共刺激分子CD40L在RA患者T细胞亚群中的异常表达

目的　探讨共刺激分子CD4 0L在类风湿关节炎 (RA)患者的T细胞亚群上的表达异常与免疫功能紊乱的关系。方法　用流式细胞仪采用直接免疫荧光法测定 4 6例RA患者和 2 0例健康对照人外周血T细胞表面标志CD3、CD4、CD8的表达情况及CD4 0L在CD4 + T和CD8+ T细胞上的表达。用IMMAGE免疫分析仪 ,速率散射比浊法测定血清中免疫球蛋白的水平。结果　RA患者CD3+ CD4 + 细胞较正常对照组显著增高 (P <0 .0 5 ) ,CD3+ CD8+ 细胞较正常对照组显著降低 (P <0 .0 5 ) ,CD4 + T细胞和CD8+ T细胞上的CD4 0L的表达都较对照组显著增高 (P <0 .0 5 ) ;血清中 3种免疫球蛋白IgG、IgA、IgM的水平均较对照组显著增高 (P <0 .0 5 )。结论　RA患者以CD4 + T细胞活化为主 ,CD4 + T细胞和CD8+ T细胞上高表达的CD4 0L为T细胞活化提供第二信号 ,促使RA患者的细胞免疫功能亢进 ,同时诱导B细胞增生 ,产生大量免疫球蛋白。CD4 0 CD4 0L途径在RA免疫功能紊乱中起了重要作用

Expression of costimulatory molecule CD40L in T cell subpopulation in RA patients

Objective To investigate the relationship between abnormal expression of costimulatory molecule CD40L in T cell subpopulation and the immune disfunction in patients with rheumatoid arthritis (RA). Methods In 46 RA patients and 20 healthy controls, CD3, CD4, CD8, and CD40L on the surface of T cells were labeled and determined by immunofluorescence and flow cytometry, respectively; IgG, IgA, and IgM in serum were determined by rate nephelometry. Results As compared with controls, the CD3 + CD4 + T cells in RA patients were significantly increased (P < 0.05) but the CD3 + CD8 + T cells were significantly decreased (P < 0.05). The CD40L expression level in CD4 +T cells and CD8 +T cells in RA patients were both significant higher that in healthy controls (P < 0.05) while the levels of IgG, IgA, and IgM in serum of RA patients were significant higher than those in healthy controls (P < 0.05). Conclusion As a second signal, increased CD40L expression in T cells interacts with CD40 in B cells, activates the T and B cells, promotes the hyperfunction of cellular immunity, and induces the cellular proliferation of B cells in RA patients. As a result, a lot of immunoglobulin are produced. CD40-CD40L pathway plays an important role in immune disfunction of RA patients.