Real-time quantification of hepatitis B virus core-promoter and pre-core mutants during hepatitis E antigen seroconversion

Background/Aims: Detection of hepatitis B virus (HBV) core-promoter A(1762)T-G(1764)A and pre-core G(1896)A mutants has relied on qualitative assays. We tested the hypothesis that the quantity of A(1762)T-G(1764)A and G(1896)A mutants might have clinical impact, by quantifying these mutants before and after HBe antigen (HBeAg) seroconversion in 58 patients. Methods: A real-time quantitative-polymerase chain reaction (Q-PCR) was developed, using minor groove binder (MGB)-conjugated TaqMan probes to impart reaction specificity for wildtype/mutant HBV populations. Results: Significant quantities (>20%) of core-promoter A(1762)T-G(1764)A mutant existed in 65% of patients before and after HBeAg seroconversion, and were significantly changed (>20% increase/decrease) in 13% of patients after seroconversion. Quantity of A(1762)T-G(1764)A Mutants was positively correlated with alanine aminotransferase (ALT) (P < 0.001) and HBV DNA (P < 0.001) levels, both before and after HBeAg seroconversion. Significant quantities of pre-core G(1896)A mutant existed in about 90% or patients before and after HBeAg seroconversion, and were changed in 16% of patients after seroconversion. Quantity of G(1896)A mutant was negatively correlated with ALT (P = 0.044) and HBV DNA (P = 0.007) levels. Conclusions: The A(1762)T-G(1764)A and G(1896)A mutants existed in a high proportion of patients before and were unaffected after HbeAg seroconversion. The quantities of A(1762)T-G(1764)A mutant were positively and G1896A mutant negatively correlated with liver inflammation and viral replication. (C) 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.