Ask the Expert

I have seen several patients who have had Biotek testing for various symptoms. The test combines IgE plus IgG to a host of foods and there is no clinical correlation with the results. They have been ordered by "natural doctors" or chiropracters. I get the privilege of explaining the tests to these folks. Is there any recent commentary I can offer to invalidate these tests? I feel it is a growing problem.

Thank you for your recent inquiry.

There are two recent sources that speak to the issue of IgG antibodies to foods (1, 2). Below you will find, for your convenience, a quote from each article summarizing the opinions of the authors regarding the clinical utility of IgG anti-food antibodies. The first quote is from the Sicherer/Sampson article, and the second is from the Parameters.

Thank you again for your inquiry and we hope this response is helpful to you.

Quote 1:

"Unproved or disproved tests, such as the pulse test, applied kinesiology (muscle strength tests), cytotoxic tests, electrodermal tests, and IgG testing, should not be used."

Quote 2:

"Although it is recognized that food allergen-specific IgG may be found in many normal and allergic individuals, there is insufficient evidence that the presence or quantity of food allergen-specific IgG produced as a result of natural exposure is related to allergic disease. Further, the measurement of subclass specific IgG, antibodies to foods has been inconsistent between various studies. Thus, food-specific IgG or IgG, antibodies have no recognized diagnostic value."

References:

Sicherer S and Sampson H. Food allergy. Journal of Allergy and Clinical Immunology, February 2010; 125(2):S116-S125 (Supplement 2).

Allergy Diagnostic Testing - an Updated Practice Parameter. Annals of Allergy, Asthma, and Immunology, March 2008; 100:S1-S148.

Sincerely,

Phil Lieberman, M.D.