慢性特发性血小板减少性紫癜淋巴细胞和血小板凋亡蛋白的表达

目的：从细胞凋亡的角度探讨慢性特发性血小板减少性紫癜（ITP）的发病机制。方法：用流式细胞仪检测30例ITP患者治疗前后T(CD3^ )、B（CD19^ ）淋巴细胞及血小板Fas蛋白与Fas-L蛋白的表达。结果：治疗前T淋巴细胞的Fas蛋白表达明显低于正常者，Fas-L蛋白表达明显高于正常对照者，B淋巴细胞的Fas和Fas-L蛋白表达与正常对照者相比差异无统计学意义。血小板恢复正常的患者T淋巴细胞的Fas蛋白表达上调和Fas-L蛋白表达下调，与治疗前相比差异有统计学意义，与正常对照者相比差异无统计学意义。治疗前的血小板Fas和Fas-L蛋白的表达均显著高于正常对照者。经治疗血小板恢复正常的患者血小板Fas和Fas-L蛋白表达无显著下调，与治疗前相比差异有显著性意义。结论：未治疗的ITP患者体内大量表达Fas-L蛋白的T淋巴细胞与高表达的Fas蛋白的血小板结合后，T淋巴细胞强发挥细胞毒作用，杀伤血小板；另外，血小板同时高表达Fas和Fas-L蛋白，血小板通过cis途径凋亡而减少。经肾上腺皮质激素等治疗可通过下调血小板Fas和Fas－L蛋白的表达而阻止血小板cis凋亡，下调T淋巴细胞Fas－L蛋白的表达，减少T淋巴细胞对血小板的细胞毒性作用。

The expression of Fas protein and Fas-L protein in the lymphocytes and platelets from patients with idiopathic thrombocytopenic purpura

Objective:To investigate the role of apoptosis in the pathogenesis of idiopathic thrombocytopenic purpura(ITP).Methods:Flow cytometry was used to the expression of Fas protein and Fas L protein in CD 3 + (T) and CD 19 +(B) lymphocytes and platelets of 30 ITP patients and 20 normal controls.Results:Fas protein on T lymphocytes was lowly expressed,and Fas L protein was highly expressed in untreated ITP patients,The expression of Fas and Fas L protein on B lymphocytes are normal expression. The expression of Fas was increased on T lymphocytes and that of Fal L was decreased in treated patients whose platelets were normal.The expression of Fas and Fas L protein in platelets are increased inuntreated ITP patients.The expression of Fas and Fas L protein in platelets are decreased in ITP patients whose platelets recovered to normal after therapy.Conclusion:In untreated ITP patients,T lymphocytes which overexpressed Fas L protein combined with platelets that overexpressed Fas protein may produce cytotoxicity against platelets. Furthermore,overexpressed Fas and Fas L protein simultaneously induced apoptosis of platelets.The therapy of glucocorticoid downregulated the expression of Fas and Fas L protein to inhibit Fas induced apoptosis of platelets; and downregulated the expression of Fas L protein on T lymphocytes to decrease the cytotoxicity of T lymphocytes against platelets.