Circulating IgA anti-basement membrane antibodies in linear dermatitis herpetiformis (Duhring): immunofluorescence and immunoelectronmicroscopic studies.

IgA deposits were observed by direct immunofluorescence in linear distribution along the basement membrane zone in a case of dermatitis herpetiformis (Duhring). In addition, in the serum of the same patient circulating IgA antibasement membrane zone antibodies were detected by indirect immunofluorescence, utilizing normal human skin and monkey esophagus as substrates. The ultrastructural localization of in vivo-bound IgA and circulating IgA antibasement membrane zone antibodies fixed to substrate tissue in vitro was found to be in the uppermost strata of the dermis below the basal lamina.