Suppression of hepatitis C virus by hepatitis B virus in coinfected patients at the National University Hospital of Singapore.

This study was carried out to compare hepatitis B virus (HBV) and hepatitis C virus (HCV) replicative states and to determine possible interference between HBV and HCV. One thousand and sixty-one consecutive patients seen at The Gastroenterology Division of the National University Hospital of Singapore between 1988 and 1995 were screened for HBV and HCV serological markers. Anti-HCV was tested using a second-generation enzyme-linked immunosorbent assay (ELISA) method. HCV-RNA was detected by a reverse-transcription polymerase chain reaction method (RT-PCR). Data were analyzed by either paired t-test or chi2 test. Two hundred and twenty-four patients were infected with HBV alone, while 117 patients were infected with HCV only. Thirty-one patients were coinfected with HBV and HCV. HCV-RNA was detected in 104 of the 117 HCV patients (88.9%), and in 12 of 29 coinfected patients (41.4%). Serum anti-HCV levels in the coinfected patients were lower than those in the HCV-infected patients. A significant difference for anti-HCV reactivity and HCV-RNA positivity was observed between HCV-infected patients and coinfected patients (P < 0.01). In contrast, HBV-DNA and hepatitis B envelope antigen (HBeAg) positive rates were similar in HBV carriers and patients coinfected with HBV and HCV. These results show a possible interaction between HBV and HCV life cycles, and suggest that HCV replication may be negatively affected by HBV.