IgA class antibody against human jejunum in sera of children with dermatitis herpetiformis.

Sera of 44 children with dermatitis herpetiformis with granular IgA deposits in the papillary dermis were investigated on cryostat sections of normal jejunum of three children aged 2 months, 1 year, and 10 years by indirect immunofluorescence. Eighteen of 25 patients on a normal diet had an IgA class antibody showing the following staining patterns on substrate jejunums: tubular positivity in the lamina propria--around the crypts, beneath the villous epithelial basement membrane, and in some instances in the middle of the villous also, following the capillary system of villi; coalescence of tubular positivity at the muscularis mucosae; and positive blood vessels and smooth muscle endomysium. Eleven of 18 children with positive sera were put on a gluten-free diet (GFD) and their sera became negative. One of these 11 patients was challenged with gluten and the antibody reappeared. Nineteen patients examined only on a GFD and 30 healthy blood donors did not have this antibody. There was no strict correlation between the titer of antibody and the severity of jejunal mucosal damage.