levels of food-specific IgG are listed, and they are advised to avoid those foods with increased antibody levels (the red, yello and green system). The lab results are accompanied by helpful food lists and food rotation instructions. As part of the service package, the consumers have limited phone time with a nutritional adviser.

Hardman and Hart do not discuss the IgG results: it would have been interesting to know if the positive IgG results clustered around the usual suspects of wheat, milk, shellfish, citrus fruits etc. or if they were evenly spread throughout the 113 test foods. An analysis like this would be valuable in designing a placebo diet for use in any future research involving IgG-guided elimination diets.

A high number of survey participants claimed to have "rigorously followed their elimination diet" however, this depends on their subjective assessment and recollection. There is no reference to any request that participants should keep food diaries so these recollections may be unreliable. Even those participants who made a "reasonable attempt at the diet" (N.B., there is no explanation of what this means) reported "noticeable improvement". So, these findings may suggest that making a few changes, which may not necessarily reflect the IgG testing results, is effective enough to question whether it is worth the added inconvenience of implementing a rigorous elimination diet.

There is remarkably little discussion of the finding about the relationship of response to the food elimination diet and symptoms:
The information obtained from asking which was the primary condition that concerned patients was grouped into diagnostic categories. As previously mentioned this question was not asked of all patients as it was only part of the first questionnaire. Of the 2221 replies 38.0% were gastro-intestinal, 13.7% were dermatological, 10.7% were neurological, 10.1% were respiratory, 9.4% were psychological, and 6.2% were musculo-skeletal. 11.9% were categorised as ‘other’.

The distribution of benefit reported varied according to the medical condition of most concern...For example, 40.6% of patients reporting psychological problems as their main concern report high benefit from dieting rigorously, whereas only 21.0% of those reporting respiratory or musculo-skeletal problems as the main concern reported high benefit. [Emphasis added.]
It does have to be said that some of these results would be comparable to a placebo condition: in an IBS study, the researchers "estimated that approximately 40% of the placebo arm would report a significant improvement in symptoms". Hardman and Hart summarise their audit of the survey:
All the measures considered were categorical and based on self reported perceptions so quantification of comparisons was not possible. However, there was consistent evidence that noticeable benefit was gained from removing offending foods from the diet. 75.8% of those that rigorously followed the recommended diet had a noticeable improvement in their condition. 68.2% of those that benefited from following the recommendations felt benefit within 3 weeks of following the diet. The survey covered subjects with a wide range of medical conditions, and it was clear that those who reported more than one condition were more likely to report noticeable improvement. 81.5% of those that dieted rigorously and reported three or more co-morbidities showed noticeable improvement in their overall condition.
The authors reported some widely different findings about challenges with the 'offending' foodstuffs.
Subjects were asked specifically to say whether the result of reintroducing foods was a strong return of symptoms, a slight return of symptoms, or no change. Of the 3026 subjects that responded to the second questionnaire, 2275 (75.2%) said they had reintroduced offending foods either on purpose or by accident. 2219 of these patients also answered the question regarding the return of symptoms. 824 (37.1%) reported a strong return of symptoms, 902 (40.6%) reported a slight return of symptoms, and 493 (22.2%) reported no change. That is 77.7% reported the return of symptoms after the reintroduction of offending foods...

Those reporting more benefit were more likely to feel a return of symptoms after reintroducing offending foods. For those who dieted rigorously and reported high benefit, 92.3% felt a return of symptoms after reintroducing offending foods.
Obviously, the participants were typically aware that they had eaten "offending foods" and it is probable that this is reflected in the results. It would have been interesting to have had a breakdown of the symptoms or conditions that were most likely to recur upon re-introduction of "offending foods" and what these foods were.

When people follow elimination diets, it is not unusual for them to adopt a de facto low carbohydrate way of eating. This may be particularly true when consumers are guided by the results of a food intolerance test because if they are advised to eliminate foods such as wheat, they may find it difficult to replace this with another (safe) carbohydrate source. They may be unwilling to replace (say) wheat with quinoa if they were not tested for quinoa. So, it is possible that a number of people in this survey who showed the strongest reaction to the reintroduction of foodstuffs might have been exhibiting a reaction that reflects a disturbed glucose metabolism that is related to carbohydrate restriction. Bethune and colleagues have previously reported that this phenomenon can be interpreted as food allergy.
All three of the patients described developed symptoms several hours after meals and attributed these to food allergy. Further restriction of carbohydrate intake exacerbated their problem. Symptoms continued to occur after meals and were erroneously interpreted as further evidence of their carbohydrate allergy.
The researchers discuss 3 case studies and report that
[o]nce patients have a fixed belief about a cause for their symptoms, it may be difficult to persuade them to entertain an alternative diagnosis. In case 1, negative results of blinded food challenges did not dissuade the patient from her belief that food allergy was the cause of her symptoms.
Because Hardman and Hart report on their audit of the YorkTest 113 foodSCAN but do not provide sufficient detail in the paper, the reader is reduced to speculating about plausible mechanisms for the results. There is no reminder that these results only cover a 3 month period, we do not know if the reported improvements persisted. The authors conclude:
The observation of a clear relationship between adherence to the diet and outcome is critical in showing that the diet is an ‘active treatment’. Similarly the fact that over three-quarters of subjects who reintroduced offending foods back into their diet, whether on purpose or by accident, showed reoccurrence of their symptoms. These two criteria are the basis for the diagnosis of ‘food intolerance’ by the laborious elimination diet process which, it appears, can be largely ‘bypassed’ by following a diet based on the results of food-specific IgG testing. The percentage of patients reporting noticeable improvement suggests that such specified elimination diets are a valid intervention in the relief of certain symptoms. The degree of success varies with the type of problem being experienced.
I can not agree that these survey results support these conclusions. Without examining well-maintained food diaries, it is impossible to quantify the number of people who did alter their diet rigorously: the results indicate that even those who followed an elimination diet of some sort (that does not necessarily adhere to the IgG results) will produce results and therefore qualify as an "active treatment".

