肾小球系膜区IgM沉积在儿童原发性肾小球疾病中的意义

目的：探讨肾小球系膜区IgM沉积在儿童原发性肾小球疾病中的意义。方法：选取2005年6月至2011年6月于北京大学第一医院儿科住院并行肾穿刺活检的原发性肾小球疾病患儿作为研究对象。根据免疫荧光下肾小球系膜区有无IgM沉积进行分组，将肾小球系膜区IgM沉积≥+且IgM免疫荧光强度≥其他免疫球蛋白荧光强度的患儿作为IgM沉积组，其余患儿为对照组。回顾性分析两组的临床、病理特点和随访等情况。结果：125例原发性肾小球疾病患儿进入分析，其中IgM沉积组76例，对照组49例。①两组在发病年龄、血总蛋白、血白蛋白、血总胆固醇、肌酐清除率、肾早期损伤指标、高血压和肾功能不全发生率等方面差异无统计学意义。IgM沉积组24 h尿蛋白定量及血IgM水平显著高于对照组（P分别为0.025和0.038）。②IgM沉积组肾小球硬化及小动脉病变发生率显著高于对照组(P分别为0.002和0.039)，基底膜增厚发生率显著低于对照组（P=0.000）。③对激素治疗反应两组差异无统计学意义（P=0.364）。④随访2~78个月，两组肾功能不全及ESRD发生率差异无统计学意义。⑤IgM沉积组3/76例男性患儿行重复肾活检。除1例首次肾活检已诊断为局灶节段性肾小球硬化外，余2例在第2次肾活检时均由系膜增生性肾小球肾炎转化为局灶节段性肾小球硬化。结论：伴系膜区IgM沉积的原发性肾小球疾病患儿蛋白尿程度更重，肾脏病理改变亦更突出。对于伴系膜区IgM沉积的原发性肾小球疾病患儿应格外关注并密切随访，警惕其进展为局灶节段性肾小球硬化的可能。

The significance of mesangial IgM deposition in childhood primary glomerulopathy

Objectives：To explore the significance of mesangial IgM deposition in childhood primary glomerulopathy. Methods：Clinical and renal pathological data were collected from patients with childhood primary glomerular diseases who had undergone renal biopsies at Peking University First Hospital from June 2005 to June 2011. Patients were divided into two groups: IgM deposit group comprised patients with mesangial IgM deposits and control group comprised patients without mesangial IgM deposits. A retrospective analysis was carried out on all children who met the criteria. Results：Of the 618 children with renal biopsy speciments, 125 children met both clinical and pathologic diagnosis. IgM deposit group included 76 cases, while control group contained 49 cases. There was no difference between the two groups in disease onset age, incidence of hypertension, renal insufficiency, serum total protein, serum albumin, serum cholesterol, CCr or kidney early injury parameters. Serum IgM was significantly higher in IgM deposition group than that in control group (P=0.038). Proteinuria in IgM deposit group was significantly more severe than that in control group (P=0.025). IgM deposit group had a significantly higher incidence of glomerular sclerosis and arteriole injury than control group (P=0.002, 0.039). Whereas the occurrence of glomerulopathy basement membrane thickness in IgM deposit group was significantly lower than that in control group（P=0.000）. There was no significant difference between the two groups when comparing the response to steroid treatment. During the follow-up period, there was no significant difference in the incidence of renal insufficiency between the two groups. Conclusions：The childhood primary glomerulopathy with mesangial IgM deposits has more severe proteinuria and pathological changes than that without mesangial IgM deposits. More attention should be paid on patients with mesangial IgM deposits and the possible histological transition to focal segmental glomerulosclerosis.