Hepatitis C virus as a cause of transfusion-related hepatitis
Non-A, non-B hepatitis remains the most common serious consequence of blood transfusion. The recent cloning and sequencing of the non-A, non-B virus (now designated the hepatitis C virus) and the development of a serologic assay to detect hepatitis C virus antibody have been breakthroughs in the search for the causative agent of non-A, non-B hepatitis. An estimated 150 000 cases of non-A, non-B hepatitis occur in the United States each year. Several recent studies have encouraging implications for the treatment and prevention of new infections.
Alter and colleagues identified antibody to the hepatitis C virus (anti-HCV) in transfusion recipients who developed non-A, non-B hepatitis. Anti-HCV was also present in donors. The authors believe that hepatitis C virus is the predominant agent of transfusion-associated non-A, non-B hepatitis and that screening of donors for anti-HCV will substantially decrease the incidence of post-transfusion hepatitis.
Chronic liver disease develops in about half of all patients with acute non-A, non-B hepatitis. Approximately 20 percent of these patients subsequently develop cirrhosis. Davis and colleagues and Bisceglie and co-workers report the results of two different multicenter trials that demonstrated the efficacy of recombinant interferon alfa in the treatment of chronic hepatitis C virus infection. In each study, interferon therapy was followed by improved or normal serum aminotransferase values and marked improvement in the histologic features of the disease in approximately half of the treated patients. However, relapse occurred in most of the study patients after interferon therapy was discontinued. The long-term effects of interferon therapy on viral replication, infectivity and the natural history of hepatitis C virus remain unknown.
In a related editorial, Alter and Sampliner note that while anti-HCV screening may dramatically reduce the risk of hepatitis acquired through blood transfusion, only 5 to 10 percent of the annual cases of hepatitis C virus infection result from blood transfusions. At least 40 percent of patients with hepatitis C virus infection report intravenous drug use, while an additional 40 percent have no known source of infection. (New England Journal of Medicine, November 30, 1989, vol. 321, pp. 1494, 1501, 1506 and 1538.)
COPYRIGHT 1990 American Academy of Family Physicians
COPYRIGHT 2008 Gale, Cengage Learning