重症肌无力合并抗NXP2抗体阳性皮肌炎一例报道并文献复习

Myasthenia gravis combined with anti-NXP2 antibody positive dermatomyositis:a case report and literature review

目的探讨重症肌无力(MG)合并皮肌炎(DM)的临床特征及预后,以提高临床医生对本病的认识。方法报道中南大学湘雅三医院收治的一例MG合并抗NXP2抗体阳性DM患者的临床资料,并结合文献报道的16例MG合并DM患者进行回顾性分析。结果54岁女性,主要表现为四肢近端肌无力及颈肌无力1个月、加重半个月,肌酸激酶1797 U/L,抗乙酰胆碱受体(AChR)抗体>20 nmol/L,抗NXP2抗体(+),新斯的明试验阳性,肌电图示四肢呈肌源性损害,重复神经电刺激高低频波幅递减,诊断考虑MG合并DM。17例MG合并DM患者平均年龄45岁,临床症状均有四肢肌无力及皮疹,其他症状包括吞咽困难12例(70.6%),发音或构音障碍、肌痛、呼吸困难各7例(41.2%),颈肌无力6例(35.3%),复视5例(29.4%),面肌无力、上睑下垂各4例(23.5%),肌萎缩、躯干肌无力各1例(5.9%)。经糖皮质激素治疗者15例(88.2%),联合新斯的明治疗10例,联合静脉注射免疫球蛋白7例。除合并恶性肿瘤患者死亡外(2例),其他患者经治疗后肌无力、皮疹等症状均好转。结论MG合并DM时,临床上常无眼外肌麻痹等MG常见表现,延髓肌无力突出,完善新斯的明试验、相关抗体检测、肌电图、RNS以及肌活检有助于诊断,患者经糖皮质激素治疗或联合其他治疗预后较好。

Objective To investigate the clinical features and prognosis of myasthenia gravis(MG)combined with dermatomyositis(DM)in order to improve clinicians'understanding of this disease.Methods The clinical data of a patient with MG combined with anti-NXP2 antibody positive DM admitted to the Third Xiangya Hospital of Central South University was reported,and a retrospective analysis was carried out based on 16 patients with MG combined with DM reported in the literature.Results A 54-year-old woman mainly manifested as proximal limb weakness and cervical muscle weakness for 1 month,aggravated for half a month.Blood tests showed creatine kinase 1797 U/L,anti-acetylcholine receptor(AChR)antibody>20 nmol/L,anti-NXP2 antibody positive,and neostigmine test was positive.Needle electromyography showed myogenic damage to the limbs,repeated nerve stimulation suggested decreased high and low frequency amplitude.She was diagnosed with MG combined with DM.The average age of the 17 MG patients with DM was 45 years old.The clinical symptoms included muscle weakness and rash in the limbs.Other symptoms included dysphagia in 12 patients(70.6%),dysphonia or dysarthria,myalgia,and dyspnea in 7 patients(41.2%),cervical muscle weakness in 6 patients(35.3%),diplopia in 5 patients(29.4%),facial muscle weakness and ptosis in 4 patients(23.5%),muscle atrophy and trunk muscle weakness in 1 patient(5.9%).Fifteen patients(88.2%)were treated with glucocorticoid,10 patients were treated with neostigmine,and 7 patients were treated with intravenous immunoglobulin.Two patients died of malignant tumors,and other patients'symptoms such as muscle weakness and rash improved after treatment.Conclusions Bulbar paralysis is common in patients with MG combined with DM,rather than external ophthalmoplegia.The neostigmine test,related antibody detection,electromyography,RNS and muscle biopsy are helpful for diagnosis.Glucocorticoid therapy or combined with other therapy shows a better prognosis.