An Antigen Detected Frequently in Human Sera With Elevated Levels of Alanine Aminotransferase: A Potential Marker For

In a search for additional antigens associated with virus-induced human liver disease a radioimmunoassay (RIA) was developed using IgG from sera of a multiply transfused person. Polystyrene beads coated with IgG F(ab); fragments, F ' dinitrophenylated (ab)2 fragments and a~SI-labelled anti-z,4-dinitrophenyl antibodies (Neurath & Strick, I979) were used in the RIA. An apparently new antigen or the corresponding antibodies were detected in t55 serum specimens from 35/37 (94 %) individuals who developed non-A, non-B hepatitis. The antigen was also present in hepatitis B surface antigen-negative sera of blood donors with normal (13"1%) and elevated levels ofalanine aminotransferase (34%). The antigen has an approximate mol. wt. of 45ooo, a buoyant density of 1.23 g/ml and an iso-electric point of 7