狼疮性肾炎患者CD4^+淋巴细胞减少机制的初步探讨

MECHANISM OF REDUCTION OF CD4^+ CELL IN PATIENTS WITH LUPUS NEPHRITIS

目的 :探讨CD95表达在狼疮性肾炎 (LN)患者CD4 +淋巴细胞减少中所起的作用。 方法 :采用CD4 +CD95和CD8+CD95双荧光标记及CD4 +细胞的原位杂交DNA链断端标记 ,结合流式细胞术和DNA琼脂糖电泳对LN患者外周血单个核细胞的免疫分型及凋亡特征进行分析。 结果 :①LN患者较正常人CD4 +细胞比例明显减少 (P <0 0 1) ,CD8+细胞比例明显升高 (P <0 0 1)。②LN患者的CD4 +细胞有 5 2 1%表达CD95 ,较正常人 ( 2 4 8± 7 6% )表达明显升高 (P <0 0 1) ;而LN患者CD8+细胞表达CD95的比例 ( 2 6 1± 5 5 % )较正常人( 2 1 5± 5 9% )略有升高 (P >0 0 5 )。③DNA琼脂糖电泳显示 ,5 0 μg/L的抗 CD95IgM可以引起LN患者CD4 +细胞的凋亡 ,而在正常人DNA电泳带上无DNA“Ladder”出现。采用dUTP FITC标记显示 ,经 5 0 μg/L抗 CD95IgM作用后 ,正常人CD4 +细胞的标记率为 5 1± 1 4 % ,而LN患者则为 3 2 0± 5 0 % ;浓度增加到 10 0 μg/L时 ,分别增加到 17 8± 5 8%和 5 9 1± 3 4 %。 结论 :Fas受体在LN患者CD4 +细胞上的表达比例增加 ,表达Fas受体的CD4 +细胞对其受体的敏感性增加 ,这可能在LN患者CD4

OBJECTIVE To investigate the effect of Fas receptor(CD95) expression on reduction of CD4 + cells in patients with lupus nephritis. METHODOLOGY The immunophenotypes of peripheral blood lymphocytes were analyzed by employing CD3/CD4,CD3/CD8,CD3/CD16+CD56,CD4/CD95,CD8/CD95 double labeling assay.Apoptosis of CD4 + cells in patiens with LN was examined by using DNA gel electrophoresis and in situ end labeling of fragmented DNA. RESULTS The proportion of CD4 + cells in LN patients was lower than that in normal volunteers. The proportion of CD8 + cells in LN patients was higher than that of normal volunteers. The proportion of CD4 + CD95 + cells was higher than that in normal volunteers, whereas the proportion of CD8 + CD95 + cell was a little bit higher than that of normal volunteers. Agarose gel electrophoresis of genomic DNA from CD4 + cells showed that a typical DNA Ladder pattern was found on CD4 + cells in patients induced by both 50ng/ml or 100ng/ml anti CD95 IgM mAb, DNA ladder pattern was found on CD4 + cells of normal volunteers induced by 50ng/ml but 100ng/ml anti CD95 IgM mAb.In situ labeling of fragmented DNA showed that 32 0±5 0% CD4 + cells were labeled by dUTP FITC whereas 5 1±1 4% CD4 + cells in normal volunteer were labeled after treatment with anti CD95 IgM mAb at 50ng/ml.With the increment of anti CD95 IgM concentration to 100ng/ml,17 8±5 8% of CD4 + cells in normal volunteer and 59 1±3 4% of CD4 + cells in LN patients were labeled by dUTP FITC. CONCLUSION Increased proportions of CD4 + cells and CD4 + CD95 + cells in LN patients may be implicated in the pathologenesis LN.