Dermatitis herpetiformis bodies. Ultrastructural study on the skin of patients using direct preembedding immunogold labeling.

Skin samples from three adult patients with dermatitis herpetiformis (DH) and granular IgA deposits in the papillary tips were studied using ultrastructural immunogold technique. IgA positive, so-called DH bodies were identified as amorphous clumps--most probably immunocomplex aggregates--scattered throughout the upper papillary dermis. Dermatitis herpetiformis bodies were seen underneath the basement membrane, sometimes along microfibrillar bundles, as well as adjacent to the papillary collagen fibers and within the surface (microfibrillar) region of elastic tissue. Some DH bodies, however, were not related to any fibrillar components. The collagen and elastic fibers, microfibrillar bundles, anchoring fibrils, and elastic microfibrils themselves were unlabeled. Dermatitis herpetiformis bodies were not found in normal human skin. The results of our ultrastructural study indicate that DH bodies either are bound to a nonfibrillar component of dermal connective tissue or represent deposits of immune complexes trapped in DH skin.