The nature and incidence of cryoproteins in hepatitis B antigen (HbsAg) positive patients.

Hepatitis B (HbsAg) surface antigen has been detected in the serum of patients with a variety of diseases and immune complexes of this antigen and antibody have been implicated in tissue damage to various organs. Previously we have demonstrated that serum cryoproteins occur in a variety of immune complex disorders and represent pathogenic complexes of antigen and specific antibody. Sera from patients with acute HbsAg positive hepatitis, chronic hepatitis B antigenemia, acute and chronic HbsAg negative hepatitis, as well as a variety HbsAg negative miscellaneous liver diseases and normals were studied for the presence and nature of cryoproteins. Cryoproteins were detected in a large number of patients with acute and chronic HbsAg positive hepatitis and chronic HbsAg carriers. The quantity of these cold insoluble precipitates was highest in acute hepatitis. Cryoproteins were detected with much less frequency in HbsAg negative patients and were not found in normals. The precipitates in HbsAg patients contained either HbsAg, anti-HBsAg or both, along with immunoglobulins and occasionally complement and rheumatoid factor. The cryoproteins in these patients had biological properties attributable to immune complexes and several of the patients had clinical manifestations of acute or chronic serum sickness. Cryoproteins from HbsAg negative patients did not contain HbsAg or antibody to HbsAg and did not have biologic properties of immune complexes. In HbsAg positive patients HbsAg and antibody to HbsAg were concentrated in the cryoprecipitate. The preliminary studies suggest that investigation on cryoproteins in hepatitis may be of clinical and immunopathogenic value.