Roles of circulating soluble interleukin (IL)-6 receptor and IL-6 receptor expression on CD4+ T cells in patients with chronic hepatitis B

Objectives: The objective of this study was to investigate the potential clinical roles of circulating soluble interleukin (IL)-6 receptor (sIL-6R) and IL-6R expression on CD4+ T cells (CD4+ IL-6R+ T cells) in chronic hepatitis B (CHB) patients. Methods: One hundred and thirty-three subjects, including 72 CHB patients, 27 asymptomatic carriers, eight acute hepatitis B (AHB) patients, and 26 healthy donors were included in this study. Plasma IL-6 and sIL-6R levels were measured by enzyme-linked immunosorbent assay (ELISA); the frequency of CD4+ IL-6R+ T cells was detected by flow cytometry analysis. Results: Our data showed a significant increase in plasma sIL-6R levels and the frequency of CD4+ IL-6R+ T cells in peripheral blood in CHB patients compared to asymptomatic carriers and healthy controls (both p < 0.05). The elevated prevalence of CD4+ IL-6R+ T cells was positively associated with increased serum alanine aminotransferase levels in CHB patients (r = 0.316, p = 0.007), but was not correlated with serum hepatitis B virus (HBV) DNA load. Moreover, CHB patients with an HBV DNA load >1.0 x 10(6) copies/ml had a lower level of plasma sIL-6R than those with an HBV DNA load <1.0 x 10(6) copies/ml. Conclusions: Circulating sIL-6R and CD4+ IL-6R+ T cells were increased in CHB patients. Elevated plasma sIL-6R is probably associated with HBV elimination, and CD4+ IL-6R+ T cells in peripheral blood might contribute to the pathogenesis of liver injury in CHB patients. (C) 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.