ANNALS OF CLINICAL AND ANALYTICAL MEDICINE, sa.3, ss.182-187, 2024 (ESCI)
Aim: The prevalence and clinical effects of mutations in the reverse transcriptase (RT) region of the Hepatitis B Virus (HBV) before antiviral treatment in patients with chronic Hepatitis B (CHB) are not clear. In this study, the aim was to investigate the prevalence, characteristics, antiviral drug resistance, and clinical effects of mutations in the RT region of the HBV polymerase gene in patients with treatment -naive CHB. Material and Methods: The study included 102 treatment -naive patients who underwent liver biopsy due to chronic hepatitis B disease. The gene region encoding HBV RT enzyme was amplified by PCR and Sanger sequencing was performed. Results: The genotype of all patients with CHB was defined as HBV/D. In the study, among the 102 included patients, 82 (80.39%) had a total of 35 types of mutations associated with the 42 previously identified Nucleos(t)ide analogs (NAs) resistance (NAr) mutation positions in the HBV RT region. In a total of 5 patients (4.90%), primary and secondary drug resistance were detected. In this study, 22 new mutations were identified in 13 out of 31 RT positions associated with NAr. No statistically significant differences were observed in terms of liver enzymes and histologies, as well as virological features including HBV DNA levels, between patients with detected NAr mutations and those without. Discussion: Although the prevalence of amino acid (AA) variations in the HBV RT region is high in patients with HBV/D genotype, primary and secondary antiviral resistance associated with NAs is rare. Effects of NAr mutations on the progression of HBV-related diseases are also quite limited.