Division of Hematology/Oncology, Department of Internal Medicine, Kameda Medical Center, 929 Higashi-chou, Kamogawa-shi, Chiba, 296-8601, Japan.
Division of Nephrology, Department of Medicine, Kameda Medical Center, Kamogawa-shi, Chiba, 296-8601, Japan.
BMC Nephrol. 2021 Jan 23;22(1):40. doi: 10.1186/s12882-021-02246-9.
IgD multiple myeloma (MM) is a rare subtype of MM and light chain deposition disease (LCDD) outside the kidney is also a rare and has scarcely been reported. We report herein the details of the first reported case of LCDD involving the kidney and liver co-occurring with IgD myeloma.
A 66-year-old female with IgD MM presented with rapidly progressive acute renal failure, ascites and pleural effusion. Immunofluorescent study of revealed the characteristic linear deposition of Igκ light chain along the glomerular and tubular basement membrane in kidney. Electron microscopy showed the powdery electron-dense deposits along the tubular and glomerular basement membrane consistent with the diagnosis of LCDD. Laser microdissection followed by mass spectrometry identified only Igκ light chain with more than 95% probability confirm the diagnosis of κ-LCDD but not heavy/light chain deposition disease. Liver biopsy with immunofluorescence study revealed the linear deposition of Igκ chain along the perisinusoidal space indicating the hepatic involvement of κ-LCDD. The patient was successfully treated with combination therapy with bortezomib, cyclophosphamide, dexamethasone, and daratumumab.
This report emphasizes that prompt biopsy of affected organs and initiation of clone directed therapy led to the correct diagnosis and favorable outcome in patient with LCDD who has extrarenal involvement.
IgD 多发性骨髓瘤（MM）是 MM 的一种罕见亚型，而肾脏以外的轻链沉积病（LCDD）也很少见，几乎没有报道。我们在此报告首例肾脏和肝脏同时发生的伴有 IgD 骨髓瘤的 LCDD 的详细病例。
一名 66 岁女性患有 IgD MM，表现为进行性急性肾衰竭、腹水和胸腔积液。肾脏的免疫荧光研究显示 Igκ 轻链沿肾小球和肾小管基底膜呈特征性线性沉积。电子显微镜显示沿肾小管和肾小球基底膜的粉末状电子致密沉积物，符合 LCDD 的诊断。激光微切割后进行质谱分析仅鉴定出超过 95%概率的 Igκ 轻链，从而明确诊断为 κ-LCDD，但不是重链/轻链沉积病。肝脏活检的免疫荧光研究显示 Igκ 沿窦周间隙呈线性沉积，表明存在 κ-LCDD 的肝受累。该患者成功接受硼替佐米、环磷酰胺、地塞米松和达雷妥尤单抗联合治疗。
本报告强调，及时对受累器官进行活检，并开始针对克隆的治疗，可导致伴有肾脏外受累的 LCDD 患者得到正确诊断和良好结局。
