T helper 17 cell in patients with rheumatoid arthritis mediated by interleukin-38 / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effect of interleukin (IL)-38 on T helper 17 (Th17) cells in patients with rheumatoid arthritis (RA).Methods Total RNA were extracted and reverse transcribed into complementary DNA.Real-time polymerase chain reaction (PCR) technique was used to determine the gene expression of IL-38 at transcription level.Enzyme linked immune sorbent assay (ELISA) was used to detect the levels of IL-38 and IL-17 in peripheral blood.The percentage of peripheral blood Th17 cells was determined by Flow cytometry.Statistical analysis was conducted with t-test and Mann-Whitney U rank test.Results ① IL-38 mRNA expression from RA patients (2.9±4.0) was significantly reduced as compared with normal controls (5.8±3.6),(Z=-1.28,P＜0.05).IL-38 protein expression from RA patients (0.44±0.03) was lower than healthy controls (0.72±0.58),(Z=-1.59,P＜0.05).② The number of Th17 cells from RA patients (11.7±3.2) increased compared with healthy controls (7.9±2.3),(Z=-1.98,P＜0.05).The counts of Th17 cells from RA patients was negatively correlated with IL-38 (r=-0.38,P＜0.05).③ The level of peripheral blood IL-17 in RA (64±52) was significantly higher than normal controls (35±8),(Z=-2.17,P＜0.05).The level of IL-17 in RA was negatively correlated with IL-38 (r=-0.31,P＜0.05).④ IL-38 caused a significant decrease in the number of Th17 cells from RA patients (5.7±1.2) compared with untreated cells (7.9±2.3),(Z=-1.57,P＜0.05).Conclusion The decrease of IL-38 level in RA patients has resulted in the excessive activation of Th17 cells,which triggers the occurrence of RA.