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 HCVinfected 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.
Keywords: Occult hepatitis B virus infection (OBI); Chronic hepatitis C virus infection (CHC); Hepatocellular carcinoma (HCC); HBV-DNA; Nested PCR