BACKGROUND: Chronic hepatitis C virus (HCV) infection leads to life-threatening complications worldwide. Immunomodulation signals the response to virus clearance. The immune-suppressive molecule human leukocyte antigen-G (HLA-G) has been shown to function in inhibiting both innate and adaptive immune responses. The objective of this study was to investigate the expression of HLA-G and IL-37 in sustained virological response (SVR) and non-SVR HCV-positive patients before and after complete treatment with a combination of pegylated interferon (IFN) and ribavirin (RBV).

MATERIAL AND METHODS: Our study included 132 chronic hepatitis C patents who received combined therapy with IFN-a and RBV. Both SVR and non-SVR patients were included. The end-of-treatment response was defined as undetectable HCV RNA at week 48. Patients with end-of-treatment response were detected by HCV RNA at 24 weeks after therapy. The expression levels of HLA-G and IL-37 at the end and 24 weeks after treatment were detected by ELISA.

RESULTS: Plasma HLA-G and IL-37 were significantly increased in HCV-infected patients compared with healthy individuals before treatment. Furthermore, HLA-G in SVR patients was noticeably decreased after treatment, while HLA-G in non-SVR patients had no changes after treatment. Additionally, both in SVR and non-SVR patients, the expression of IL-37 was remarkably reduced compared with baseline after treatment.

CONCLUSIONS: These findings suggest that elevation of HLA-G and IL-37 in HCV may play an important role in response to combined therapy with IFN-a and RBV. Monitoring the expression of HLA-G during therapy could contribute to adjusting the treatment program of HCV-infected patients.

Keywords: Case-Control Studies, Drug Therapy, Combination, Enzyme-Linked Immunosorbent Assay, HLA-G Antigens - blood, Hepatitis C, Chronic - drug therapy, Interferon-alpha - therapeutic use, Interleukin-1 - blood, Ribavirin - therapeutic use, Solubility