Peripheral regulatory T cells in systemic lupus erythematosus patients: the relationship with organ damage and the influence of treatment regimens / 中华风湿病学杂志

ABSTRACT

Objective To explore the distribution characteristics and function of peripheral regulatory T cells (CD4+CD25+Foxp3+T cells) in patients with systemic lupus erythematosus (SLE).In addition,we analyzed the relationship between peripheral regulatory T cells and organ damage and the influence of different treatment regimens on them.Methods Two hundred and six SLE patients and 38 healthy volunteers were enrolled,which included 12 patients with untreated new-onset lupus,11 patients with drug withdrawal more than six months and 183 patients with treatments.Phenotypic and functional analysis of peripheral blood CD4+CD25+Foxp3+T cells were performed by flow cytometry.The correlations of CD4+CD25+Foxp3+ T cells with disease activity,organ involvement were analyzed.Thealtered frequency of CD4+CD25 +Foxp3+T cells under different treatment regimens was compared.Statistical Package form Soci-science (SPSS) 21.0 software was used for data analysis,Student's t test,one-way ANOVA,Mann-Whitney T test,Kruskal-Wallis test,Chi-square test,Simple linear correlation analysis was used.Results CD4 +CD25 +Foxp3 + T cells were significantly increased inactive SLE patients [1 1.9％ (9.3％,16.0％),mean difference =104.71,P＜0.01] and inactive SLE patients [11.0％(7.7％,14.7％),mean difference=86.10,P＜0.01] compared with healthy controls [6.1％(5.3％,7.4％)].CD4+CD25+Foxp3+T cellsshowed sign-ificantly positive correlations with SLEDAI-2K (r=0.191,P＜0.05),dsDNA (r=0.262,P＜0.05),ESR (r=0.208,P＜0.05) and lgG (r=0.163,P＜0.05),and significantly negatively correlated with complementC3 (r=-0.201,P＜0.05) and C4 (r=-0.227,P＜0.05).Compared with patients without organ damage (Occult lupus),the CD4+CD25+Foxp3+T cells were increased in SLE patients with organ damage,especially those with skin involvement [10.9％(7.8％,13.1％),mean difference=56.93,P＜0.05] and renal involvement [12.1％(9.1％,16.0％),mean difference=77.26,P＜0.05].The proportion of CD4+CD25+Foxp3+T cells had no significant difference between SLE patients with treatments and patients with untreated new-onset lupus.The expressions of CTLA-4 [(53±15)％,t=7.04,P＜0.01],GITR [(42±19)％,t=2.64,P＜0.01] and ICOS [(28±9)％,t=4.27,P＜0.01] on CD4+CD25+Foxp3+T cells were significantly lower in SLE patients than in healthy controls [CTLA-4 (71±4)％,GITR (53±10)％ and ICOS (41±6)％].IL-17 synthesized by CD4+CD25+Foxp3+T cells in SLE patients [3.0％(1.8％,3.9％)] was significantly higher than that in healthy controls [1.0％(0.7％,1.2％),Z=-4.40,P＜0.01].Conclusion The peripheral regulatory T cells are significantly increased in SLE patients and correlate with disease activity and organ damage.However,their inhibitory function is defective and they have more pro-inflammatory character-istics.