摘要
BACKGROUND Whether rtS106C+H126Y+D134E/rtS106C+H126Y+D134E+L269I(rtCYE/rtCYEI)mutations in the hepatitis B virus(HBV)reverse-transcriptase(RT)region are associated with tenofovir disoproxil fumarate(TDF)resistance is controversial.AIM To evaluate the presence of the rtCYE/rtCYEI mutations in a large cohort of Chinese patients with chronic HBV infection.METHODS A total of 28236 patients who underwent drug resistance testing at the Fifth Medical Center of Chinese PLA General Hospital from 2007 to 2019 were enrolled.All patients received nucleoside/nucleotide analogues(NAs)therapy,and serum samples were collected for sequence analysis of the HBV RT domain with mutation analysis.RESULTS The detection rates of a single mutation of rtS106C,rtH126Y,rtD134E,and rtL269I were 8.21%,3.20%,2.55%and 61.49%in 23718 genotype C patients,and 1.31%,1.76%,0.21%,and 92.33%in 4266 genotype B patients,respectively.The combined mutations of rtCYE/rtCYEI were only detected in 12 genotype C patients,accounting for 0.042%of all patients.These 12 patients had received NA treatments except TDF before testing.Among them,6 patients had coexisting rtCYE/rtCYEI and lamivudine-resistance mutations,and 2 patients had coexisting rtCYE/rtCYEI and adefovir-resistance mutations.Compared with the wild-type(WT)strain,the replication capacity of rtCYE/rtCYEI mutants from representative patients decreased by 41.1%-71.8%,and TDF susceptibility reduced by less than 2-fold,but rtCYEI+rtA181V/N236T mutants exhibited a 6.2-/9.9-fold decrease in TDF susceptibility.Molecular modeling showed that rtCYE/rtCYEI mutants had a slight decrease in binding energy to TDF compared to the WT strain.In the clinic,emergence of the rtCYE/rtCYEI mutations was not specifically associated with TDF treatment.CONCLUSION HBV rtCYE/rtCYEI mutations have a limited effect on TDF susceptibility and are not sufficient to cause TDF resistance.
基金
Supported by The National Natural Science Foundation of China,No.82470632.
