激素敏感型肾病综合征患儿甲基泼尼松龙冲击前后白介素13的表达

Interleukin-13 expression before and after pulse treatment with methylprednisolone in children with steroid-responsive nephrotic syndrome

目的观察白介素13(IL-13)在小儿类固醇敏感肾病综合征(SRNS)中的变化及甲基泼尼松龙冲击治疗(MPT)对IL-13表达的影响,探讨其在SRNS发病中的作用。方法分别采用ELISA法及RT-PCR法测定20例正常儿童及28例SRNS患儿MPT前、结束后2d、5d、尿蛋白转阴后2周血清IL-13水平及外周血单个核细胞(PBMC)IL-13 mRNA水平。采用双缩脲法对SRNS患儿检测24h尿蛋白量。结果血清IL-13蛋白水平及PBMCIL-13 mRNA表达MPT前明显高于MPT结束后5d组、尿蛋白转阴后2周组及正常对照组,差异有显著性(均P<0.01);MPT结束后5d组较正常对照组高,差异有显著性(P<0.05);MPT前与结束后2d比较差异无显著性(P>0.05)。尿蛋白转阴后2周组血清IL-13蛋白水平及PBMCIL-13 mRNA表达与正常对照组比较无统计学意义。SRNS患儿血清中IL-13水平与24h尿蛋白量呈正相关。结论SRNS患儿血清IL-13及其基因表达异常,MPT对SRNS患儿IL-13在蛋白合成和基因转录两个水平上可能有抑制作用。

Objective To study serum concentration and mRNA expression of interleukin-13 （ IL-13 ） in children with steroid-responsive nephrotic syndrome （SRNS） and the effect of methylprednisolone pulse therapy （MPT） on IL-13 expression. Methods Twenty-eight children with SRNS were enrolled in this study. Serum protein level of IL-13 was measured using ELISA and IL-13 mRNA expression in peripheral blood mononuclear cells （ PBMC ） was detected with RT-PCR before MPT, 2 and 5 days after MPT, and 2 weeks after disappearance of proteinuria following MPT. Twenty-four urinary protein was measured with the biuret assay. Twenty healthy children were used as controls. Results Serum IL-13 levels （ 38.48±13.01pg/mL vs 5.18±2.71pg/mL） and PBMC IL-13 mRNA expression （1.31±0.23 vs 0.36±0.07） before MPT in SRNS patients were significantly higher than in the controls. After 5 days of MPT and 2 weeks after disappearance of proteinuria following MPT, serum IL-13 levels （15.33±7.81 and 5.35±2.12pg/mL respectively） and PBMC IL-13 mRNA expression （0.89±0.26 and 0.33±0.08 respectively） were significantly reduced （ P 〈 0.01 ）. Serum IL-13 levels and PBMC IL-13 mRNA expression in SRNS patients 2 weeks after disappearance of proteinuria following MPT were reduced to control levels, but remained at a higher level than controls 5 days after MPT. A positive correlation was found between serum levels of IL-13 and 24-hour urinary protein in SRNS patients before （ r =0.75, P 〈 0.01） and after 2 and 5 days of MPT （r=0.68, r=0.71 respectively; P 〈0.05）. Conclusions Serum IL-13 levels and PBMC IL-13 mRNA expression in children with SRNS increase. MPT can inhibit the expression of protein and mRNA of IL-13 in these patients.