Darouich Sihem, Goucha Rym, Jaafoura Mohamed Habib, Zekri Semy, Kheder Adel, Ben Maiz Hédi
Electron Microscopy Laboratory, Faculty of Medicine of Tunis, Tunis, Tunisia.
Ultrastruct Pathol. 2011 Feb;35(1):42-6. doi: 10.3109/01913123.2010.532902.
Membranoproliferative glomerulonephritis with isolated C3 deposits (MPGNC3) is an uncommon condition characterized by overt glomerular C3 deposits in the absence of immunoglobulins and intramembranous dense deposits. Here the authors describe the clinical and morphological features of primary MPGNC3 in a 13-year-old boy and critically review the previously published cases. The patient presented with nephrotic syndrome and microscopic hematuria. Blood tests revealed very low circulating C3 levels. The renal biopsy exhibited subendothelial, subepithelial, and mesangial deposits, with C3 but not immunoglobulins seen on immunofluorescence. This case and the review of the literature indicate that the serum complement profile with decreased levels of C3 and normal levels of classical pathway components together with glomerular deposits containing exclusively complement C3 is highly suggestive of alternative pathway activation. The diagnosis of acquired and/or genetic complement abnormalities in some cases supports that complement dysregulation is implicated in the pathogenesis of MPGNC3. Such data show great promise to provide new therapy strategies based on modulation of the complement system activity.
孤立性C3沉积的膜增生性肾小球肾炎（MPGNC3）是一种罕见疾病，其特征是在无免疫球蛋白和膜内致密沉积物的情况下出现明显的肾小球C3沉积。本文作者描述了一名13岁男孩原发性MPGNC3的临床和形态学特征，并对先前发表的病例进行了批判性回顾。该患者表现为肾病综合征和镜下血尿。血液检查显示循环C3水平极低。肾活检显示内皮下、上皮下和系膜沉积物，免疫荧光检查可见C3但未见免疫球蛋白。该病例及文献回顾表明，血清补体谱显示C3水平降低而经典途径成分水平正常，同时肾小球沉积物仅含补体C3，这强烈提示替代途径激活。某些病例中获得性和/或遗传性补体异常的诊断支持补体调节异常与MPGNC3的发病机制有关。这些数据为基于调节补体系统活性提供新的治疗策略显示出巨大前景。
