增生性肾小球肾炎伴晶格状结构的单克隆IgG沉积

51岁男性,病程1月,以高血压起病,肾脏损害主要表现大量蛋白尿,低白蛋白血症,伴少量镜下血尿,肾功能异常。肾外表现有轻度正细胞正色素性贫血,血清免疫固定电泳提示κ型IgG单克隆免疫球蛋白条带,骨髓活检和骨髓细胞学检查均阴性。肾活检组织学改变为肾小球系膜细胞、内皮细胞增生,毛细血管袢内较多CD68+细胞浸润,肾小球基膜内皮下大量、少量系膜区、偶见上皮侧嗜复红物沉积,沉积物免疫荧光染色仅IgG1和κ轻链阳性,电镜观察沉积物具有晶格状结构,免疫电镜证实这些晶格状的物质IgG和κ轻链阳性。该患者最终诊断为增生性肾小球肾炎伴具有晶格状结构的单克隆IgG沉积。

Proliferative glomendonephritis with monoclonal IgG deposits associated with crystal lattice features

A 51-year old man was admmited in January 2011 because of hypertension,proteinuria,hypoalbuminemia,mild microscopic hematuria and mild renal dysfunction.He had anemia and serum IgG kappa monoclonal component,while bone marrow biopsy and bone marrow cytomorphologic examinations indicated normal findings.Analysis of the kidney biopsy showed mesangial and endothelial cell proliferation with intracapillary CD68 positive cell infiltration.The massive subendothelial,mild mesangial area and rare subepithelial deposits were observed,however,they were only positive staining for IgG1 and kappa light chain.Electron microscopy showed the deposits had crystal lattice appearance.The final diagnosis was proliferative glomerulonephritis with monoclonal IgG deposit associated with crystal lattice features.