Abstract:

To investigate the clinical and pathological features of idiopathic membranous nephropathy （IMN） in children. Methods　The clinicopathological features of children with renal-biopsy-diagnosed IMN between July 1999 and July 2009 in our hospital were retrospectively analyzed in our study. Results　Thirteen pediatric patients diagnosed with IMN were included. The median age was 11.4（3.0～14.5）years with 11 males and 2 females. The median interval time between renal biopsy and the onset of IMN was 3.7（1.4～65.3）months. Due to IMN，8 children presented with nephritis-type nephrotic syndrome（NS），1 with simplex-type NS，3 with proteinuria and hematuria and 1 with recurrent macroscopic hematuria at the initial visit. One case had hypertension. Renal insufficiency was not noted in any patient. The Results of renal histopathology suggested that： （1）Four cases were in stage Ⅰand 9 in stage Ⅱ. Four cases showed glomerulus sclerosis （the percentages of glomerulus sclerosis were 11.8%，2.9%，7.5%，4.5%，respectively） and 1 case showed segmental sclerosis（the percentage of segmental sclerosis was 4.5%）. Three cases were associated with tubular atrophy. Formation of crescent fiber cells occurred in 1 case（3.8%）. （2）The predominant immunoglobulins in the subepithelial deposits were IgG and C3（12 and 10 in 12 cases，respectively）. Among them，a few cases were combined with IgM，Fg，C1q and IgA deposition，but the depositional strength was significantly weaker than IgG and C3. （3）Under electron microscope，13 cases showed different degrees of membrane thickening. Intracapillary microthromb were observed in two cases. According to different clinicopathology features，the patients were treated with prednisone and/or immuno-suppressive drugs therapy，combined or separately used with angiotensin converting enzyme inhibitor/angiotension receptor blocker（ACEI/ARB）. In 9 cases with NS due to IMN，5 patients achieved complete remission（CR），1 achieved partial remission（PR） and 3 failed to the previous therapy. The 3 unresponsive patients all achieved CR after the combined treatment with mycophenolate mofetil（2 cases） or high-dose IVIG（1 case）. Among the 3 proteinuria-hematuria patients，1 case had negative proteinuria but persistent microscope hematuria after therapy，and the rest 2 cases were both lost to follow-up. Macroscopic hematuria successfully disappeared but microscope hematuria was persistentin the recurrent macroscopic hematuria patient. Conclusions　IMN is much more common in school-age boy and it mainly presents with nephritis-type NS. Most patients are in stageⅠorⅡ.Immunofluorescence reveals that the predominant immunoglobulins in the subepithelial deposits are IgG and C3. All the cases show different degrees of membrane thickening under electron microscope. Nowadays，there are no unified and effective treatments for pediatric IMN. It is necessary to establish a normalized management，treatment and follow-up system for childhood IMN in China.

Key words: idiopathic membranous nephropathy, child, clinical pathology

摘要：

探讨儿童特发性膜性肾病（IMN）的临床和病理特征。方法　1999年7月至2009年7月在中山大学附属第一医院确诊的IMN患儿13例，回顾性分析其临床病理特征、治疗及转归情况。结果　13例IMN患儿中男11例，女2例；就诊时中位年龄为11.4（3.0～14.5）岁；肾穿时中位病程为3.7（1.4～65.3）个月。确诊时临床表现为肾病综合征（NS）9例（单纯型1例，肾炎型8例），血尿蛋白尿3例，复发性肉眼血尿1例，伴高血压1例（7.7%）。所有患儿的肾功能均正常。肾脏病理结果：（1）光镜病理分期：Ⅰ期4例，Ⅱ期9例。4例伴肾小球球性硬化（球性硬化肾小球百分比分别为11.8%、2.9%、7.5%、4.5%），1例伴节段性硬化（节段硬化肾小球百分比为4.5%），3例伴肾小管萎缩，1例伴细胞纤维性新月体形成（3.8%）。（2）免疫荧光：以IgG、C3在肾小球基底膜（GBM）上皮下沉积为主（前者12/12例、后者10/12例），少数伴IgM、Fg、C1q和IgA沉积，但沉积强度较IgG、C3弱。（3）电镜：13例患儿GBM均有不同程度增厚，2例毛细血管腔内出现微血栓。根据患儿临床表现及病理分期予激素和（或）免疫抑制剂治疗，联用或单用血管紧张素转化酶抑制剂/血管紧张素Ⅱ受体拮抗剂。9例NS患儿中，完全缓解（CR）5例，部分缓解（PR）1例，无效3例（其中2例患儿改用霉酚酸酯治疗获CR，1例加用大剂量丙种球蛋白冲击治疗后获CR）；3例血尿蛋白尿患儿中，1例尿蛋白转阴，但仍有持续性镜下血尿，2例失访；1例复发性肉眼血尿患儿治疗后肉眼血尿消失，但仍有镜下血尿。结论　儿童IMN多发于学龄期男性，临床表现以肾炎型NS为主。病理分期以Ⅰ、Ⅱ期多见，免疫荧光以IgG、C3在GBM上皮下沉积为主，电镜示所有患儿GBM均有不同程度增厚。目前国内儿童IMN尚无统一治疗方案，亟需在临床实践中加强随访及注重个体化治疗，以提高疗效，改善预后。

关键词: 特发性膜性肾病, 儿童, 临床病理特征