Xu Junhui, Yu Xiaojuan, Wang Suxia, Yan Miao, Wang Mangju, Ou Jinping, Wang Lihong, Liu Huihui, Cen Xinan
Department of Hematology, Peking University First Hospital, No.8 Xi Shi Ku Street, Xi ChengDistrict, Beijing, 100034, China.
Department of Nephrology, Peking University First Hospital, Beijing, China.
World J Surg Oncol. 2021 Jan 22;19(1):24. doi: 10.1186/s12957-021-02135-3.
Multiple myeloma causes different types of renal injury. C3 glomerulonephritis (C3GN) is characterised by an abnormal deposition of complement C3 in the glomeruli due to abnormal activation of the alternative pathway of the complement system. While the association between C3GN and multiple myeloma has been well established, mild renal injury by C3GN in multiple myeloma patients with high levels of light chain has not been reported.
A 55-year-old Chinese man presented with proteinuria. Combined with immunofixation electrophoresis, bone marrow biopsy, and renal biopsy, he was diagnosed with IgA-type multiple myeloma accompanied by C3GN and light chain proximal tubulopathy without crystal deposits. Although he had a higher level of lambda serum-free light chain, the renal injury in this patient was mild. After treatment with four courses of BD, one course of PAD, and autologous stem cell transplantation, he achieved a very good partial hematologic response with stable renal function.
In multiple myeloma, the light chain reaches a certain level and persists, resulting in C3GN renal impairment. Early diagnosis and early intensive treatment are critical for the prognosis of such patients.
多发性骨髓瘤可导致不同类型的肾损伤。C3肾小球肾炎（C3GN）的特征是由于补体系统替代途径的异常激活，补体C3在肾小球中异常沉积。虽然C3GN与多发性骨髓瘤之间的关联已得到充分证实，但在轻链水平较高的多发性骨髓瘤患者中，C3GN所致的轻度肾损伤尚未见报道。
一名55岁的中国男性因蛋白尿就诊。结合免疫固定电泳、骨髓活检和肾活检，他被诊断为IgA型多发性骨髓瘤，伴有C3GN和无晶体沉积的轻链近端肾小管病。尽管他的λ型血清游离轻链水平较高，但该患者的肾损伤较轻。经过四个疗程的BD、一个疗程的PAD治疗及自体干细胞移植后，他获得了非常好的部分血液学缓解，肾功能稳定。
在多发性骨髓瘤中，轻链达到一定水平并持续存在，导致C3GN肾损害。早期诊断和早期强化治疗对此类患者的预后至关重要。
