ImuPro, not good enough evidence, again!

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Posted 26 November 2013

wellproimupro-logo ImuPro has been featured numerous times on CamCheck for making unsubstantiated claims for this test -and have been ruled against by the ASA. Originally only making tests for the benefit of ImuPro for allergies and intolerances, these have eventually been removed following a protracted course. 

 

A complaint has been laid against the owner, Dr York, with the Health Professions Council of South Africa (no result yet).

Now we have been informed that Dr York/ ImuPro, are making other not so well supported claims.

On the Well-Pro – ImuPro website (http://www.wellpro.co.za/tests-imupro/), the following claim is made: “Data suggests that eliminating foods that are identified to have an IgG antibody response results in significant improvement in a variety of conditions like migraine (1), Irritable Bowel Syndrome (2), Crohns disease (3) and juvenile obesity (4).”

The study quoted in support of the IgG, i.e., ImuPro testing, benefiting irritable bowel syndrome, is a study conducted by Atkinson et al in 2004.[1]

However, this study is completely misleading and inadequate to support the claims for this test.

In a recent article published in the Journal of Gastroenterology and Hepatology titled “Alternative Investigations for Irritable Bowel Syndrome”[2], the following is concluded[3]:

Serum IgG Antibodies to Food Antigens

Rationale and Clinical Validity
Immunoglobulin G (IgG) antibodies to food antigens may be detected in the serum of normal healthy individuals as well as patients with irritable bowel syndrome (IBS). [[4]] Some groups have demonstrated elevated levels of IgG in patients with IBS suggesting that this may represent an “allergic” response to food. [[5]] The pivotal randomized controlled trial used in support of this approach demonstrated benefit in using a diet excluding foods to which the patient had measurable circulating IgG antibodies over 12 weeks.[[6]] The main problem with this study was that the differences in symptoms were only observed in a minority of patients who were deemed adherent to the exclusion diet. On an intention-to-treat basis, there were no differences between responses in the exclusion and sham diet groups. A second, smaller study also reported similar beneficial results but again did not correlate levels of IgG with symptom severity. [[7]] 

The American Academy of Allergy, Asthma and Clinical Immunology (AAAAI) and the European Academy of Allergy, Asthma and Immunology (EAAACI) have published position statements that highlight the limitations of IgG antibody testing to food antigens,[4] and conclude that the presence of IgG antibodies to food antigens may represent a normal physiological response to food ingestion. 

Analytical Validity
Irritable bowel syndrome is a diagnosis based on symptoms and hence there are no comparable “gold standard” tests to food antigen-specific IgG. The test itself is an enzyme-linked immunoassay (ELISA) and several different companies produce assays. A comparison of three different assays across several different North American laboratories found wide variations in the readings across both assays and laboratories[[8]] 

Clinical Utility
As the measurement of specific IgG in serum may be unreliable and the level of evidence of the efficacy of exclusion diets is limited, treatment based on “abnormally” high antibodies cannot be recommended.

Or particular relevance, the Atkinson study that ImuPro quotes in support of the validity of the ImuPro in benefiting Irritable bowel syndrome, is reported above in this way: “The pivotal randomized controlled trial used in support of this approach demonstrated benefit in using a diet excluding foods to which the patient had measurable circulating IgG antibodies over 12 weeks.[[9]] The main problem with this study was that the differences in symptoms were only observed in a minority of patients who were deemed adherent to the exclusion diet. On an intention-to-treat basis, there were no differences between responses in the exclusion and sham diet groups.”

Significantly, since the Atkinson study, there has not been any further evidence in favour of the claims, but many peer-reviewed publications against the effectiveness.

It therefore means that consumers must be very, very cautious when spending a great deal of money (this test is very expensive) on a test with very limited support.

 


[1] Atkinson W, Sheldon TA, Shaath N, Whorewall PJ. Food elimination based on IgG antibodies in irritiable bowel syndrome: a randomised controlled trial. (2004) Gut; 53: 1459-1464

[2] Hamish Philpott, Sanjay Nandurkar, John Lubel, Peter R Gibson. Alternative Investigations for Irritable Bowel Syndrome. J Gastroenterol Hepatol. 2013;28(1):73-77.

[3] http://www.medscape.com/viewarticle/777478_3

[4] Stapel SO, Asero R, Ballmer-Weber BK et al. Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report. Allergy 2008; 63: 793–6.

[5] Zar S, Mincher L, Benson MJ, Kumar D. Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome. Scand. J. Gastroenterol. 2005; 40: 800–7.

[6] Atkinson W, Sheldon TA, Shaath N, Whorwell PJ. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut 2004; 53: 1459–64.

[7] Zar S, Mincher L, Benson MJ, Kumar D. Food-specific IgG4 antibody-guided exclusion diet improves symptoms and rectal compliance in irritable bowel syndrome. Scand. J. Gastroenterol. 2005; 40: 800–7.

[8] Miller SB. IgG Food Allergy Testing by ELISA/EIA. What Do They Really Tell Us? 2008. Cited May 2011. Available from URL: http://www.tldp.com/issue/174/IgG%20Food%20Allergy.html

[9] Atkinson W, Sheldon TA, Shaath N, Whorwell PJ. Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut 2004; 53: 1459–64.

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