Real-time quantification of hepatitis B virus core-promoter and pre-core mutants during hepatitis E antigen seroconversion.
OBJECTIVE
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% of 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 G(1896)A mutant negatively correlated with liver inflammation and viral replication.
Pang
Annie
A
University Department of Medicine, Queen Mary Hospital, Professorial Block, Pokfulam Road, Hong Kong, China.
Yuen
Man-Fung
MF
Yuan
He-Jun
HJ
Lai
Ching-Lung
CL
Kwong
Yok-Lam
YL
D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D006514:Hepatitis B Surface Antigens; D006515:Hepatitis B virus / Q000235:genetics*; D016751:Hepatitis E / Q000276:immunology*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D009154:Mutation; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014758:Viral Core Proteins / Q000235:genetics
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D009838:Oligodeoxyribonucleotides; D014758:Viral Core Proteins