EFFECT OF CONCURRENT ACUTE INFECTION WITH HEPATITIS-C VIRUS ON ACUTE HEPATITIS-B VIRUS-INFECTION

Objective-To investigate the possible interference with acute hepatitis B virus infection by coinfection with hepatitis C virus. Design-Analysis of stored sera collected for transfusion transmitted viruses study in 1970s. Setting-Four major medical centres in the United States. Patients-12 recipients of blood infected with hepatitis B virus. Main outcome measures-In 1970s, presence of antibodies in hepatitis B virus and raised serum alanine aminotransferase concentration; detection of antibodies to hepatitis C virus with new enzyme linked immunoassays. Results-Five of the 12 patients were coinfected with hepatitis C virus. Hepatitis B surface antigen was first detected at day 59 in patients infected with hepatitis B virus alone and at day 97 in those coinfected with hepatitis C virus (p=0.01); median durations of antigenaemia were 83 and 21 days respectively (p=0.05), and the antigen concentration was lower in the coinfected patients. Alanine aminotransferase patterns were uniphasic when hepatitis B virus infection occurred alone (range 479-2465 IU/l) and biphasic in patients with combined acute infection (no value >380 IU/l; p=0.0025). Four coinfected recipients developed chronic hepatitis C virus infection. The fifth patient was followed for only four months. Conclusions-Acute coinfection with hepatitis C virus and hepatitis B virus inhibits hepatitis B virus infection in humans, and onset of hepatitis B may reduce the severity of hepatitis C virus infection but not frequency of chronicity. Alanine aminotransferase concentration showed a biphasic pattern in dual infection.