PDF(Pubmed)
Abstract：
Our case report is of an elderly male with a history of IgM κ lymphoplasmacytic lymphoma (LPL) presenting with generalized neuropathy and weakness. Due to his LPL history and worsening renal function, he underwent a renal biopsy revealing the presence of μ heavy and λ light chains, revealing a diagnosis of amyloidosis with unbound heavy & light chains (AHL), a rare type of amyloidosis. His bone marrow biopsy demonstrated κ light chain restriction by flow cytometry and amyloid deposition. The patient\'s serum had elevated free κ and λ light chains with a free light chain (FLC) ratio of 3.17. Serum immunofixation was positive for IgM κ and λ light chain clones. He completed six cycles of cyclophosphamide, bortezomib, dexamethasone, and rituximab (CyBorD+R), normalizing the FLC ratio. Still, he continued to present with persistently elevated M protein, IgM κ, and λ light chains on immunofixation. Thereafter, daratumumab, a human monoclonal antibody directed against CD38 expressed on myeloma cells was initiated, which led to a negative immunofixation study after two cycles accompanied by a reduction in protein excretion in the urine. The patient achieved a complete hematological response with daratumumab. To date, our case is the only reported μ heavy and λ light chain amyloidosis patient with bi-clonal (IgM κ and λ) gammopathy to be successfully treated with daratumumab.
摘要：
我们的病例报告是一名老年男性，有IgMκ淋巴浆细胞性淋巴瘤（LPL）病史，表现为全身性神经病和虚弱。由于他的LPL病史和肾功能恶化，他接受了肾活检，发现μ重链和λ轻链的存在，揭示了未结合重链和轻链（AHL）的淀粉样变性的诊断，一种罕见的淀粉样变性.他的骨髓活检通过流式细胞术和淀粉样蛋白沉积证实了κ轻链限制。患者血清游离κ和λ轻链升高,游离轻链(FLC)比率为3.17。血清免疫固定对IgMκ和λ轻链克隆呈阳性。他完成了六个环磷酰胺周期，硼替佐米,地塞米松,利妥昔单抗（CyBorD+R），归一化FLC比率。尽管如此，他继续表现出持续升高的M蛋白，IgMκ,和免疫固定上的λ轻链。此后,daratumumab,启动了针对骨髓瘤细胞上表达的CD38的人单克隆抗体，在两个周期后，导致免疫固定研究阴性，伴随着尿液中蛋白质排泄的减少。患者使用daratumumab实现了完全的血液学反应。迄今为止,我们的病例是唯一报道的患有双克隆(IgMκ和λ)丙种球蛋白病的μ重链和λ轻链淀粉样变患者,该患者使用达雷妥单抗成功治疗.
