Circulating IgA anti-basement membrane zone antibodies in dermatitis herpetiformis.

Criculating anti-basement membrane zone antibodies of the IgA class were detected in the sera of 2 or 6 dermatitis herpetiformis (DH) patients who had linear in-vivo-bound IgA deposits and in 1 of 42 DH patients who had granular vivo-bound IgA deposits. In the former 2 patients the circulating antibodies were localized ultrastructurally to the identical site where the in vivo-bound antibodies were localized and were bound by antigens in either the lamina lucida or the subbasal lamina anchoring fibril area of the basement membrane zone of normal human skin.