Comparison of in vivo and in vitro capability of complement fixation by pemphigus antibodies.

Using complement immunofluorescence, the capability of complement fixation by bound antibodies in pemphigus lesional skin was compared with circulating intercellular antibodies of complement-fixing type in the same patient. Five lesional skin samples from 6 patients, containing bound IgG, gave positive binding of complement (C3) supplied from fresh guinea pig serum, while only one serum sample showed complement-fixing pemphigus antibodies in the circulation. These results support the view that complement-fixing pemphigus antibodies are rapidly localized to the skin and play a role on the production of acantholysis.