The proportion of Th17 cells and IL-17 expression levels in peripheral blood of patients with chronic hepatitis B and their clinical significance

Objective To analyze T helper 17( Th17) cell proportion and interleukin 17( IL-17) levels in peripheral blood of patients with chronic hepatitis B( CHB) and healthy controls,and to evaluate their correlations with disease severity,serum hepatitis B virus( HBV) DNA load and liver injury markers,in order to investigate Th17 cells' role in the pathogenesis of CHB. Methods The Th17 cell proportion and IL-17 levels in peripheral blood of 93 CHB patients( the mild,moderate and severe CHB patients had 21,37 and 35 cases,respectively) and 28 healthy controls were determined by flow cytometry and enzyme-linked immunosorbent assay( ELISA). The mRNA expression levels of IL-17 and RAR-related orphan nuclear receptor C( RORC) of purified CD4+T cells after stimulating with anti-CD3 and anti-CD28 antibodies were analyzed by real-time fluorescence polymerase chain reaction( PCR). The IL-17 levels in the supernatant of purified CD4+T cells after stimulating with anti-CD3 and anti-CD28 antibodies were evaluated by ELISA. The data were analyzed statistically,and their relations with serum HBV DNA load,liver injury markers,and so on were analyzed. Results Compared with those of healthy control group,the proportion of Th17 cells in peripheral blood of CHB group was significantly higher,and increased with disease severity. The Th17 cell proportion,IL-17 levels and RORC mRNA levels in severe CHB group were significantly higher than those in moderate and mild CHB groups and healthy control group( P 0. 05). There was no statistical significance in serum IL-17 levels among the groups( P 0. 05). The IL-17 levels in the supernatant of purified CD4+T cells after stimulating with anti-CD3 and anti-CD28 antibodies from CHB group were significantly higher than those from healthy control group( P 0. 05),and the IL-17 levels in the supernatant from severe CHB group were higher than those from moderate and mild groups( P 0. 05). The Th17 cell proportion in peripheral blood of CHB group showed a positive correlation with serum alanine aminotransferase( ALT) level( P 0. 01),and showed no correlation with serum HBV DNA load. Conclusions The increased Th17 cell proportion in CHB patients may be the one of the factors for liver inflammatory response and liver injury and cause the progression of CHB.