Detection of occult HBV infection by nested PCR assay among chronic hepatitis C patients with and without hepatocellular carcinoma

Occult hepatitis B virus infection (OBI) has been reported among patients with chronic hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). This study aimed to evaluate the prevalence of OBI in chronic hepatitis C patients with and without hepatocellular carcinoma. A total of 40 chronic hepatitis C patients who were negative for HBsAg, were enrolled into the study. They were classified into two groups: Group I which included 20 patients with chronic hepatitis C only whereas Group II included 20 patients with chronic hepatitis C and HCC. Detection of HBV DNA was done by nested-PCR using two sets of primers specific for surface and X viral genomes in serum and liver tissue of patients. Genotyping system based on PCR using type-specific primers was done for HBV-DNA positive intrahepatic samples. OBI was detected in the liver tissue in 23/40 (57.5%) of chronic HCV infected patients, 18 (78.3%) of whom belonged to group II, conferring a 90% prevalence of this group. In serum, HBV-DNA was detected in 9/40 patients (22.5%), 7 (77.8%) of whom belonged to group II. Among the 23 positive intrahepatic HBV-DNA samples studied, HBV-genotype D (34.8%) and B (26.1%) were more predominant, whereas HBV-genotype C (13.1%) and A (8.7%) infections were the least observed, respectively; mixed genotypes were detected in 17.4% (n = 4), 3 of them were with HBV-genotype D and B, and 1 was with HBV-genotype C and A.In conclusion OBI is a fact in our community; it was detected in liver tissue of chronic HCV-infected patients, especially in cases of chronic HCC. In addition, OBI might be related to severity of necroinflammatory activity and fibrosis. Large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population. Also, detection of intrahepatic HBV-DNA is more useful in diagnosis of OBI.