IgA - What We Know

This is a great piece on IgA antibody testing from the lab that we use (US Biotek Laboratories) at the IBS Treatment Center.

From USBiotek.com:

• Impairment of humoral and mucosal immune responses, or oral tolerance, plays a contributing role to the pathogenesis of disease. The breakdown of this tolerance may result in abnormal processing of food proteins in the gut resulting in pro-inflammatory food antigen handling.

• Research studies suggest elevated serum antibodies, IgE, IgG or IgA to food proteins are markers of this immune intolerance. For example, elevated IgA antigliadin is a proven useful marker of the immune reaction in the small intestine triggered by gluten, in celiac disease.

The immunological trigger effects of specific-IgA antibodies merit close consideration for the screening and management of chronic inflammatory disease conditions where there is a suspected loss of oral tolerance.

IgA represents a primary immune reaction. The half-life is about 5-6 days, compared to IgG which is about 20-24 days, and indicative of an ongoing immune reaction. The assessment of the both antibodies offers a comprehensive picture.

IgA antibodies provide early defense against many antigens. IgA in the form of secretory IgA, sIgA, is produced from initial exposure to antigen. It represents local or mucosal immunity. sIgA binds and excludes antigen present in the intestinal tract, preventing excessive systemic absorption, for example, food peptides, bacteria, viruses, protozoa and fungi; proteins that are normally restricted to the intestinal tract.

IgA antibody is found in many mucous secretions other than that of the gut for the same purpose of immune exclusion including saliva, tears, respiratory and genitourinary tracts.

It continues...

Unfortunately there is no hard and fast rule on when to order IgG vs. IgA or both. Both IgA and IgG may be present in a variety of chronic inflammatory disorders.

Many of the references on food-specific IgA testing are in regards to Celiac/Gluten sensitivity, as this is one of the more popularly studied conditions.

A preferential increase in serum antigliadin IgA has been demonstrated in gut diseases like Celiac, Crohn’s, Ulcerative Colitis in addition to Rheumatoid Arthritis, Bergers’ disease and Henoch-Schonlein Purpura (HSP). Antigliadin IgA is considered a marker of mucosal damage in childhood celiac disease. The presence of IgA-gliadin immune complexes in serum of children with HSP suggests gut mucosal alterations with an increase in intestinal permeability. Food specific IgA has been demonstrated in IgA nephropathy for reasons yet unclear (e.g.: possible IgA immune regulatory abnormality, hepatic clearance defect).

IgA antibody panels can be run individually or in conjunction with IgE and IgG antibody tests. IgA antibody panels are available for exactly the same panels as have been offered for IgG and IgE testing. (For a complete list of the foods against which an immune reaction can be tested, please visit IBSTreatmentCenter.com).

If you would like to run IgA testing, or have yet to run any tests with us, please contact our office to schedule an appointment at 888-546-6283 or info@ibstreatmentcenter.com.