Characterization Of Serum Antigliadin Iga In Childhood Celiac-Disease Versus Other Gastrointestinal-Diseases And Controls

Titers and molecular sizes of anti-gliadin (GL) IgA were compared in the serum of 3 groups of children : (1) 100 “normal” controls, (2) 100 controls with several gastrointestinal diseases (acute gastroenteritis in 82, inflammatory bowel disease in 4, cow's milk allergy in 10 and cirrhosis in 5), (3) 19 coeliac diseases (CD) (13 untreated and 6 on gluten challenge). Anti-GL IgA were detected by solid-phase radioimmunoassay, and their molecular size was analyzed in all sera with > 40 arb.u. antibodies by sucrose density ultracentrifugation gradients. Anti-GL IgA titers were higher in untreated CD than in all other conditions (p<0.001), but some overlap of the antibody titers were noted. Though total serum IgA was 80% monomeric (m-IgA), 47% of anti-GL IgA was polymeric (p-IgA) in untreated CD. These antibodies were mainly dimeric and not complexed with secretory piece. After one month on gluten-free diet, anti-GL IgA titers were dramatically lowered, due mainly to the disappearance of p-IgA antibodies. In contrast, 83% of anti-GL IgA were m-IgA in 5 positive controls and respectively 85% and 79% were m-IgA in 2/6 positive CD during gluten challenge.