RESUMEN
BACKGROUND/AIMS: Long-term use of nucleos(t)ide analogues (NA) may lead to genotypic and/or phenotypic resistance of the hepatitis B virus (HBV). We investigated the efficacy of tenofovir-based rescue therapy in chronic hepatitis B (CHB) patients with newly developed genotypic resistance to prior NAs or partial virologic response to sequential rescue therapies. METHODS: Fifty-four CHB patients were included retrospectively. The patients were treated with tenofovir alone or combined with lamivudine or entecavir. RESULTS: There were 26 forms of genotypic resistance at enrollment. The median amount of serum HBV-DNA was 18,438 IU/mL and 83% of samples were positive for hepatitis B e antigen (HBeAg). Serum HBV-DNA was undetectable in 50%, 61%, and 76% of the patients at 3, 6, and 12 months, respectively. In multivariate analysis, HBV-DNA < 20,000 IU/mL and negative HBeAg at baseline were independent predictors of negativity for serum HBV-DNA. Interestingly, the rtS202 mutation tended to be associated with an unfavorable response. Other clinical variables and viral resistance genotypes showed non-significant viral response. CONCLUSIONS: Lower serum HBV-DNA, negative HBeAg and lack of rtS202G mutations at baseline may predict a favorable response to tenofovir-based rescue therapies in CHB patients with newly developed genotypic resistance to prior NAs or a partial virologic response to sequential rescue therapies.