Detection of Hepatitis B Virus Polymerase Gene Variants Associated with Lamivudine, Adefovir and Entecavir Resistance and Some Undefined Mutations Isolated from Chronic Hepatitis B Patients in the South of Turkey

Yüksek F. E., Serin M. S., Tezcan Ülger S.

MOLECULAR GENETICS, MICROBIOLOGY AND VIROLOGY, vol.25, no.4, pp.178-182, 2010 (SCI-Expanded)

Abstract

IIn order to detect the mutation patterns related to Lamivudine (LAM), Adefovir (ADV) and Ente

cavir (ETV) resistance, we examined totally 230 stored HBsAg (+) and HBV DNA (+) sera samples of patients suf

fering chronic hepatitis B and treated with LAM, ADV and ETV in the south of Turkey. 100, 110 and 20 sera were

obtained from patients treated with LAM (for at least 2 years), ADV (for at least 2 years) and ETV (for at least

1 year), respectively. A 422 bp segment of HBV polymerase gene which included B, C and D domains of viral poly

merase gene was amplified by a nested PCR protocol and sequenced by a silver staining based cyclesequencing

reaction. Mutation patterns related to LAM, ADV and ETV resistance were detected in 23 of 100 (23.00%), 3 of

110 (2.75 %) and 0 of 20 (0.00%) sera in 3 groups, respectively. rtM204I and rtM204VrtL180M dual mutations

were detected in 13 of 100 (13.00%) and 10 of 100 (10.00%) sera, respectively in LAM treated group. rtN236T

mutation was detected in 3 of 110 (2.75%) sera in ADV treated group. rtM204I and rtM204VrtL180M muta

tions were also detected in 8 of 110 (7.27%) and 5 of 110 (4.54%) sera in ADV treated group. No mutation pat

tern was detected related to ETV resistance. However, rtM204I mutation was also detected in 3 of 20 (15.00%)

in ETV treated group. Additionally, some undefined mutations such as rtI233V, rtN238R, P237H and rtK241E

were detected in 3 of 110 (2.75%), 2 of 110 (1.80%), 1 of 110 (0.90%) and 1 of 110 (0.90%) sera, respectively in

ADV treated group. The study reveals that detection of mutations associated with viral polymerase inhibitors is

important for better patient treatment. Antiviral therapy of hepatitis with viral polymerase inhibitors is still con

troversial.

IIn order to detect the mutation patterns related to Lamivudine (LAM), Adefovir (ADV) and Ente
cavir (ETV) resistance, we examined totally 230 stored HBsAg (+) and HBV DNA (+) sera samples of patients suf
fering chronic hepatitis B and treated with LAM, ADV and ETV in the south of Turkey. 100, 110 and 20 sera were
obtained from patients treated with LAM (for at least 2 years), ADV (for at least 2 years) and ETV (for at least
1 year), respectively. A 422 bp segment of HBV polymerase gene which included B, C and D domains of viral poly
merase gene was amplified by a nested PCR protocol and sequenced by a silver staining based cyclesequencing
reaction. Mutation patterns related to LAM, ADV and ETV resistance were detected in 23 of 100 (23.00%), 3 of
110 (2.75 %) and 0 of 20 (0.00%) sera in 3 groups, respectively. rtM204I and rtM204VrtL180M dual mutations
were detected in 13 of 100 (13.00%) and 10 of 100 (10.00%) sera, respectively in LAM treated group. rtN236T
mutation was detected in 3 of 110 (2.75%) sera in ADV treated group. rtM204I and rtM204VrtL180M muta
tions were also detected in 8 of 110 (7.27%) and 5 of 110 (4.54%) sera in ADV treated group. No mutation pat
tern was detected related to ETV resistance. However, rtM204I mutation was also detected in 3 of 20 (15.00%)
in ETV treated group. Additionally, some undefined mutations such as rtI233V, rtN238R, P237H and rtK241E
were detected in 3 of 110 (2.75%), 2 of 110 (1.80%), 1 of 110 (0.90%) and 1 of 110 (0.90%) sera, respectively in
ADV treated group. The study reveals that detection of mutations associated with viral polymerase inhibitors is
important for better patient treatment. Antiviral therapy of hepatitis with viral polymerase inhibitors is still con
troversial.