High level of IL-27 positively correlated with Th17 cells may indicate liver injury in patients infected with HBV

Abstract

Background: Interleukin-6/IL-12 family cytokines play a key role in inflammatory diseases via their effects on the differentiation or regulation of T helper cells.

Aims: The aim of this study was to determine the role of interleukin-27 (IL-27) and its association with helper T cells in hepatitis B virus (HBV)-infected patients.

Methods: Samples were assessed from 51 HBV-infected patients [28 chronic hepatitis B (CHB) subjects and 23 acute-on-chronic liver failure (ACLF) subjects] and 18 normal controls (NC). Serum IL-27 levels were examined by enzyme-linked immunosorbent assay. Circulating helper T cells were determined using flow cytometry and associations between IL-27 expression and helper T cells were analysed.

Results: Serum IL-27 levels rose in HBV-infected patients (502.88 ± 23.35 pg/ml) compared to (NC, 277.14 ± 23.96 pg/ml, P < 0.0001). Furthermore, it significantly increased in patients with ACLF (587.90 ± 33.08 pg/ml) when compared with CHB (433.04 ± 26.57 pg/ml, P = 0.001). However, no statistically significant differences were observed between IL-27 and the presence of HBeAg. High levels of IL-27 then positively correlated with Tbil levels (r = 0.401, P = 0.004), but negatively associated with prothrombin time activity levels (r = -0.496, P < 0.001), and a slightly negative correlation trend with HBV-DNA loads (r = -0.228, P = 0.107) existed in these HBV-infected subjects. Additionally, frequency of circulating interleukin-17-producing CD4(+) T cells (Th17 cells) increased in HBV-infected patients (ACLF, mean, 5.39%; CHB, median, 3.12%) as compared to NC subjects (median, 2.22%, P < 0.0001). Moreover, correlation analysis showed that serum IL-27 level was positively associated with circulating Th17 cells (r = 0.342, P = 0.036).

Conclusion: These results provided evidence that IL-27 was positively correlated with Th17 cells commitment, and may exerted a proinflammatory effect in the development of liver injury in HBV-infected patients.

Keywords: IL-27; Th17 cells; hepatitis B virus; immunopathogenesis.