儿童C3肾小球病的临床与病理特征

Clinical and pathological characteristics of children with Ca glomerulopathy

目的探讨儿童C3肾小球病（C3G）的临床、病理特征及治疗方案。方法对7例临床、肾脏病理确诊为C3G患儿的临床、病理资料进行回顾性分析，并对其预后转归进行随访。结果7例患儿中女4例，男3例；起病年龄1.5～10.4岁[（7.7±3.1）岁]；发病至肾活检时间1～6个月[（3.4±2.4）个月]，其中例5发病4.2年重复肾活检；确诊年龄1.8～13.3岁[（8.4±3.6）岁]。临床特征：7例患儿中6例有血尿，其中1例肉眼血尿，5例镜下血尿；6例低补体C3血症；5例有大量蛋白尿、低蛋白血症；2例伴贫血。5例行H因子、H因子抗体检测，其中1例H因子降低，H因子抗体均阴性。4例行基因检测，1例C3基因有5个单核苷酸多态性（SNP）（R304R、T612T、V807V、A915A、P1632P）、CFH基因有2个SNP（p.H402Y、p.E936D），余患儿未检测出异常。诊断为肾炎型肾病综合征4例，肾炎综合征2例，单纯型肾病综合征1例。病理特征：免疫荧光显示均有C3沉积，其中6例伴其他免疫蛋白成分沉积。光镜表现为膜增生性肾小球肾炎3例，毛细血管内增生性肾小球肾炎2例，系膜增生性肾小球肾炎1例，毛细血管内增生性IgA肾病1例。电镜诊断致密物沉积病3例，余4例均符合光镜诊断，结合临床诊断为C3肾小球肾炎。治疗及随访：给予甲泼尼龙冲击后足量激素联合免疫抑制剂治疗，随访1.1～5.6年[（2.6±1.8）年]，尿检完全正常4例，尿微量蛋白轻度增高伴少量镜下血尿2例，尿蛋白±～＋＋伴镜下血尿1例。结论C3G临床、病理表现多样，诊断需要病理结合临床、血清学、基因学检测；早期诊断、激素联合免疫抑制剂治疗可改善预后。

Objective To.investigate the clinicopathological features and treatment of children with C3 glomerulopathy （ C3 G）. Methods Seven children diagnosed as C3 G by clinical and pathological characteristics were enrolled in this study. The clinicopathological data and the prognosis were analyzed. Results Of the 7 cases, 4 cases were female and 3 cases were male,with the mean age of （7.7 ± 3.1 ） years old （1.5 -10.4 years old） at onset,the duration from onset to renal biopsy was （3.4 ± 2.4） months（ 1 -6 months） and 1 of them had a second renal biopsy 4.2 years later, and mean age was （ 8.4 ± 3.6 ） years old （ 1. 8 - 13.3 years old） on diagnosis. Clinical features ： among the 7 patients,6 cases had hematuria, among them 1 case had gross hematuria and 5 cases had microscopic hematuria;6 cases had low level of serum complement C3,5 cases had heavy proteinuria and low serum albumin, and anemia was observed in 2 cases respectively. Five cases had complement factor H and H factor antibody by examination, and 1 of them had low serum factor H, but none of them had serum antibody to factor H. Four cases had genetic evaluation, and only 1 case revealed risk variants in the C3 gene（R304R,T612T,V807V,A915A,P1632P）and CFH gene（p. H402Y, p. E936D）. Clinically,4 cases were diagnosed as nephrotic syndrome of nephritis type,2 cases were diagnosed as nephritic syndrome, and 1 case was diagnosed as nephrotic syndrome of simple type. Immunofluorescence study showed that all the cases had intense deposition of C3 , and 6 cases were accompanied by the deposition of immunoglobulin. Under light microscopy,3 cases showed the feature of membrane proliferative glomemlonephritis,2 cases with endocapillary prolifera-tive glomerulonephritis, 1 case with mesangial proliferative glomerulonephritis, and 1 case with endocapillary proliferative IgA nephropathy. Under electron microscopy ,3 cases who had typical ribbon - like dense deposits in glomerular basement membrane were of dense deposit disease, and the rest were C3 glomerulonephritis. All patients had steroid and immune inhibitor treatment,and during the follow - up stage of （2.6 ± 1.8） years（ 1.1 -5.6 years） ,4 ca- ses showed normal urinalysis ,2 cases had microproteinurine and microscopic hematuria ,and 1 case had urinary protein ± to ＋＋ and microscopic hematuria. Conclusions C3 G has variety of pathological - clinical manifestation. Interpretation of individual cases depends on integration of information from the biopsy together with clinical, serological, and genetic features. Patients with steroid and immune inhibitor treatment had some clinical improvement of their urinalysis.