Detection of an antigen-antibody system in serum associated with human non-A, non-B hepatitis

An antigen was detected by counterelectrophoresis in serum samples from six of seven chimpanzees during the acute phase of experimentally induced non-A, non-B hepatitis using antiserum from a chimpanzee convalescent from human non-A, non-B hepatitis. This antigen could not be detected in 35 preinoculation serum samples from these chimpanzees, or in 94 weekly bleedings from three chimpanzees with hepatitis A and three chimpanzees with hepatitis B. The antigen was detected in serum samples obtained from three humans with chronic non-A, non-B hepatitis whose blood had transmitted non-A, non-B hepatitis to other humans (including a nurse by accidental needlestick) and to chimpanzees by experimental inoculation. In addition, the antigen was detected in serum obtained retrospectively from 11 to 31 former blood donors whose blood had transmitted posttransfusion non-A, non-B hepatitis several years previously to recipients of a single unit of their blood. Antibody to this antigen was detected in convalescent serum samples from all seven chimpanzees studied, in convalescent serum from the nurse infected by accidental needlestick, and in serum from a hemodialysis patient convalescent from non-A, non-B hepatitis.