[Expression and Significance of PD-1 and ICOS in Patients with Primary Immune Thrombocytopenia].

To investigate the expression of programmed death receptor-1 (PD-1) and inducible costimulator (ICOS) on the surface of CD8+ T cells in peripheral blood of patients with primary immune thrombocytopenia (ITP), and explore the roles of PD-1 and ICOS in the occurrence and development of ITP.A total of 28 ITP patients treated in Tianjin Medical University General Hospital from September to December 2020 were selected, including 13 patients with newly diagnosed ITP, 15 patients with chronic ITP, and 22 healthy volunteers were recruited as control group. Flow cytometry was used to detect the expression levels of PD-1 and ICOS, and evaluate their correlation with clinical indicators.The percentage of CD8 + T cells in ITP patients of chronic group was higher than that of the newly diagnosed group and the control group (P<0.05). The expression level of PD-1 on CD8+ T cells in ITP patients of newly diagnosed group and chronic group were significantly lower than that of the control group (P<0.05), while the expression level of ICOS were significantly higher (P<0.05). In ITP patients, PD-1 was negatively correlated with platelet count (r=-0.4942, P<0.01), but positively with ICOS (r=0.4342). PD-1 and ICOS were both negatively correlated with lymphocyte count (rPD-1=-0.4374; rICOS=-0.4492).In ITP patients, the unbalanced expression of PD-1 and ICOS may interfere with the immune homeostasis of the body, which can be used as a therapeutic target for ITP patients.PD-1、ICOS在ITP患者中的表达及意义.检测原发免疫性血小板减少症（ITP）患者外周血CD8+ T细胞表面程序性死亡受体-1（PD-1）、诱导型共刺激分子（ICOS）的表达，探讨二者在ITP疾病中的意义。.选取2020年9月至12月于天津医科大学总医院血液科就诊的ITP患者28例，包括 13例新诊断患者，15例慢性患者，同时选取健康志愿者22名作为对照组。采用流式细胞术检测外周血CD8+ T细胞表面PD-1、ICOS的表达水平，并评估其与临床指标之间的相关性。.慢性组ITP患者CD8+ T细胞百分比明显高于新诊断组及对照组（P<0.05）；新诊断组及慢性组ITP患者CD8+ T细胞表面PD-1的表达水平明显低于对照组（P<0.05），而ICOS的表达水平明显高于对照组（P<0.05）；在ITP患者中，PD-1与血小板计数呈负相关（r=-0.4942，P<0.01），与ICOS呈正相关（r=0.4342）；PD-1、ICOS与淋巴细胞计数均呈负相关（rPD-1= -0.4374；rICOS=-0.4492）。.在ITP患者中，PD-1和ICOS的不平衡表达可能干扰机体的免疫稳态，可以作为ITP患者的治疗靶标。.