Small intestinal biopsies and HLA types in dermatitis herpetiformis patients with granular and linear IgA skin deposits.

In this study we determined whether dermatitis herpetiformis patients whose skin contained linear IgA deposits differ from those whose skin contained granular IgA deposits with regard to the presence of gluten-sensitive enteropathy and with regard to the prevalence of certain histocompatibility antigens. We performed multiple Rubin tube intestinal biopsies on 11 patients, 6 with linear and 5 with granular IgA deposits. The gut biopsies were evaluated histopathologically in a blinded fashion. We found that none of the patients with linear deposits (5 with lamina lucida and 1 with sub-basal lamina deposits) h-d detectable jejunal abnormalities whereas all of those with granular deposits had jejunal abnormalitites (villous atrophy and increased numbers of intraepithelial lymphocytes). In parallel studies HLA typing was performed in 10 patients with linear IgA deposits and in 49 patients with granular deposits. Only 30% of those with linear deposits had HLA-B8, a prevalence not significantly different from that of the normal population (24%); in contrast, 88% of those with granular deposits had HLA-B8, a prevalence significantly greater than in the normal population ( less than 0.001). We therefore conclude that patients with linear IgA deposits have a disease which is pathophysiologically different from those with granular IgA deposits.