Detection of occult hepatitis B virus among chronic hepatitis C patients
Background: Concurrent infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are increasingly recognized in patients with chronic hepatitis. In Egypt, the last decade showed a remarkable decline in HBV infection associated with remarkable rise in HCV infection. The probable impact of occult HBV in patients with chronic HCV infection has been previously investigated and the evidence suggests a possible correlation with lower response to anti-viral treatment, higher grades of liver histological changes, and development of hepatocellular carcinoma. The aim of this study was to analyze the possible influence of occult HBV infection on the clinical outcomes in chronic HCV patients and to compare conventional and real-time PCR in detecting HBV DNA among Hepatitis B surface antigen (HBsAg) negative chronic HCV.
Methods: Sera collected from 100 chronic HCV patients (negative for HBsAg and positive for anti- HCV and HCV RNA) were tested for anti-HBc, anti-HBe and anti-HBs by ELISA, HCV-RNA viral load was determined by real-time PCR (TaqMan probe technique) and HBV DNA was detected with primers encoding the surface (S), core (C), polymerase (pol) and X genes. In addition, determination of liver enzymes including aspartate and alanine aminotransferases (AST, ALT) activities was performed.
Results: Fifty-eight percent of the study group were positive for anti-HBc. Meanwhile, only 18 cases (18%) were positive for the polymerase gene by nested PCR and were considered as occult HBV. Among these 18 polymerase gene positive patients (occult HBV) anti-HBc was detected among 9 (50%) of cases. Different gene profiles were noticed among the 18 polymerase gene positive patients.
Keywords: Chronic hepatitis C; Occult hepatitis B virus; Real-time PCR; SYBR Green; Conventional PCR; HBV pol gene