Expression and significance of IL-21 in patients infected with hepatitis B virus at different stages / 实用医学杂志

ABSTRACT

Objective To determine the expression of interleukin-21 (IL-21) in patients infected with hepatitis B virus (HBV) and its association with HBV-DNA and ALT. Methods Clinical dates and blood specimen were collected from 25 unrelated healthy controls (HC) and 101 independent chronic HBV infected patients, including 25 patients in immune tolerant phase (IT), 25 in immune clearance phase (IC), 26 patients in inactive HBV carrier state (IA) and 25 patients in immune reactive phase (IR). Serum IL-21 levels were measured by Cytometric Bead Array (CBA). IL-21 mRNA and IL-21 receptor mRNA were measured by real-time PCR. Results Chronic HBV-infected patients had higher levels of serum IL-21 and IL-21 mRNA , with P <0.001 for both. In subgroup analysis, both serum IL-21 and IL-21 mRNA levels in IC, IR were higher than those in IT, IA and HC (all P < 0.001). Serum IL-21 level in IA was higher than that in HC and IT (P <0.001, P = 0.036). IL-21R mRNA levels were different between groups. Serum IL-21 level was associated with HBV-DNA (r = -0.472, P < 0.001), but not with ALT. Conclusion IL-21, up-regulated in chronic HBV infection, is associated with immune activity and may play a key role in HBV control.