Correlation of IL-15 with viral load of hepatitis B and its role in the clearance of the virus

Introduction and Aim: Hepatitis B virus (HBV) causes hepatitis B infection resulting in acute and chronic liver damage. Diagnosis of HBV involves blood tests that can distinguish acute and chronic infections. Molecular tests are also available that aid in viral detection and quantification. HBV infected individuals exhibit increasing levels of cytokines throughout the progress of infection which is thought to play an important role in the virus clearance process. Hence in this study we aim to evaluate the role of IL-15 in clearance of hepatitis B virus in acute and chronic infection. Materials and Methods: This cross-sectional hospital-based investigation conducted in Baghdad, Iraq comprised 34 patients with HBV infection and 30 apparently healthy individuals aged between 20-75 years. Blood drawn from each individual was subjected to ELISA and RT-PCR assays for detection of the virus. The serum obtained was assayed for IL-15 levels. Statistical analysis was performed on the data obtained. Results: HBsAg was detected in all acute hepatitis B patients. The study revealed that 85.29 % of acute hepatitis B patients with HBsAg by ELISA were positive by RT-PCR. The viral load was highest in patients aged 40-49 years. Patients with acute hepatitis B but detected negative by RT-PCR had the highest mean IL-15 level (22.17 pg/ml) compared to patients positive by RT-PCR and the control group (11.16 and 4.21 pg/ml, respectively). A strong negative association (R = -0.8657) existed between IL-15 level and viral load in patients with acute hepatitis B. Conclusion: High levels of IL-15 are associated with the HBV clearance in patients with acute hepatitis.