Crystallocryoglobulinemia Resulting from Human Monoclonal Antibodies to Albumin

Abstract

Two patients has a previously unrecognized form of crystallocryoglobulinemia. Their clinical presentations were similar, consisting of necrotizing vasculitis and purpura involving the legs. Analysis of each cryoglobulin complex showed that 2 components, albumin and a monoclonal IgG-.lambda., were present, and both components were needed in a fixed ratio for precipitation. Cryoprecipitation occurred in serum, but not plasma, due to citrate inhibition of complex formation. The monoclonal IgG possibly have the properties of antibodies directed specifically against a Ca-dependent antigenic site on human albumin, and the resultant IgG-albumin immune complexes may have crystallized in the cold.