The Relationship Between The HBV C Gene Mutation And The Celluar Immunity Of The Host

Objective: To study the relationship between the HBV DN'A C gene mutations and the cellular immunity of patients with chronic hepatitis B..Methods: HBV DNA C gene mutations were confirmed by polymerase chainreaction (PCR) and sequenced the products directly; The cytokines (IFN-Yx TNF-a and IL-2) levels in serum were measured by enzyme linkedimmunosorbent assay ( ELISA ) ; The distributions of T-lymphocytesubpopulations in peripheral blood were detected by Flow Cytometry(FCM) .Results: The mutations within HBV C gene were popular in 91 patients with chronic hepatitis B, especially concentrated in HBV precore 1896 site and epitopes in C gene recognized by cytotoxic T lymphocyte (CTL) ; The mutation of A1896 was more common in chronic fulminant hepatitis, the levels of IFN- Y and TNF-a and the radio of CD*4/CD8* were higher, and the percentage of CD8*T lymphocyte was lower in mutate group than wild strain group(P < 0. 05) ; The infective rate of mutation in aal8-27 was much higher in group of chronic hepati ti s (mide) , followed by lower concentration of IFN-Y and TNF-a in mutate group than wild strain group(P < 0.05); The levels of IFN-Y and TNF-a and the radio of CD*4/CD8'were higher, the percentage of CDS'T lymphocyte was lowor in3mutate groups of aa48-60 and aa84-101 than wild strain group, especially L97 (Lie substituted by Leu) and V60 (Lie substituted by Val) mutate groups were significant differences from wild strain groups; There was no apparently difference between the mutate groups in aa!41-151 and the wild strain group.Conclusion: In chronic hepatits B, the infective rate of HBV DNA C gene mutate-type is high, and the mutation in difference domain showed different relationship between mutation and cellular immunity; The mutation of A1896 was strongly related with the severe damage of hepatocyte and abnormal cellular immunity; The mutation of aal8-27 may escape the recognization of CTL and made the infection persistent; Mutation in aa48-60 and aa84-101 especially L97 and V60 were remarkable related with severe hepatitis and abnormal of cellular immunity, which indicate these two mutations maybe increase the affinity with HLA-I molecule, or upregulate the expression of HLA-I molecule; There was no obviously correlation between aa!41-151 mutation and the level of cellular immunity. So, combined examination of mutation of HBV C gene, the concentration of cytokines and T lymphocyte subpopulations is very significant to real ise the relationship between HBV C gene mutation and the cellular immunity of the host, and also can offer the basis to further announce the pathogenesis of chronic hepatitis B and individual diagnosis and treament.