目的:报道1例以肌肉萎缩为首发症状的意义未明的单克隆丙种球蛋白病(monoclonalgammopathy of undetermined significance,MGUS )病例,并对相关文献进行复习。

方法:报道1例以肌肉萎缩为首发症状的 MGUS 病例,结合相关文献,探讨周围神经病合并单克隆丙种球蛋白病(monoclonal gammopathy,MG)的诊治要点。

结果:1 例 58 岁男性,主诉“左下肢萎缩伴上肢麻木2年余”,慢性起病且进行性加重。查体发现四肢肌肉萎缩,四肢套式感觉障碍,双侧腱反射未引出,闭目难立征阳性,串联步态不能完成。辅助检查发现周围神经损害。免疫固定电泳检测发现M蛋白阳性和 lgM-K 型条带,血清抗 GM2 抗体 lgM(+)、抗 sulfatide 抗体 lgM(+)抗 MAG 抗体 lgM(+),脑脊液抗GD1b 抗体 lgM( + )。结合病史、体征和辅助检査结果等,诊断为 lgM 型 MGUS。给予小剂量激素调节免疫治疗,血浆置换去除致病性免疫球蛋白,并辅以对症支持治疗,症状好转后出院,1年后随访,病情无进展。

结论:周围神经病患者需要常规接受血液免疫固定电泳检测筛查,并仔细与其他疾病进行鉴别。MGUS 的诊断和治疗需要神经科、影像科、血液科和病理科的多学科协作。早期发现、精准评估和长期随访有利于改善患者的预后。

Objective: To report a case of monoclonal gammopathy of undetermined significance (MGUS) with muscle atrophy as the first symptom and review the related literatures.

Methods: A case of MGUS with muscle atrophy as the first symptom was reported, and related publications were reviewedto discuss the diagnosis and treatment of MGUS with peripheral neuropathy.

Results: A 58-year-old man was admitted to the hospital with "left lower limb atrophy accompanied with upper limb numbness for more than 2 years". He had the clinical course of chronic onset and progressive aggravation. Physical examination revealed limb muscle atrophy, paresthesia, and non-elicitable bilateral tendon reflexes. Romberg sign was tested positive, and the tandem gait cannot be completed. Peripheral nerve damage was confirmed by electromyography, M protein and lgM-k type bands were found positive inimmunofixation electrophoresis analysis, In addition, anti-GM2 antibody lgM(+)anti-sulfatides antibody lgM (+)and anti-MAG antibody lgM (+) in serum as well asanti-GD1b lgM (+) in cerebrospinal fuid were found positive. The patient was diagnosedas lgM-MGUS according to medical history, physical examination and other auxiliary examinations. After maintainin glow-dose steroids application to inhibit autoimmunity,plasma exchange to remove pathogenic IgM protein, together with symptomatic support,his symptoms improved and was later discharged from hospital. The patient's condition did not develop after 1 year on follow-up visit.

Conclusion: Routine screening with blood immunofixation electrophoresis is required for patients with peripheral neuropathy, and careful differentiation from other diseases is necessary. The diagnosis and treatment of MGUS require multidisciplinary collaboration between neurology,radiology, hematology, and pathology department. Early detection accurate assessment and long-term follow-up are beneficial for improving patients'prognosis.