Lamivudine and Adefovir Motif Variants Detected in chronic Hepatıtıs B patients

Abstract

Background and aims: Chronic hepatitis B is an important health problem worldwide. Lamivudine, adefovir, entecavir and telbivudine are the oral drugs licensed for the treatment of patients with chronic hepatitis B. Implementation of antiviral therapy leads to the emergence of mutant strains during the treatment in chronic hepatitis B. Primary antiviral resistance may be rarely encountered. The aims of this study were to detect the resistance patterns of Hepatit B Virus strains in treatment-naive chronic hepatitis B patients.

Materials and methods: A total of 147 CHB patients were included to this study which was carried on between January 2007- December 2010. HBV DNA levels were detected by using the Real time PCR (COBAS Ampli- Prep/COBAS TaqMan HBV Test). HBV-DNA was extracted from the sera of the patients by using extraction kit (Invisorb, Instant Spin DNA/RNA Virus Mini Kit, Germany). A line prob assay (Inno-Lipa HBV DR v2, Innogenetics N.V, Ghent, Belgium) was used to determine motif variants at viral polymerase gene fragment in HBV-DNA samples of these patients and evaluated colorimetrically.

Results: In 147 patients antiviral resistance rate was found 17% (25/147) for lamivudin, 5.44% (8/147) adefovir, 0.68%(1/147) lamivudin and adefovir. Various mutations were detected. This mutations; responsible for lamivudine resistance YMDD+YVDD (n=10), YMDD+YIDD (n=12), YIDD (n=2), YVDD (=1); responsible for adefovir resistance N236T (n=3), A181T (n=5); responsible for lamivudine and adefovir resistance YMDD+YIDD+N236T (n=1).

Conclusions: As a conclusion, it is thought that drug resistance should be followed up regularly, the determination of HBV drug resistance as immediate as possible period may be instructive for the treatment and follow-up in CHB patients. Although determination of known mutations with Inno Lipa DR v2 method is disadvantage, because of ease of application and the determination of both lamivudin-adefovir resistance in a short time, it can be used for the treatment and follow-up in CHB patients.