The Absolute Number Of Th17 And Regulatory T Cells In Peripheral Blood Of Patients With Rheumatoid Arthritis And The Effect Of Low Dose Of IL-2 Treatment On The Number Of Th17 And Treg

Objective:To compare the lymphocyte subtypes of healthy control and patients with rheumatoid arthritis;to explore the difference of Th17 and Treg cells between the RA patients and healthy control,and compare the absolute number of Th17 and Treg cells between different disease activity group and health control;to explore the correlation between the absolute number of these two kinds of cell and the index of disease activity such as DAS28,ESR,SJC and TJC;to explore the effect of DMARDS and low dose of IL-2 on the absolute number of these two kinds of cell and the ratio of them.Methods:Patients with RA(n = 342)and healthy controls(n = 93)were included in our study.Peripheral blood samples of them were quantified by FCM.Clinical data was collected to investigate the relationship,including age,sex,tender joint count(TJC),Swollen joint count(SJC),erythrocyte sedimentation rate(ESR),C-reactive protein(CRP)and Disease activity(DAS28).The absolute number of T cells,B cells,Th cells,CD3+CD8+T cells and NK cell in initial treat patients were compared to them in healthy individuals.Both absolute numbers and proportions of Treg and Th17 cells in peripheral blood,defined as the CD4+CD25+FOXp3+T or CD4+IL-17+T cell population,were examined by flow cytometry in 342 patients with RA with different 28-joint Disease Activities(DAS28),including 75 who had never received disease-modifying antirheumatic drugs(DMARD)and 151 who were receiving or had received DMARD.Among these patients,112 consented at enrollment to receive rhIL-2 treatment.Before and after treatment,the Th17 and Treg cells in peripheral blood were analyzed by flow cytometry.Results:Compared to healthy individuals,the absolute number of NK cells in initial treat patients was significantly low.The absolute count of Treg cells in patients with RA was significantly low compared with that of healthy controls(P<0.05),but the absolute count of Th17 cell was no different between RA and healthy controls.There is no significant difference between the long-term DMARDS treatment patients and initial RA.After the course of rhIL-2 treatment,there was a significant increase in the absolute count of Th17 and Treg cells in the CD4+T cell population(P < 0.01),but Th17/Treg was significantly low after the treatment.Conclusion:Compared to the healthy individuals,RA patients are more often infected.The data suggest that the decrease of Treg cell number,defined as the CD4+CD25+FOXp3+population,may contribute to the pathogenesis of RA.Over the treatment of rhIL-2,there was a more significant increase in the absolute count of Treg cells than that of Th17,and consequently restore the balance of Th17/Treg.