Noto Rio, Kamiura Nozomu, Ono Yuichiro, Tabata Sumie, Hara Shigeo, Yokoi Hideki, Yoshimoto Akihiro, Yanagita Motoko
Department of Clinical Nephrology, Kobe City Medical Center General Hospital, 2-1-1, Minatojimaminamimachi, Chuo-ku, Kobe-city, Hyogo, 650-0047, Japan.
Department of Clinical Hematology, Kobe City Medical Center General Hospital, Hyogo, Japan.
BMC Nephrol. 2017 Apr 6;18(1):127. doi: 10.1186/s12882-017-0524-7.
Proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID) is a form of renal involvement by monoclonal IgG deposits that was found in mesangial, subendothelial or subepithelial regions. The distribution of glomerular deposits was completely different from that in monoclonal immunoglobulin deposition disease. PGNMID is reported to be rarely associated with a hematological malignancy. Previously, only five cases of PGNMID with multiple myeloma have been reported. However, the pathogenic relationship between PGNMID and multiple myeloma was unclear because a detailed description was not provided. We report that a patient with PGNMID associated with multiple myeloma was treated with bortezomib and dexamethasone and underwent the second renal biopsy after treatment, showing that chemotherapy was effective for PGNMID clinically and pathologically.
A 75-year-old man presented with progressive leg edema, had nephrotic range proteinuria, hypoalbuminemia, moderate renal failure, and occult blood in his urine. Electrophoresis results showed serum and urinary monoclonal spikes of IgGκ type immunoglobulin. A renal biopsy specimen showed lobular mesangial proliferation with mesangiolysis, glomerular micro-aneurysm, and endocapillary hypercellularity. Immunofluorescence results revealed strong granular capillary and mesangial staining for IgG1, C3 and κ light chain in glomeruli without tubular deposits of any immunoglobulin. Electron microscopy also showed dense granular deposits in subendothelial and mesangial areas. PGNMID associated with multiple myeloma (IgGκ type) was diagnosed on the basis of a subsequent bone marrow examination. Bortezomib and dexamethasone therapy significantly reduced proteinuria and elevated serum albumin level. Eight months later, the second renal biopsy showed no active lesions and that the IgG1 and κ light chain deposits had drastically disappeared.
This is the first case of PGNMID with multiple myeloma successfully treated with bortezomib and dexamethasone in which comparative renal biopsies were performed before and after treatment. Our findings suggest the pathogenesis of PGNMID and therapeutic options for PGNMID.
单克隆IgG沉积性增殖性肾小球肾炎（PGNMID）是一种由单克隆IgG沉积引起的肾脏受累形式，其沉积于系膜、内皮下或上皮下区域。肾小球沉积物的分布与单克隆免疫球蛋白沉积病完全不同。据报道，PGNMID很少与血液系统恶性肿瘤相关。此前，仅报道过5例PGNMID合并多发性骨髓瘤的病例。然而，由于未提供详细描述，PGNMID与多发性骨髓瘤之间的致病关系尚不清楚。我们报告了1例PGNMID合并多发性骨髓瘤的患者，接受硼替佐米和地塞米松治疗，并在治疗后进行了第二次肾活检，结果显示化疗在临床和病理上对PGNMID有效。
一名75岁男性出现进行性腿部水肿，伴有肾病范围蛋白尿、低白蛋白血症、中度肾衰竭及尿潜血。电泳结果显示血清和尿液中有IgGκ型免疫球蛋白的单克隆峰。肾活检标本显示小叶系膜增生伴系膜溶解、肾小球微动脉瘤和毛细血管内细胞增多。免疫荧光结果显示肾小球中IgG1、C3和κ轻链呈强颗粒状毛细血管和系膜染色，肾小管无任何免疫球蛋白沉积。电子显微镜检查也显示内皮下和系膜区域有致密颗粒状沉积物。根据随后的骨髓检查，诊断为PGNMID合并多发性骨髓瘤（IgGκ型）。硼替佐米和地塞米松治疗显著降低了蛋白尿水平，提高了血清白蛋白水平。8个月后，第二次肾活检显示无活动性病变，IgG1和κ轻链沉积物大幅消失。
这是首例采用硼替佐米和地塞米松成功治疗的PGNMID合并多发性骨髓瘤病例，并在治疗前后进行了对比肾活检。我们的研究结果提示了PGNMID的发病机制及PGNMID的治疗选择。
