成人肾病综合征患者肾小管megalin表达变化及其可能机制探讨

Expression of megalin on renal tubule in adult patients with nephrotic syndrome

目的检测成人不同病理类型肾病综合征患者肾小管Megalin表达的差异,进一步探讨肾病综合征患者蛋白尿形成和肾小管损伤的发生机制。方法选取我院确诊为原发性肾病综合征患者62例,按照肾脏病理分为微小病变组(MCD)、膜性肾病组(MN)、局灶节段硬化组(FSGS)。收集各病例组临床资料以及血清、尿液等临床指标,包括患者病程、起效时间、ALB、BUN、Scr、CH、TG、HB、24小时尿蛋白定量等;应用免疫组织化学方法检测各病例组肾小管megalm的表达;各病例组行肾脏病理常规染色,并根据肾小管损伤标准进行肾小管-间质损伤程度评分。分析肾小管megalin表达量与临床和病理指标的相关关系。结果 MCD组肾小管megalin表达量与对照组比较无统计学差异,而MN组、FSGS组肾小管megalin表达均显著低于MCD组和对照组,以FSGS组降低最为显著。各病理类型亚组肾小管megalin的表达水平与临床指标无显著相关关系。全组肾病综合征、MCD亚组、MN亚组megalin的表达水平均与肾小管损伤评分存在负相关关系。结论某些病理类型肾病综合征患者肾小管megalin表达降低可能与蛋白尿毒性有关,megalin表达的下降反过来可能参与这些患者的尿蛋白形成。

Objective Expression of megalin on renal tubule in different pathological types of nephrotic syndrome patients were detected,to explore the possible mechanisms of proteinuria and renal tubule injury.Methods 62 primary nephrotic syndrome patients were selected and divided into minimal change disease,membranous nephropathy group and focal segmental sclerosis.Clinical indicators were collected,including duration of patients,onset time,serum albumin, blood urea nitrogen,serum creatinine,cholesterol,triglycerides,hemoglobin,and 24-hour urinary protein.Immunohisto-chemistry was used to detect the megalin expression on renal tubule of each group.Renal pathology was stained by HE, PASM,and Masson staining,then the renal tubule injury scores were tested according to the the tubular injury stand-ards.Results The results of semi-quantitative analysis showed that the expression of megalin on proximal tubule be-tween the MCD group and control group has no significant difference,the expression of megalin in the MN group and FSGS group was significantly lower than in the MCD group,the expression of megalin in the FSGS group was signifi-cantly lower than in the MN group.There were no correlation between megalin expression in proximal tubule and clini-cal indicators in various pathological subgroups.Negative correlations between megalin expressions and renal tubule in-jury scores in the whole group,MCD group,MN group were found.Conclusion The decreasing expressions of megalin on proximal tubule in patients with heavier pathological types of nephrotic syndrome were in relation with the toxicity of urine protein,and this decreasing of megalin expression then contribute to formation of proteinuria.