Study on correlation of the plasma IL-6 concentration with HCV RNA and liver function in HCV high-risk paid blood donors

Objective To explore the relationship of plasma interleukin 6(IL-6) concentration with HCV RNA, liver function in hepatitis C patients and investigate the role of cytokines in chronic HCV infection. Methods 138 patients with persistent HCV infection and 152 uninfected controls were selected in this study. The plasma IL-6 level and HCV viral load were detected by enzyme linked immunosorbent assay (ELISA) and fluorescence quantitative polymerase chain reaction (FQ-PCR) respectively. The spearman correlation and partial correlation analyses were used to explore their correlations with liver function indexes. Results The chronic HCV infected patients had higher plasma IL-6 level than that of healthy controls (t=-3.066, P=0.002). The IL-6 concentration had a positive correlation with alanine aminotransferase (ALT), aspartate aminotransferase (AST) (before the adjustment:r_ALT=0.186, P_ALT=0.001, r_AST=0.177. P_AST=0.003; after the adjustment:r_ALT=0.200, P_ALT=0.001, r_AST=0.127, P_AST=0.039). The HCV viral load was positively correlated with the IL-6 level in chronic hepatitis C patients (before the adjustment:r=0.199, P=0.019; after the adjustment:r=0.200, P=0.025). Conclusions The plasma IL-6 may be associated with HCV infection and chronic level. The findings provided more insights into the immune mechanism for the development of HCV infection.