低CD40L表达在儿童单纯性肾病综合征低IgG血症发生中的作用

The Lowering CD40L Expression of Peripheral T Lymphocytes and Hypo IgG in Children with Idiopathic Nephrotic Syndrome

为研究单纯性肾病综合征低IgG血症的发生机制。采用逆转录多聚酶链反应 (RT PCR ) ,流式细胞术 (FCM )等方法检测患儿外周血T淋巴细胞表面CD40配体 (CD40L )表达。结果在发作期CD40LmRNA及蛋白质表达降低 ,恢复期其表达可接近正常水平 ,且CD40L表达量与血清IgG水平呈显著正相关。体外实验中加入CD40单克隆抗体 (CD40mAb )可使患儿PBMC产生IgG及其亚类水平增高 ,但仍未达正常水平。单纯性肾病综合征低IgG血症的发生是综合因素作用的结果 ,CD40L信号减弱导致免疫球蛋白 (Ig )同种型转换障碍是因素之一。

To investigate the mechanism involved in the hypoimmunoglobulin G (hypo IgG) in children with idiopathic nephrotic syndrome (INS),the CD40 ligand (CD40L) expression on the peripheral blood T lymphocytes was tested by reverse transcription polymerase chain reaction (RT PCR) and flow cytometry (FCM) The CD40L mRNA and protein expression in acute INS children were less than those of the normal control and increased in remission stage with a good correlation to the serum IgG level In vitro,the production of IgG and IgG subclasses by patient's peripheral blood mononuclear cell (PBMC) was increased but still less than the control stimulated with anti CD40mAb It concludes that hypo IgG in INS patients may be involved by comprehensive factors in which the lowering CD40L expression,partially arresting signal transduction in Ig isotype switching,is an important one