Department of Neurosciences, University of Padova, Padova, Italy.
Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Padova, Italy.
J Peripher Nerv Syst. 2023 Jun;28(2):262-265. doi: 10.1111/jns.12540. Epub 2023 Mar 10.
Neuropathy is a frequent complication of Waldenström's macroglobulinemia (WM), the most common being a demyelinating polyneuropathy with anti-myelin associated glycoprotein (MAG) antibodies, but also cryoglobulins, vasculitis, neurolymphomatosis, and amyloidosis. We describe a patient with IgM/kappa WM who presented with a severe, not length-dependent, peripheral neuropathy as clinical onset of IgM/kappa-related amyloidosis.
A 69-year-old woman came to our attention for weight loss, gait imbalance and sensory loss at upper limbs. In her medical history, she was in hematological follow-up for WM, and had undergone left carpal tunnel release. At neurological evaluation she had weakness and loss of sensation at upper limbs up to the elbows, more at the left side, gait was unsteady with right foot drop. Hypotrophy and areflexia were present at four limbs. Sensory loss and vibration sense were dramatically reduced. She underwent extensive diagnostic workup.
Laboratory workup revealed an IgM/kappa monoclonal paraprotein of 16 g/L and increased NT-proBNP; anti-MAG antibodies were absent. Bone marrow biopsy demonstrated a population of neoplastic B-lymphocytes. Total-body CT scan and echocardiogram were negative. Neurophysiology revealed a symmetric, no length dependent sensory-motor polyneuropathy Periumbilical fat biopsy was positive for amyloid. Sural nerve biopsy detected amyloid in the wall of an epineurial vein.
This case report describes a rare and unusual manifestation of IgM-related AL amyloidosis in WM. The patient presented with a subacute clinically asymmetric neuropathy with no pain or dysautonomic features as clinical onset of IgM/kappa-related amyloidosis. Sural nerve biopsy was crucial for the diagnosis.
神经病是瓦尔登斯特伦巨球蛋白血症（WM）的常见并发症，最常见的是脱髓鞘多发性神经病伴抗髓鞘相关糖蛋白（MAG）抗体，但也有冷球蛋白血症、血管炎、神经淋巴瘤病和淀粉样变性。我们描述了一例 IgM/κ WM 患者，其首发表现为严重的、非长度依赖性周围神经病，为 IgM/κ 相关淀粉样变性的临床发病。
一名 69 岁女性因体重减轻、步态不稳和上肢感觉丧失来就诊。在她的病史中，她因 WM 正在接受血液学随访，并已接受左侧腕管松解术。在神经学评估时，她上肢无力和感觉丧失到肘部，左侧更明显，步态不稳定，右脚下垂。四肢有萎缩和反射消失。她接受了广泛的诊断检查。
实验室检查显示 IgM/κ 单克隆丙种球蛋白为 16g/L，NT-proBNP 升高；抗 MAG 抗体阴性。骨髓活检显示有一群肿瘤性 B 淋巴细胞。全身 CT 扫描和超声心动图均为阴性。神经生理学显示对称性、无长度依赖性感觉运动多发性神经病。脐周脂肪活检阳性，存在淀粉样物质。腓肠神经活检显示外膜静脉壁有淀粉样物质。
本病例报告描述了 WM 中 IgM 相关 AL 淀粉样变性的一种罕见且不常见的表现。患者表现为亚急性、不对称性、无疼痛或自主神经功能障碍的神经病，为 IgM/κ 相关淀粉样变性的临床发病。腓肠神经活检对诊断至关重要。
