Rope Robert, Kambham Neeraja, Arora Neiha
Division of Nephrology.
Department of Pathology, Stanford University School of Medicine, Stanford, and.
Clin Nephrol Case Stud. 2017 Aug 17;5:48-53. doi: 10.5414/CNCS109160. eCollection 2017.
Renal disease associated with paraproteinemias is classically predicated upon pathologic paraprotein deposition in the kidney. However, growing evidence suggests that paraproteins may be able to systemically activate complement or neutrophils to drive renal damage. This may provide an alternative pathologic mechanism for renal injury in rare cases.
We report a case of a patient with crescentic pauci-immune glomerulonephritis presenting with rapidly progressive renal failure, polyarthropathy, and a purpuric rash in association with a monoclonal immunoglobulin G κ-light-chain producing multiple myeloma. Serum anti-neutrophil cytoplasmic antibodies were not detected. Kidney biopsy, including with Pronase digestion, did not reveal pathologic paraprotein deposition. Two previously published similar case reports are also discussed.
We propose a novel pathologic mechanism involving monoclonal proteins as a trigger for pauci-immune glomerulonephritis, potentially via complement dysregulation and/or neutrophil activation. This requires further epidemiologic and mechanistic study.
与副蛋白血症相关的肾脏疾病传统上基于副蛋白在肾脏中的病理性沉积。然而，越来越多的证据表明，副蛋白可能能够系统性地激活补体或中性粒细胞，从而导致肾脏损伤。在罕见情况下，这可能为肾损伤提供另一种病理机制。
我们报告了一例新月体性寡免疫性肾小球肾炎患者，该患者表现为快速进展性肾衰竭、多关节病和紫癜性皮疹，同时伴有产生单克隆免疫球蛋白G κ轻链的多发性骨髓瘤。未检测到血清抗中性粒细胞胞浆抗体。肾脏活检，包括用链霉蛋白酶消化，未发现病理性副蛋白沉积。还讨论了两篇先前发表的类似病例报告。
我们提出了一种新的病理机制，即单克隆蛋白可能通过补体失调和/或中性粒细胞激活引发寡免疫性肾小球肾炎。这需要进一步的流行病学和机制研究。
