Serum HBV DNA detected by PCR in dot blot negative HBV chronic carriers with active liver disease.

A group of forty-nine HBV chronic carriers with histologically confirmed active liver disease and undetected serum HBV DNA by dot-blot hybridisation were re-investigated using the polymerase chain reaction (PCR) for amplification of serum DNA. The group comprised 16 persistently serum HBeAg-negative and thirty-three anti-HBe-positive patients. The use of PCR followed by Southern blot analysis has increased the sensitivity of HBV DNA detection to about 10-50 virions per ml of serum. Our results showed 14/16 (87.5%) of the HBeAg-positive group and 27/33 (81.8%) of the anti-HBe group to be positive for HBV DNA using PCR. Of the nine cases where HBV DNA was undetected four were positive for markers of hepatitis delta virus (HDV) infection. Demonstration of low level HBV replication associated with active liver disease in chronic HBV carriers where it was previously undetected meets a basic requirement for the proposed role of cytotoxic T lymphocyte-mediated immunopathogenesis in chronic hepatitis B and suggests a combined antiviral and immunotherapeutic approach to achieve eradication of the infection.