Characterization of cryoprecipitates in pemphigus: demonstration of pemphigus antibody activity in cryoprecipitates using the immunofluorescent technique.

Cryoproteins observed in patients with pemphigus have been shown to contain IgG, complement components, and other serum proteins. The IgG moiety possessed pemphigus antibody activity and contained kappa and lambda light chains. Cryoproteins appeared in the clinically active stage and disappeared subsequent to clinical improvement. These observations indicate that immune complexes may exist in the sera of patients with pemphigus.