小儿类固醇敏感肾病综合征甲泼尼龙冲击治疗对白介素18表达的影响

Interleukin-18 expression before and after methylprednisolone pulse treatment in children with steroid-sensitive nephrotic syndrome

目的:观察白介素18(IL-18)在小儿类固醇敏感肾病综合征(SSNS)中的变化及甲泼尼龙冲击治疗(MPT)对IL-18表达的影响,探讨其在SSNS发病中的作用。方法:采用ELISA法及RT-PCR法测定20例正常儿童及27例SSNS患儿MPT前、结束后2 d、5 d、尿蛋白转阴后2周血清IL-18蛋白水平及外周血单个核细胞(PBMC)IL-18mRNA水平。采用双缩脲法检测SSNS患儿24 h尿蛋白量。结果:IL-18蛋白水平及IL-18 mRNA表达MPT前明显高于MPT结束后5 d、尿蛋白转阴后2周及正常对照组,差异十分显著(P均<0.01);MPT结束后5 d较正常对照组高,差异显著(P<0.05);MPT前与结束后2 d比较,尿蛋白转阴后2周与正常对照组比较差异不显著。SSNS患儿血清中IL-18蛋白水平与24 h尿蛋白量呈正相关。结论:SSNS患儿血清IL-18及其基因表达异常。MPT对SSNS患儿IL-18在蛋白合成和基因转录两个水平上有抑制作用,测定血清中IL-18水平可作为观察病情活动状态的一个免疫学指标。

Objective： To investigate the serum level and mRNA expression of interleukin-18 （IL-18） before and after the methylprednisolone pulse therapy （MPT） in children with steroid-sensitive nephrotie syndrome （SSNS）. Methods： The serum level and mRNA expression of IL-18 were determined in 27 SSNS children and 20 healthy children by enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction, respectively. Results： The serum level and mRNA expression of IL-18 in SSNS children before MPT were significantly higher than those in SSNS children 5 days after MPT and 2 weeks after proteinuria disappeared and healthy children （,all P〈0.01 ）, No difference in the serum level and mRNA expression of IL-18 was found between SSNS children 2 weeks after proteinuria disappeared and healthy children （P 〉 0,05）. The serum IL-18 level positively correlated with 24-hour urine protein in SSNS children. Conclusion： The serum level and mRNA expression of IL-18 is abnormal in SSNS children. MPT has the inhibitory effect on the protein synthesis and gene transcription in SSNS children, and the serum IL-18 level can indicate the state of illness.