Cryoglobulins in acute and chronic liver diseases.

Cryoglobulins were detected in the sera of thirteen patients with acute viral hepatitis and of twelve with chronic hepatic diseases (active chronic hepatitis, primary biliary cirrhosis and cryptogenic cirrhosis). Their nature and antibody activity was studied. In both groups, most of them consisted of mixed cryoimmunoglobulins (IgM, IgG and/or IgA), but some were single-class immunoglobulins with one or both types of light chains. Unusual components were also found. α1-fetoprotein was present in four cryoprecipitates: in two as the single constituent and in two associated to immunoglobulins; hepatitis-associated antigen co-existed in one of the latter. Some cryoglobulins showed antibody activity against human IgG, smooth muscle and mitochondrial antigens. In one case, the IgM-kappa of the cryoprecipitate had antibody activity against α1-fetoprotein; this antigen was also present in the cryoprecipitate, suggesting immune-complex formation. Autoantibodies were also looked for in the sera of the twenty-five patients; apart from the most common ones, antibodies to α1-fetoprotein were found in two patients.