Profiles of serum soluble programmed death-1 and programmed death-ligand 1 levels in chronic hepatitis B virus-infected patients with different disease phases and after anti-viral treatment

Background Soluble programmed death-1 (sPD-1) and soluble programmed death-ligand 1 (sPD-L1) play a role in immune regulation of chronic hepatitis B virus (HBV) infection. Aim To investigate the profiles of serum sPD-1 and sPD-L1 in chronic HBV-infected patients with different disease phases and after anti-viral treatment. Methods A total of 99 chronic HBV-infected patients were enrolled and divided into HBeAg-positive chronic HBV infection (EPI) group, HBeAg-positive chronic hepatitis B (EPH) group, HBeAg-negative chronic hepatitis B (ENH) group and HBeAg-negative chronic HBV infection (ENI) group. Eleven healthy subjects were included as healthy controls (HCs). Thirty-two EPH patients received anti-viral treatment with nucleos(t)ide analogues and were followed up to 5 years. Serum sPD-1 and sPD-L1 levels were detected by Multiplex Immunoassays. Results Serum sPD-1 and sPD-L1 levels of chronic HBV infected patients were significantly higher than that of HCs (P < 0.01). Patients in EPH, ENH and EPI groups had higher serum sPD-1 and sPD-L1 levels than that in HCs (P < 0.01). After anti-viral treatment, serum sPD-1 and sPD-L1 levels declined rapidly. EPH patients with HBeAg clearance after 2 years of anti-viral treatment showed lower baseline HBeAg and sPD-1 levels compared to those without HBeAg clearance. Conclusions Serum sPD-1 and sPD-L1 levels varied among chronic HBV infected patients with different disease phases. Lower baseline sPD-1 levels were associated with HBeAg clearance after 2 years of anti-viral treatment in EPH patients.