Evaluation of the pol/S Gene Overlapping Mutations in Chronic Hepatitis B Patients in Northern Cyprus

Abstract

Mutations associated with the pol and the S gene can emerge as a consequence of the high replication capacity and proofreading deficiencies of hepatitis B virus during replication. The current study was constructed to evaluate primary, partial, compensatory and the escape mutations in chronic hepatitis B patients in Northern Cyprus. The samples of HBsAg positive treatment naïve 100 patients were involved in this study. HBV pol gene region was sequenced, amplified and HBV pol/S gene mutations were determined. The samples of thirty-two patients were excluded because of their low viral load (HBV < 1000 ıu/ml). Among the sequenced 68 samples, there was a partial mutation (1.5%) and 36.7% displayed a resistance profile to lamivudine, adevofir, and telbivudine. Immune response escape, vaccine escape, HBIg and diagnosis escape mutations were determined in 24%, 10%, 6%, and 4% samples of the patients, respectively. Additionally, there were six different combined mutations. These data underscored that there is no concern for primary mutations in Northern Cyprus, however, we have identified a compensatory mutation (rtV173M) that may have primary mutation characteristics by combining with other mutation patterns. Additionally, HBsAg escape mutants demonstrated that detection of the S gene together with the pol gene mutations might be beneficial and important to monitor the surveillance of S variants.

Detection of Hepatitis B Virus (HBV) Genotypes by Nested Polymerase Chain Reaction (PCR) Technique in Diyala Province

“…Similar results were obtained by Al-Mhanah and Abood [21] found from 80 patients infected only 33 samples (41.25%) were positive for PCR. In Iran from (150) infected patients only 28(18.7%) samples were positive [22] while, in Turkey from (170) infected patients only 108(63.5%) samples were positive [23]. The Nested PCR products after amplification using specific primers have been presented to the gel electrophoresis, which showed the bands, as shown in the figures ( 1) and ( 2).…”

Profile of Biochemical Markers and Viral Load in a Population of Blood Donors Infected with Hepatitis B and Naive Antiretroviral Treatment in Abidjan

“…The hepatitis B virus (HBV) is a DNA virus of the Hepadnavirus family that infects the liver and causes Hepatitis B [1]. After an acute phase, some hepatitis B cures spontaneously while others become chronic [2]. Indeed, if not diagnosed and treated, hepatitis B can progress to cirrhosis or even hepatocellular carcinoma [3,4].…”

Hepatitis B Virus: From Diagnosis to Treatment

“…Although it is known as a virus with high replication ability, due to the absence of the proofreading reverse transcriptase enzyme, the naturally occurring mutations may arise in different genome regions. These regions may encode for polymerase, surface antigen, core/precore promoter, and comprise the X genes that significantly influence HBsAg expression and progression of HCC ( Shaha et al 2018 ; Arikan et al 2019 ). Additionally, due to the complete overlapping of pol and S genes, drug resistance and nucleos(t)ide resistance mutations occurring in the pol gene can lead to changes in its product HBsAg ( Kırdar et al 2019 ).…”