Immunologic phenomena in herpes gestationis

Immunopathological studies in herpes gestationis

Four cases of herpes gestationis are reported and the immunopathological findings in these patients described. Complement deposition at the basement membrane zone of the patients' peri-bullous skin was seen in all patients, immunoglobulin deposition in two. A circulating factor capable of fixing complement on the basement membrane zone of normal human skin was present in three patients. These findings are discussed and compared with the immunopathological findings in bullous pemphigoid.

Herpes gestationis: fine structural pattern of immunoglobulin deposits in the skin in vivo

IgG and C3 deposits were observed in the basement membrane zone in a case with herpes gestationis. In addition, circulating IgG anti-basement membrane antibodies were found. Electron microscopic immunocytochemical investigations, performed with a peroxidase-antiperoxidase sandwich technique, revealed the in vivo-bound IgG to be localized at the epidermal basal lamina and to exhibit a distribution pattern which is identical to that reported for bullous pemphigoid.

Herpes gestationis. Ultrastructure and ultrastructural localization of in vivo-bound complement

Ultrastructural localization of C3 deposition in the skin of two patients with herpes gestationis was determined by using a peroxidase-antiperoxidase multistep technique. The tissue preparations can be stored for long periods of time and identical sections may be used for light and electron microscopic examination. The reaction products were seen throughout the entire lamina lucida and the basal cell plasma membrane appeared to be accentuated. The most remarkable ultrastructural changes in normal-appearing skin were the destruction of the basal cell membranes on the dermal side, localized cytoplasmic dissolution, and intracellular edema unaccompanied by inflammatory cells. Early, nonvesicular lesions showed basal cell degeneration and dermal inflammatory cells. Necrosis and loss of basal cells occurred in the next stage which resulted in microvesicles in which collagen or a well-preserved basal lamina formed the vesicle base. In the later blister stage, the basal lamina was usually lost. It is suggested that damage of basal cell membranes on their dermal side leads to the destruction of basal cells with the subsequent protrusion of epidermal and junctional substances into the dermis. This may result in inflammatory cell infiltration and blister formation.

Herpes gestationis. Immunopathology and characterization of the HG factor

Five patients with herpes gestationis, a blistering disease of pregnancy, were studied immunologically. All had in vivo deposition of C3 in a linear band along the basement membrane zone of lesional and normal-appearing skin, the location of early blister formation. Immunoglobulin deposition was more variable, though four patients had evidence of in vivo bound IgG at the same site. A circulating, complement binding herpes gestationis factor was demonstrated in the sera of four of the patients, its concentration unrelated to the activity of clinical disease. Characterization of this factor by sucrose gradient ultracentrifugation, specific absorption studies, and papain digestion indicates that it is an IgG. Evidence exists for involvement of both the classical and alternate complement pathways in vivo, though in vitro studies implicate the classical pathway as the primary route of complement activation. Three offspring were studied, none with clinical involvement; one showed in vivo deposition of C3 at the basement membrane zone of normal skin and a second showed the herpes gestationis factor in cord blood.