The levels and clinical significance of myeloid-derived suppressor cell in peripheral blood from juvenile idiopathic arthritis / 中华风湿病学杂志

ABSTRACT

Objective Myeloid-derived suppressor cell (MDSC) have the potential to suppress autoimmune T cell response, while the levels and function of it had not been studied in juvenile idiopathic arthritis (JIA). Therefore, we used flow cytometry to detect MDSC in peripheral blood of JIA and analyzed its correlation with cytokines, providing clinical basis for the generation and function of MDSCs in JIA. Methods A total of 34 patients with JIA were included. The disease activity was evaluated by calculating the 28-joint Disease Activity Score (DAS28)based on clinical information. JIA patients were divided into the active disease group and inactive disease group according to the DAS28 score. Twenty healthy controls were recruited from the Health Care Section of our hospital.The frequency of MDSC in peripheral blood from JIA patients and healthy controls were determinedby flow cytometry; enzyme-linked immunosorbent assay (ELISA) was used to detect plasma Interleukin (IL)-1β, IL-6, IL-10 and IL-17A of JIA patients and healthy controls; RT-quantitative polymerase chain reaction (qPCR) was performed to detect the expression levels of signal transducer and activator of transcription 3 (STAT3),IL-17A gene in patients with JIA and control subjects,and Spearman correlation was used to investigate the association between MDSC and DAS28 score, cytokines;non-parametric test and Spearman test were used for two group comparisons and correlation analysis, respectively.Results The frequency of MDSC [(6.2±4.2)% vs (1.2±1.6)%, Z=-5.258, P<0.01], and the levels of plasma cytokines IL-1β [(175±306) pg/ml vs (66±29) pg/ml, Z=-2.246, P=0.034], IL-6 [(86.6±257.2) pg/ml vs (14.0± 2.6)pg/ml,Z=-3.123,P=0.002),IL-10[(44±36)pg/ml vs(24±6)pg/ml,Z=-2.166,P=0.03],IL-17A[(9.1±17.6) pg/ml vs (2.7±0.4) pg/ml, Z=-3.965, P<0.01] incre-ased significantly in JIA patients compared with healthy control group, while STAT3 had no differences (P>0.05). The frequency of MDSC correlated positively with DAS28 and erythrocyte sedimentation rate(ESR) disease activity (r=0.447, P=0.037; r=0.456, P=0.033), IL-1β (r=0.496, P=0.044), IL-10 (r=0.498, P=0.035); negatively cor-related with the STAT3 mRNA (r=-0.522, P=0.041); but not correlated with the IL-6, IL-17A by Spearman's test. Conclusion We have found that the frequency of MDSC in JIA increases and is associated disease activity, closely associated with inflammatory cytokines. The frequency of MDSC can be used as a clinical indicator to reflect inflammatory activity in JIA, However,the current knowledge of MDSC is incomplete and further experiment is required.