Similarly, Hardman and Hart are not entitled to claim support the diagnosis of food intolerance based on the reaction to the reintroduction of "offending foods" because the participants did not attempt a blinded food challenge. Young and colleagues published a classic population study of food intolerance where there was a perceived prevalence of food intolerance of almost 20%, but the clinically definitive double blind placebo food challenge test indicated a rate of less than 2%.

Hardman and Hart acknowledge the equivocal status of IgG as a marker for food intolerance in the introduction:
the exact role of IgG antibodies as markers of food intolerance in general is not clear. IgG antibodies to food antigens are often present in healthy individuals and are generally considered to be part of the normal immune response to food allergens [refs].
However, they do not comment any further on this in their discussion of the findings of this audit. I hope that this reticence is continued by others and that there is no attempt to misrepresent this audit as supportive of the "sound science" of the IgG diagnosis of food intolerance or the "clinically validated" virtues of an IgG-guided elimination for the treatment of a variety of symptoms and chronic medical conditions.

In the UK we have very poor provision of allergy diagnosis and management. People report that GPs are wary of the validity of allergy and intolerance and that it is very difficult to obtain a referral to the limited NHS services that do exist. The cause of appropriate allergy provision may be damaged by its association with the dubious science of food intolerance testing.

A diagnosis of food allergy should be confirmed by a clinician with an understanding of the multisystem, polysymptomatic patterns of illness involved. A careful history will usually reveal these patterns and suggest a diagnosis that can be made on clinical grounds. Clinical allergists rely upon an interpretation of the history and the tests; however, there is no wholly definitive laboratory test because an interpretation of the results relies upon the clinician's understanding of somebody's complex allergic responses. E.g., a clinician may need to interpret the individual and relative levels of several antibody series, such as IgE, IgG, IgA and IgM. There may be complex shifts in the distribution of IgE, IgG, IgA and IgM that indicates immune activity in response to antigen loading. Patients who have severe or prolonged food allergy may have depressed levels of IgM and IgG; they may also have lower white cell counts. If IgE levels are low, this may compromise the clinical value of both skin testing and IgE RAST. Overall, a high IgG might be associated with an immune-mediated diseases, and reflect increased antibody production, possibly against unknown antigens.

The status of IgG testing in diagnosing food intolerance is controversial. It is premature at best and boarding on deceptive to claim that IgG testing for food intolerance is "clinically validated" or has "sound science" behind it. There is so much mis-information on the internet that it would be helpful if the British Society for Allergy and Clinical Immunology (BSACI) would issue a position statement on the matter (however, Prof. Kay, a former president of BSACI has made some lack of scientific support for this use of IgG testing). Both BSACI and Allergy UK are core members of the National Allergy Strategy Group. Membership of such bodies adds to the status and authority of Allergy UK and their endorsements. It is unfortunate that Allergy UK gives the imprimatur of respectability to IgG testing in the diagnosis of food intolerance.

*Allergy UK and YorkTest have been flagging up this audit for some time. I've seen references to more than 7000 participants, 5000 participants, and for the relevant claim about unsuccessful treatment by the NHS, this is now modified further:
The findings, conducted by York University, suggest a growing dissatisfaction among patients who wasted time and money on treatment on the NHS. The study using 3219 patients and published in the February issue of Nutrition and Food Science looked at a range of mild and chronic illnesses including migraine / headache, skin symptoms, IBS, and digestive problems.
Why have neither Allergy UK nor YorkTest made the full detail of this study available. According to the published paper, this was a questionnaire with scaled category responses. However, from the current claims, it now seems as if the participants were invited to complain, or spontaneously complained about their NHS treatment. This study is very poor; the claims being made for it are over-blown and disproportionate. Readers can not possibly assess these claims of NHS mis-treatment or mis-guided treatment if we have no way of discovering which treatment modalities were attempted.

YorkTest also has the chutzpah to promote an obscure petition to provide free food intolerance tests on the NHS. Their pious hope is that the petition:
re-enforces the view that the NHS should put peoples health at the forefront of its health service strategy. If the petition takes off, then it could make the health minister sit up and take action in saving the health service thousands of pounds whilst freeing up doctors valuable time.

At best this petition might make the stakeholders of the health service to look at what is best for the people it aims to help and accept it as a credible and fast alternative to dishing out a diet of pills and potions. [I have not sic'd the errors.]
There is no decent science behind IgG food intolerance testing. Leaving that issue aside, YorkTest is now claiming that an IgG-guided elimination diet is a "credible and fast alternative"? Unusually enough, words fail me. [Edited: It is possible that somebody associated with YorkTest instigated this e-petition.]

It is time to publish the questionnaires and the full data from this audit. Without the full information it is impossible to evaluate the claims that are being made and that is an unsatisfactory situation that may well lead to many mis-understandings.

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