Virus-like antigen, antibody, and antigen-antibody complexes in hepatitis measured by complement fixation.

Complement fixation techniques are described for measuring a virus-like antigen associated with viral hepatitis. Antigen was found in the blood of 98 percent of 130 patients, with the serum form of hepatitis, from whom multiple samples were obtained. Antibodies arising during hepatitis are usually combined with antigen and cause anticomplementary activity in the serum, which is reversible with excess antigen or antibody. Tests for antigen and specific anticomplementary activity can be used diagnostically and to screen blood donors for hepatitis carriers.