RESUMO
Objective: This article investigated the clinical characteristics and distribution of drug resistance mutation sites in HBV RT region of hepatitis B infected patients. Methods: Retrospective analysis was made on 1 948 patients with HBV infection, who had been tested for NAs resistance mutation and had a medical history of NAs in the Laboratory Department of the Fifth Medical Center of the PLA General Hospital from January 2020 to December 2021. Basic clinical information and drug resistance related mutation information were recorded. Meanwhile, the serological index data of hepatitis B were collected. Drug resistance gene mutant group and non-mutated group were grouped according to whether the drug resistance genes had a mutation in HBV RT region, and the clinical characteristics and genotype distribution of the two groups were statistically analyzed. The pattern of drug resistance gene mutation, number of mutation sites, drug resistance type and mutation of NAs resistance-related sites were analyzed in 917 patients with drug resistance gene mutation in HBV RT region. χ2 Inspection was used for counting data. Meanwhile, two independent samples t-test and Wilcoxon rank sum test were used for measurement data. Results: Among the 1 948 patients with chronic HBV infection, 917 patients had drug resistance gene mutation in RT region (47.07%). The proportion of patients with acute hepatitis B and CHB in HBV RT resistance gene mutant group was lower than that in the non-mutated group, while the proportion of patients with HBV-related cirrhosis was higher than that in the non-mutated group, these differences were statistically significant. Compared with the non-mutated group in HBV RT region, the age, the positive rates of HBeAg and HBV DNA, and HBV DNA load of these patients were increased in drug resistance gene mutant group, these differences were statistically significant. Genotypes of patients in both groups were dominated by C, followed by B and D. The proportion of patients with genotype C in HBV RT drug resistance gene mutant group was higher than that of non-mutated group, the difference was statistically significant. There were 53 gene mutation patterns in 917 patients with drug resistance gene mutation in HBV RT region, and the main pattern was rtL180M+rtM204V+rtS202G (9.70%). The mutation sites were dominated by 3 (20.74%). There were 5 types of drug resistance, LAM+Ldt (21.25%) was the most. Among the 18 sites that were clearly associated with LAM, ADV, ETV and Ldt resistance in the HBV RT region, 14 sites were mutated, and the most common mutation sites were rtL180M, rtM204V, rtM204 and rtS202G. what's more, the proportion of patients with NAs drug resistance was LAM>Ldt>ETV>ADV. Conclusion: In order to prevent adverse consequences of this study such as disease recurrence or disease progression caused by HBV drug resistance, HBV infected patients, who have long-term use of NAs antiviral therapy, should monitor the level of HBV DNA and drug resistance genes in HBV RT region in order to optimize the treatment plan in time or guide individualized treatment.