Avidity of antigliadin IgA and IgG antibodies in gluten-sensitive enteropathy and dermatitis herpetiformis.

Antigliadin antibodies (AGA) of IgG and IgA class were assayed with a modified enzymeimmunoassay in serum samples of 18 patients with gluten-sensitive enteropathy and 30 patients with dermatitis herpetiformis. No difference between antibody amount or avidity of the two groups of patients was observed. Avidity and total amount of AGA were also compared in 15 patients with a recent diagnosis of dermatitis herpetiformis and in 15 patients with a disease history of several years without a proper gluten-free diet. No difference in IgG antibodies was found but the amount of high avidity IgA antibodies was significantly higher in patients with several years' experience of dermatitis herpetiformis than in those with a recent diagnosis. The results indicate that in dermatitis herpetiformis, maturation of IgA response occurs. Further, clinically, maturation of anti-gliadin IgA response during the disease can increase the sensitivity of the patient against diet-derived gliadin.