Immunologic phenomena in herpes gestationis.

Immunofluorescence findings are of diagnostic significance in herpes gestationis. The studies in two cases demonstrated some complement components (chiefly C3 and C4, but no C(1q)), without immunoglobulins at the basement membrane zone and with no circulating anti BMZ antibodies. In one case IgG were found at the BM zone in one biopsy specimen, but were not demonstrable in several other biopsies. The IF findings seem to indicate both the alternate and classical pathways of complement activation, and speak in favor of a relation between herpes gestationis and bullous pemphigoid, in which sometimes the immunoglobulins are also not demonstrable and the immunofluorescent pattern is very much like that of herpes gestationis.