Methylation Pattern of Hepatitis B Virus X Gene in Infected Patients

Objective: A recent field of research in epigenetics is DNA methylation which involves the CpG island in the genome that subsequently controls transcription and translation of targeted genes. In the hepatitis B virus (HBV) genome, there are three CpG islands which tend to be methylated. The aim of the current study is to determine the methylation pattern of the HBV X gene in chronically infected HBV patients.
Methods: Study participants comprised 45 chronically infected HBV patients. According to the presence of the HBeAg, patients were divided into two groups, HBeAg positive (n=24) and HBeAg negative (n=21). Initially, viral DNA was treated with natrium bisulfate. Then, analysis was performed with two sets of methylated and non-methylated primers by the MSP method.
Results: The overall methylation rate in serum samples of hepatitis B infected patients was 35.5%; the rate in the HBeAg positive patients was 20.8%, whereas it was 52.3% in HBeAg negative patients. There was a significantly higher rate of methylation in serum samples of HBeAg negative patients compared to HBeAg positive patients (student's t-test; P=0.02).
Conclusion: Methylation of HBV can be used as a new mechanism to control the progression of viral infection. This methodology can be useful for determining the characteristics of clinical stages of this infection.