Abstract
Background Occult hepatitis B virus infection (OBI) frequently occurs in patients with chronic hepatitis C (CHC) infection, but the influence of OBI on CHC outcome is still uncertain. The aim of the present study was to clarify the clinical and pathological characteristics of OBI in CHC-related hepatocellular carcinoma (HCC). Patients and methods DNA was obtained from serum and tumor tissue of patients with hepatitis C virus (HCV)-related HCC with negative HBsAg and from patients with HCV-related liver cirrhosis. HBV-DNA was detected using qPCR. Clinicopathological features were compared between patients with HCC with and without OBI. Results On the basis of positive serum and tissue HBV-DNA typing, the overall frequency of OBI was 50% in patients with HCV-related HCC. HBV genotype D was the most dominant, constituting 35.3% of HCC cases. Almost 80% of patients with OBI had anti-HBc, whereas 20% of patients had no serological markers. Tissue HBV-DNA showed significant association with positive serum HBV-DNA, anti-HBc, and genotype D. There were no clinical differences between patients with HCC with and without OBI; however, patients with OBI tended to be younger. HCC cases with positive OBI were significantly associated with positive anti-HBc antibodies and late histological grades (3-4). Multivariate logistic regression analysis revealed that the presence of OBI was a predictor of more advanced HCC histological grades in patients with HCV infection. Conclusion OBI was detected in 50% of HCV-infected patients with HCC. OBI was strongly associated with the presence of anti-HBc antibodies. Patients with HCC with positive OBI were younger and had more advanced HCC histological grades.