Multilocus drug resistance mutation analysis in 148 HBV patients in northern Henan Province of China

Objectives: To analyze the genotypes and reverse transcriptase mutations gene sites in hepatitis B (HBV) patients in northern Henan Province from 2016 to 2018, which treated by tenofovir dipivoxil(TDF), Lbivudine(LDT), adefovir(ADV), lamivudine (LAM) and entecavir(ETV) analogues, to provide evidences for rational drug use and antiviral therapy for HBV patients. Methods: HBV patients serum DNA was extracted, specific primers were designed for YMDD mutation sites in conservative regions; DNA sequencing of the PCR products was carried out by PCR amplification combined with Dideoxygenation termination sequencing(DDT), and then analyzed genotype and reverse transcriptase mutations gene sites of HBV patients. Results: We collected 148 samples of HBV patients in northern Henan Province from 2016 to 2018; 97.97% of HBV patients were genotype C and 2.03% were genotype B; there are 46 cases of LAM and FTC resistance mutation, respectively; 28 cases of LDT resistance mutation, 10 cases of ADV resistance mutation, 8 cases of ETV resistance mutation, and 1 case of TDF resistance mutation were detected; the mutation rates of drug resistance was 43.45% in HBV patients with genotype C and 33.33% in HBV patients with genotype B. There was no significant difference in the distribution rate between the two genotypes (P>0.05). The most common mutations types were M204M|V and M204M|I. The M204M|V mutation type often occurred in combination of M204M|V+L180M|L+L173V|L and M204M|V+L180M|L and M204M|V+ L180M|L+V173V|M, while M204M|I mutation type was often occurred alone, M204M|V+L180M|L combination appeared alone or in combination. N236+A181 base substitution was the dominant site in ADV resistance. ETV resistance mutation was based on LAM and ETV resistance, mainly were T184 and S202 base substitution; and LDT resistance mutation was M204M|I. Conclusion: In this article, PCR and DDT DNA sequencing were used to detect multisite resistance mutations of HBV reverse transcriptase gene in HBV patients. It was found that most of the genotypes of HBV patients in northern Henan Province were genotype C, the combination of drug resistance mutations was complex, and the mutation rates of multidrug resistance genes was high. There was no significant difference in the distribution rate of HBV genotypes among the detected patients, those data may provide evidences for the detection and confirmation of HBV resistance and rational drug use in HBV patients in the region.