Hepatitis B virus genotyping among chronic hepatitis B patients with resistance to treatment with lamivudine in the City of Ribeirão Preto, State of São Paulo

Abstract

Introduction: Lamivudine is a nucleoside analogue that is used clinically for treating chronic hepatitis B infection. However, the main problem with prolonged use of lamivudine is the development of viral resistance to the treatment. Mutations in the YMDD motif of the hepatitis B virus DNA polymerase gene have been associated with resistance to drug therapy. So far, there have not been many studies in Brazil reporting on genotype-dependent development of resistance to lamivudine. Thus, the aim of the present study was to determine the possible correlation between a certain genotype and increased development of resistance to lamivudine among chronic hepatitis B patients. Methods: HBV DNA in samples from 50 patients under lamivudine treatment was amplified by means of conventional PCR. Samples were collected at Hospital das Clínicas, FMRP-USP. The products were then sequenced and phylogenetic analysis was performed. Results: Phylogenetic analysis revealed that 29 (58%) patients were infected with genotype D, 20 (40%) with genotype A and one (2%) with genotype F. Mutations in the YMDD motif occurred in 20% of the patients with genotype A and 27.6% of the patients with genotype D. Conclusions: Despite the small number of samples, our results indicated that mutations in the YMDD motif were 1.38 times more frequent in genotype D than in genotype A.

Melting Curve Analysis for the Screening of Hepatitis B Virus Genotypes A, D and F in Patients From a General Hospital in Southern Brazil

“…Genotype F was found in only 5% of the population investigated. Similar results were reported in Brazil by Haddad and also by a previous study of our group (2,13) . The distribution of genotypes in the Brazilian population correlates with the origin of our ancestors.…”

Genotyping of HBV and tracking of resistance mutations in treatment-naïve patients with chronic hepatitis B

“…The ALT serum levels showed no influence on the emergence of antiviral resistance mutations 44. In Brazil, there are few studies that were conducted on survey resistance mutations to NA on naïve patients seeking clinical association 45–47. However, other studies should be conducted to track and trace the changes in the mutation profile, crossing with the epidemiological characteristics of the population, with a larger number of treatment-naïve patients with CHB.…”

Detection of lamivudine-resistant variants and mutations related to reduced antigenicity of HBsAg in individuals from the cities of Santos and São Paulo, Brazil

“…However, among chronically infected and treated Brazilian individuals, the rate of LAM resistance (rtM204V + rtL180M) ranges from 16% to 41% [17,18]. Regarding HBV/HIV co-infected and treated individuals, the mutation rate ranges from 21.42% to 45.45% [19-21].…”