He Rui-juan, Xiao Hui-jie, Wang Su-xia, Guan Na, Yao Yong, Ding Jie
Department of Pediatrics, First Hospital, Peking University, Beijing 100034, China.
Zhonghua Er Ke Za Zhi. 2012 Dec;50(12):939-43.
To study the characteristics of clinicopathology and prognosis of 3 pediatric cases diagnosed as C3 glomerulopathy, and to improve the understanding of C3 glomerulopathy in children.
The medical record, plasma complement C3, Factor H (FH) and its autoantibody, and therapeutic response of the 3 cases were analyzed, and their prognosis were followed up.
Of the 3 cases, 2 were male and 1 was female, the age of onset was 9 years, 12 years, 5 years 4 months, the duration from onset to renal biopsy was 3 months, 7 months and 20 days, and the follow-up period were 2.6 years, 8 months and 1.5 years respectively.
All the 3 cases showed microscopic hematuria, with or without gross hematuria and proteinuria. Two showed persistently decreased plasma complement C3, in the other one C3 was in normal lower limit, all presented with decreased FH concertration, in 1 case anti-FH antibody was positive. Their clinical diagnosis was post-streptococcal glomerulonephritis, nephrotic syndrome (NS) nephritis type, and mesangial proliferative glomerulonephritis respectively.
All showed evident deposition of C3 on glomerular basement membrance (GBM) and mesangial region by immunofluorescence (IF) and electron dense deposit in GBM, mesangial region or para-mesangial region by Electron microscopic (EM) examination Treatment and prognosis: The case with NS showed no response to steroid, so steroid was gradually stopped after renal biopsy and replaced by angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor antagonist (ARB). The other two cases were treated with ACEI and renal protective treatment. Of the 3 cases, one gradually showed elevated serum creatinine (Scr) and decreased creatinine clearance rate (Ccr), the other two were normal, but slightly increased indications for early kidney injury.
C3 glomerulopathy is characterized by evident C3 deposition under IF. Its clinical and pathological manifestations vary a lot. The decreased plasma C3 and FH suggest that the abnormal regulation of complement system play an importment role in its pathogenesis.
研究3例诊断为C3肾小球病的儿科病例的临床病理特征及预后，以提高对儿童C3肾小球病的认识。
分析3例患者的病历、血浆补体C3、H因子（FH）及其自身抗体以及治疗反应，并对其预后进行随访。
3例中，男性2例，女性1例，发病年龄分别为9岁、12岁、5岁4个月，从发病至肾活检的时间分别为3个月、7个月和20天，随访时间分别为2.6年、8个月和1.5年。
3例均表现为镜下血尿，伴或不伴肉眼血尿及蛋白尿。2例血浆补体C3持续降低，另1例C3处于正常下限，均表现为FH浓度降低，1例抗FH抗体阳性。其临床诊断分别为链球菌感染后肾小球肾炎、肾病综合征（NS）肾炎型和系膜增生性肾小球肾炎。
免疫荧光（IF）检查均显示C3在肾小球基底膜（GBM）和系膜区有明显沉积，电镜（EM）检查显示GBM、系膜区或系膜旁区有电子致密沉积物。治疗及预后：NS患儿对激素无反应，肾活检后逐渐停用激素，换用血管紧张素转换酶抑制剂（ACEI）和血管紧张素受体拮抗剂（ARB）。另外2例采用ACEI及肾脏保护治疗。3例中，1例血清肌酐（Scr）逐渐升高，肌酐清除率（Ccr）降低，另2例正常，但早期肾损伤指标略有升高。
C3肾小球病的特征是IF下C3明显沉积。其临床和病理表现差异很大。血浆C3和FH降低提示补体系统的异常调节在其发病机制中起重要作用。
