再生障碍性贫血患者共刺激信号系统的变化及意义

Changes of costimulatory signals in aplastic anemia patients

目的:探讨共刺激信号系统在再生障碍性贫血(AA)发病机制中的作用。方法:应用流式细胞术检测22例重型再障(SAA)患者和12轻型再障(CAA)患者外周血T细胞共刺激信号分子CD28和B细胞CD28配体CD80和CD86的表达。同时体外培养SAA单个核细胞12h,检测培养前后T细胞表面CD28表达的变化。结果:SAA患者外周血CD4+/CD28+、CD8+/CD28-T细胞与正常对照比较明显升高。免疫抑制剂治疗有效者,CD8+/CD28-T细胞表达降低;CAA患者外周血CD4+/CD28-、CD8+/CD28-T细胞较正常对照升高;CAA较SAA患者CD8+/CD28-细胞明显升高。AA患者外周血B细胞共刺激信号配体CD80、CD86无明显变化。体外培养12h后CD8+/CD28-T细胞较培养前明显升高。结论:T细胞共刺激信号分子CD28的变化,导致某些T细胞亚群表达增加,与AA发病有关。

Objective: To explore the role of costimulating system in the pathogenesis of aplastic anemia(AA). Methods: The expression of costimulatory molecule CD28 in T cells and the expressions of the CD28 ligands of CD80 and CD86 in B lymphocytes in AA patients were determined by flow cytometry. Meanwhile, the mononuclear cells of severe aplastic anemia(SAA) patients were cultured in vitro for 12 hours to investigate the changes of CD28 in T cells before and after culture. Results: In SAA patients,the proportions of CD4+/CD28+ T lymphocytes and CD8+/CD28- T lymphocytes were higher than that in normal. After immunsuppression therapy, the proportion of CD8+/CD28- was decreased. In chronic aplastic anemia(CAA) patients,the proportion of CD4+/CD28- T cells was higher than that in the control. The expression rate of CD8+/CD28- was higher than those in the control and SAA patients. After culture in vitro, the proportion of CD8+/CD28- T cells was significantly decreased. Conclusion: The changes of costimulatory molecular CD28 in T cells result in high expressions of some subtypes of T cells, which have a relationship with the pathogenesis of AA.