Changes of follicular helper T cells in peripheral blood of patients with newly-diagnosed type 1 diabetes mellitus

Abstract

Objective To observe the changes in follicular helper T cells (Tfh) in peripheral blood mononuclear cell (PBMC) of newly-diagnosed patients with type 1 diabetes mellitus (T1DM),to analyze its relationship with B lymphocyte and autoantibodies,and to explore the role played by Tfh cells in the pathogenesis of T1DM.Methods Eighteen patients with newly-diagnosed T1DM and 15 healthy control subjects were enrolled.The percentages of Tfh cells and B cells in PBMC with respective CD4+CXCRS+ICOS+and CD19+markers were assessed by flowcytometry.The mRNA expressions of interluekin 21 (IL-21) and Bcl-6 were detected in two groups by realtime PCR,and the association between Tfh and glutamic acid decarboxylase antibody (GADA) was analyzed.Results (1) The proportions of Tfh [(0.09 ± 0.01 vs 0.20 ± 0.01) ％,P＜0.01] and B lymphocyte [(1.68 ± 0.16 vs 3.4 ±0.25)％,P＜0.01] in PBMC from T1DM group were significantly higher than those in control group.(2) In comparison with control group,mRNA levels of Bcl-6 and IL-21 in PBMC of T1DM group were decreased by 30％ (P＜0.01) and 35％ (P＜0.05).(3) A positive correlation between the amount of Tfh cell and the titer of GADA was found (r =0.792,P ＜ 0.01).Conclusion The close relationship of Tfh cells with clinical and biochemical characteristics in newly-diagnosed patients with T1DM demonstrates an important role which may be played by Tfh cells in the pathogenesis of T1DM. Key words: Diabetes mellitus, type 1 ; Peripheral blood mononuclear cell; Follicular helper T cells