Associations of apoptosis with B cell and expression of interleukin-17 in patients with rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the relation between the apotosis of B cells in the peripheral blood (PB) and the expression of interleukin (IL)-17 in patients with rheumatoid arthritis (RA).Methods The proportions of apoptosis of B cells in the PB of 80 patients with RA and 80 healthy controls were measured by flow cytometry.B cells in the PB of 20 RA and 20 healthy individuals were isolated by MACS and Western blotting was used to detect the Bcl-2 and Caspase-3 protein levels.IL-17 levels were detected by enzyme-linked immunosorbent assay (ELISA).T-test and linear regression were used to analyze the data.Results The proportions of apoptosis of B cells in the PB of patients with RA and healthy controls were (14±6)％ and (24±9)％ respectively.The rate of apoptosis of B cells in patients with RA was significantly less than healthy controls (t=2.737,P=0.021).The Bcl-2 protein level of B cells in the PB of patients with RA group was significantly higher than that of control group (26±10,12±6,P＜0.01).Conversely,the Caspase-3 protein level of B cells in the PB of patients with RA group was significantly lower than that of the control group (16±7,31±12,P＜0.01).ELISA detected elevated level of serum IL-17 in the patients with RA as compared with controls [(69±19),(27±10) pg/ml,t=4.631,P=0.014].There was a negative correlation between the level of IL-17 and apoptosis of B cells in patients with RA (r=0.36,P＜0.01).Conclusion The elevated bcl-2 and reduced caspase-3 of B cells in patients with RA further proves there is abnormal apoptosis of B cells in RA patients.There is negative correlation between the expression of IL-17 and apoptosis of B cells in patients with RA and IL-17 can inhibit B cell apoptosis.