A cDNA clone has been derived from the plasma of a chimpanzee with chronic non-A, non-B viral hepatitis (NANBH). We have assayed for antibodies reacting with the encoded antigen in sera from posttrnnsfusion hepatitis patients (643 samples from 23 patients) and their corresponding donors collected during the past 10 years in Japan. The antibody was detected in 15 out of 17 (88.2%) posttransfusion NANBH (PT-NANBH) patients whose sera over time displayed multiple alanine aminotransferase (ALT) peaks. In general, the antibody was detected after several peaks of serum ALT elevations and, once detected, it persisted for years. In contrast to the patients of chronic hepatitis, the antibody was barely detected in patients with a single episode of ALT elevation (1 out of 6). Of the 15 well-dermed cases of PT-NANBH that showed multiple ALT peaks and hepatitis C virus seroconversions, 11(73.3%) were shown to be transfused with at least one unit of blood positive for the antibody. The retrospective analysis showed that all tested donor blood found to be positive for the antibody had been transfused to recipients who afterwards developed NANBH. These data strongly suggest that the cloned cDNA originated from an etiological agent of NANBH termed the hepatitis C virus. Furthermore, the present study demonstrates that had the screening been done with the anti-hepatitis C virus assay, 11 out of 17 (64.7%) cases of chronic PT-NANBH and 1 out of 6 (16.6%) acute PT-NANBH would have been prevented. The antibody assay thus can be used for diagnosis and blood screening for PT-NANBH.Even though donor blood is routinely screened for the hepatitis B virus (HBV) with sensitive assays, about 10% of blood transfusion recipients still develop viral hepatitis (refs. 1 and 2; T.K., unpublished data). Non-A, non-B hepatitis (NANBH) virus(es) is responsible for over 90%o of the posttransfusion hepatitis (PTH) cases and causes a serious health problem throughout the world. NANBH is much more likely to become chronic than HBV-induced hepatitis and often progresses to chronic liver disease, including liver cirrhosis (3, 4). A role for NANBH in the development of hepatocellular carcinoma has also been suggested (5, 6).The genome of a NANBH virus, termed hepatitis C virus (HCV), was cloned recently and shown to contain a positivestranded RNA molecule (7). An assay for circulating viral antibodies was developed by using an HCV antigen purified from recombinant yeast clones to capture reactive antibodies. Results obtained using this assay indicated that HCV is a major cause of transfusion-associated NANBH throughout the world as well as community-acquired NANBH in which no previous parenteral exposure to the virus could be identified (8).In this study, we assayed for HCV antibody in wellpedigreed transfusion-associated NANBH patients in Japan. The serum samples were from patients diagnosed on the basis of clinical presentation in the absence of markers indicating infection with HBV and hepatitis A virus (HAV).-The recipient sera were a series ...

No abstract

Cases of hepatitis virus infection in Japanese recipients of blood transfusions were serologically and clinically analyzed after the introduction of laboratory screening of donor blood for hepatitis B surface antigen by counter immunoelectrophoresis. Non-A, non-B hepatitis occurred in 116 (10.7%) and hepatitis type B in nine (0.9%) of the 1,082 recipients. The incubation period of the post-transfusion non-A, non-B hepatitis cases varied from two to 33 weeks, but most occurred within 15 weeks. In 97 (83.6%) of the 116 cases of non-A, non-B hepatitis studied, the duration of abnormal elevation of the level of serum alanine aminotransferase (glutamic-pyruvic transaminase [SGPT]) was 16 weeks. The cases of non-A, non-B hepatitis could be divided into three groups according to the pattern of elevation of SGPT levels. These findings may suggest either a multiple etiology for non-A, non-B hepatitis or a variety of clinical symptoms with a single etiology for the infection.

The prevalence of both e1 and e2 antigens in 1,158 sera of asymptomatic HBsAg carriers, carriers in hemodialysis units, and HBsAg-negative blood donors was examined. The detection rate of e1 antigen was as high as 80% in asymptomatic carriers, 95% in hemodialysis patients, and even 13.1% in HBsAg-negative donors. All of the e1 antigen-positive specimens in such HBsAg-negative sera were found to have both or either anti-HBs and anti-HBc, suggesting the past history of Hepatitis B virus (HBV) infection of the donors. In the HBsAg-positive serum, the detection rate of e2 antigen (17%) was lower than that of e1 (80%), and all sera having e2 antigen were positive for e1 antigen. The titers of HBsAg, HBcAg, and anti-HBc in e2 antigen-positive sera were higher than that of sera detecting only e1 antigen. The appearance of e1 antigen and e2 antigen in the course of post-transfusion hepatitis B was studied with five cases. Retrospective study showed that three of them each received one unit of HBsAg-positive blood, and the other two received HBsAg-negative blood but with high-titered anti-HBc. In four cases out of five, in which e2 antigen was detected during the course of infection, the initial detection of e2 antigen occurred at or just before the elevation of liver enzyme levels. On the other hand, e1 antigen was detected relatively early after transfusion, and the time of onset. Moreover, the detection period of e1 antigen persisted longer, even after the disappearance of HBsAg antigenemia. These two separate studies suggest that not only e2 antigen but also e1 antigen are associated with the infection of HBV, but they are distinct from each other; the e2 antigen may have the properties of a signal of the viral activity in the patient as suggested by many others, but e1 antigen does not seem to bear such diagnostic values.