急性肝衰竭患者外周血调节性T细胞比率及活性变化

Changes of regulatory T cell proportion and activity in the patients with acute liver failure

目的观察调节性T（Treg）细胞在急性肝衰竭（ALF）患者外周血中的比率、活性变化及其临床意义。方法选取20名ALF患者及10名健康对照者，分离外周血单个核细胞（PBMCs）。应用流式细胞术检测各组患者PBMCs中CD4＋CD25＋CD127^low Treg细胞占CD4＋细胞的比率。通过单向混合淋巴细胞反应（MLR），观察从各组患者PBMCs中分离的CD4＋CD25＋CD127^low Treg细胞抑制淋巴细胞增殖的能力变化。同时检测外周血中超敏C反应蛋白（hsCRP）、血沉（ESR）、免疫球蛋白（Ig）等水平。结果ALF患者PBMCs中Treg细胞占CD4＋细胞的比率明显低于健康对照者[（4．20±1．34）％比（8．34±0．89）％，t=8．81，P〈0．01]。加入ALF患者分离得到的Treg细胞的MLR，Treg细胞抑制同源性PBMCs细胞增殖的能力被明显削弱，cpm=（21．48±4．14）×10^3；与健康对照者[cpm=（6．32±1．18）×10^3]比较差异有统计学意义（t=11．26，P〈0．01）。而ALF患者外周血hsCRP、ESR、Ig水平明显高于健康对照者（P〈0．05）。ALF患者外周血Treg细胞下降与hsCRP和IgG升高呈负相关（r=-0．634，P〈0．01；r=-0．596，P〈0．01）。结论ALF患者存在Treg细胞数量及活性的下降，Treg细胞等免疫调节因素可能在ALF的发病机制中发挥作用。

Objective To explore the changes of regulatory T （Treg） cell proportion and activity in peripheral blood of patients with acute liver failure （ALF）. Methods Twenty patients with ALF and 10 healthy controls were selected in this study. Peripheral blood mononuclear cells （PBMCs） were obtained by using density gradient centrifugation. The proportion of CD4 ＋ CD25 ＋CD127^low Treg cells in the CD4 ＋ cells was detected by using flow cytometry in PBMCs of enrolled cases. The immune activity of Treg ceils isola- ted from PBMCs was observed by using a suppression assay of allogeneic mixed lymphocyte response （MLR）. In addition, the levels of high sensitivity C reactive protein （hsCRP）, erythrocyte sedimentation rate （ESR） and immunoglobalin in peripheral blood were also detected. Results The patients with ALF had a significantly lower percentage of Treg ceils in CD4 ＋T cells in PBMCs than healthy controls [ （4. 20 ± 1.34） % vs. （ 8.34 ± 0. 89 ） %, t = 8.81, P 〈 0.01 ]. The suppressing homologous PBMCs proliferation ability of Treg cells isolated from the patients with ALF was significantly weakened in MLR [ cpm = （21.48 ±4. 14） × 10^3], which had a statistically significant difference compared with healthy controls [cpm = （6. 32 ±1.18） × 10^3 ,t = 11.26,P 〈0. 01 ]. The levels of hsCRP, ESR and immunoglobulin in peripheral blood in the patients with ALF were significantly higher than in healthy controls （ P 〈 0. 05 ）. The percentage of Treg cells were negatively correlated with hsCRP and IgG （ r = - 0. 634, P 〈 0. 01 ; r = - 0. 596, P 〈 0. 01 ）. Conclusion There is a decrease in both quantity and activity of Treg cells in the patients with ALF. Treg cells and other immuno-regulation factors may play an important role in the pathogenesis of ALF.