Molecular and immunological investigation of Hepatitis B virus in Al-Muthanna province, Iraq

Hepatitis B virus (HBV) infection is an important public health problem in Iraq. Chronic HBV infection is a risk factor for liver cirrhosis (LC) and hepatocellular carcinoma (HCC), but little is known about the mechanisms involved in the progression of HBV￾related diseases. It is known that the host immune response is associated with the clinical outcomes of patients with HBV infection. Immunomodulatory factors such as cytokines play a role in the progression and treatment of HBV-related diseases. Interleukin-35 (IL￾35) is a newly identified inhibitory cytokine. It is emphasized that IL-35 can control inflammation and thus limit HBV liver damage. Therefore, it raises the possibility of IL￾35 to be a target for new treatments for hepatitis B disease. 120 patients with HBV infection (84 chronic hepatitis and 36 acute hepatitis) and 30 healthy control groups in Al-Muthanna State were included in the study. Serum levels of IL-35 were measured in these groups and viral DNA amplification was performed. According to the findings, IL￾35 levels were found to be significantly lower in HBV patients compared to healthy controls. 10 viral DNAs were extracted from serum samples of patients with HBV infection. A PCR protocol has been designed for amplification of the polymerase gene from the HBV genome and Sanger sequencing of the gene. Sequences were aligned with HBV reference sequences for phylogenetic analysis and characterization of genetic diversity. Populations show heterogeneity in HBV genotype frequency distributions. Six HBV genotypes have been identified (A, B, C, D, E, and H). The most common genotype was D (47%), while the frequency rate of C genotype was the least observed genotype (4%). In addition, the majority of patients showed mixed HBV genotypes (two, three, four or five) with different genotypic combinations. As a result, HBV genotype D was found to be the most common genotype among Iraqi HBV patients from Al-Muthanna Province. In conclusion, this study includes the impact of HBV infection on public health and the main findings of a study to understand the mechanisms of this infection.