The characterization and clinical significance of quasispecies in the reverse transcriptase region of hepatitis B virus in hepatitis B virus infected patients with different disease stages / 中华传染病杂志

ABSTRACT

Objective To characterize the profile and clinical significance of hepatitis B virus (HBV) quasispecies in patients infected with hepatitis B virus based on the sequence of reverse transcriptase (RT) region.Methods Fifty HBV infected treatment-naive patients were enrolled and divided into three groups,asymptomatic carriers (ASC) group (10 cases),chronic hepatitis B (CHB) group (30 cases) and liver cirrhosis (LC) group (10 cases).HBV genomes were extracted from serum samples.The sequence of RT region was amplified by polymerase chain reaction (PCR) and cloned into vectors.Fifteen to thirty clones per sample were selected,sequenced and analyzed by bioinformatics software.The mean values among groups were compared by analysis of variance.The median values among groups were compared by nonparametric statistics.The enumeration data were analyzed by x2 test.Results Totally 1221 HBV RT region nucleotide sequences were obtained (152from ASC patients,780 from CHB patients and 289 from LC patients).Genotype distribution showed no difference among three groups.However,the quasispecies complexity showed significant differences among the three groups,LC group ＞CHB group＞ ASC group (F=33.400,P＜0.05).The quasispecies diversity was LC group ＞CHB group＞ ASC group,and that of LC group was significantly different from the other two groups (F=18.070,P＜0.05),while there was no significant difference between CHB and ASC patients.Conclusions The HBV isolated from patients in immune clearance phase have higher variability than those isolated from patients in immune tolerance phase.The longer the infection persists and the more severe the disease is,the more variable HBV quasispecies are.