RESUMEN
<p><b>OBJECTIVE</b>To characterize genotypic resistance within HBV RT region in chronic hepatitis B (CHB) patients with nucleos(t)ide analogue (NA) treatment.</p><p><b>METHODS</b>Serum samples of 229 CHB patients with NA treatment were obtained. Full-length HBV RT sequences were amplified, sequenced and analyzed, on the following NA resistant (NAr) mutations belonging to different NAr pathways.</p><p><b>RESULTS</b>Among 229 HBV isolates, 14.41% (33/229) and 85.59% (196/229) were genotype B and C, respectively; and the patients with HBV genotype C may be more susceptible to develope resistant mutations than patients with HBV genotype B(chi2 = 2.95, P < 0.05). NAr mutations were detected in 63 CHB patients. Mutations were not found at rtI169, rtT184, rtA194 or rtS202. RtM204 mutations were detected at the highest frequency among 63 mutants (40/63, 63.49%) and found to display 11 combination mutation patterns, in which rtM204I were associated with rtL80I/V and rtL180M, and rtM204V were associated with rtL1l80M, respectively. Conclusions There are complicated mutation patterns in the HBV RT region for chronic hepatitis B (CHB) patients with nucleos(t)ide analogue (NA) treatment. RtM204V/I mutation was the highest.</p>