Myasthenia gravis is an autoimmune neuromuscular junction disorder primarily mediated by autoantibodies against the acetylcholine receptor (AChR). It is now widely recognized that the total titer of anti-AChR antibodies does not correlate directly with clinical severity and shows significant interindividual variability. This review focuses on the structure of the AChR, the three major pathogenic mechanisms mediated by anti-AChR antibodies, the pathogenic differences associated with distinct antigenic epitopes, the characteristics of various immunoglobulin subclasses, and the limitations of current antibody detection methods. It further explores future directions in antibody profiling and functional assessment. By systematically analyzing the complexity and heterogeneity of anti-AChR antibodies, this article underscores the critical role of precision medicine in the management of myasthenia gravis.
ObjectiveTo explore the clinical features of myasthenia gravis (MG) harboring both acetylcholine receptor antibody (AChRAb) and muscle-specific tyrosine kinase antibody (MuSKAb) positivity.MethodsWe searched PubMed, Web of Science, Embase and China National Knowledge Infrastructure databases (from inception to November 2016), to collect the case reports of MG with both AChRAb and MuSKAb positivity. Along with one case discovered in Department of Neurology, West China Hospital, the clinical data of the cases were retrospectively analyzed.ResultsA total of 13 double-seropositive MG patients were enrolled in this study, demonstrating a marked female predominance (including 1 male and 12 females) and a younger age at onset [(31.07±24.77) years]. During the disease course, 10 of the included patients presented severe bulbar involvement, dyspnea and neck weakness, with myasthenic crisis in 6 individuals. Among the 11 patients with detailed records, abnormal thymus glands comprised 4 thymus hyperplasia and one thymoma. While the response to oral pyridostigmine was unsatisfactory in 11 double-seropositive MG patients, ranging from mild benefit to overt intolerance; the patients treated with plasma exchange (3/3), rituximab (1/1) or corticosteroid (7/12) improved dramatically, with other immumosuppressants and intravenous immunoglobulin partially responsive. Moreover, 5 patients undergoing thymectomy improved markedly or partially.ConclusionsCompared with MG patients with MuSKAb positivity merely, the condition of the double-seropositive MG patients seem to be more severe and further inclined to myasthenic crisis. The incidence of abnormal thymus, such as thymus hyperplasia, is higher. Thymectomy may be an effective treatment for such patients.
Abstract: Objective To investigate the clinical characteristics of thymoma and thymoma with myasthenia gravis(MG). Methods From Oct.1979 to July 2004,185 patients with thymoma were surgically treated. Among these patients, comparative analysis was made between 94 cases of thymoma (thymoma group) and 91 cases of thymus tumor with MG(thymoma with MG group).155 patients underwent radical operation (83.8%),16 patients underwent palliative operation (8.6%),and 14 patients underwent exploratory operation (7.6%). Clinical characteristics was analyzed in two groups. The factors affecting prognosis was analyzed by Masaoka’s stage system, with the lifttable method. Results Five patients died after operation, others had complete remission or symptomatic improvement. There was statistically difference of Masaoka’s stage system in two groups (χ2=53.14, P＜0.05). There were no statistically difference in pathological type of thymoma and clinical type of MG and pathologic period (χ2=8.21, P＞0.05). 57 cases of thymoma group were followed up, the duration of follow-up was 1 to 10 years, average follow-up was 40.7 months, and the patients with 1-, 3- and 5-year survival rates were 70.2% (40/57), 66.7% (22/33), 593% (16/27) respectively. 55 cases of thymoma with MG group were followed up. The patients’ survival rates were 98.2% (54/55), 86.4% (38/44), 81.6% (31/38) at 1-, 3-and 5-year respectively. There was no statistically difference of survival rates in two groups (χ2=0.83, P＞0.05). Totally, 112 patients were followed up in two groups, by Masaoka’s stage system, the 5-year survival rates were 93.7% for stage Ⅰ, 79.2% for stageⅡ, 51.4% for stage Ⅲ and 0% for stage Ⅳ respectively. Result of asaoka’s stage system evidence was statistically significant (χ25-year=51.62, P＜0.01). Conclusions Pathological type of thymoma isn’t related to modified Osserman’s classification, prognosis of thymoma is obviously related to Masaoka’s stage and isn’t related to MG. Generalized MG is the major type in MG patients accompanied by thymomas, and the major pathological type is lymphocytic. Chest CT can increase the accuracy early diagnosis of thymoma. The principal treatment is to resect the tumor as completely as possible, and proper administration of postoperative radiotherapy or chemotherapy according to the surgical status. Operative program and tumor stage are the most important prognostic factors.
Myasthenia gravis (MG) is an autoimmune disease with indefinite pathogenesis. MG is closely related to thymic diseases, and thymectomy is an important way for MG treatment. However, there are some controversies regarding thymectomy, including indications, operation opportunities, operative procedures, surgical approaches, perioperative managements, and efficacy evaluations, etc. Therefore, based on the literature and the experience of Chinese experts, this consensus has been written after careful discussion and inquiry and 29 recommendations have been made, aiming to guide surgical treatment of MG and improve the clinical outcomes.
Objective To investigate application values and techniques of robot-assisted extended thymectomy for the treatment of typeⅠmyasthenia gravis （MG） using Da Vinci S system. Methods We retrospectively analyzed clinical data of 3 patients with MG who underwent robot-assisted extended thymectomy in General Hospital of Shenyang Military Command from March 2012 to September 2012. All the patients were ocular MG （typeⅠ） including 2 men （33 years and 66 years old respectively） and 1 woman （21 years old）. Surgical outcomes were analyzed. Results All the 3 patients successfully received robot-assisted extended thymectomy without accessorial incisions. None of the patients required converting to open sternotomy or postoperative reexploration for bleeding. Intraoperative blood loss was 5-10 ml．Overall operation time was95-138 minutes, and thymoma dissection time was 26-80 minutes. No myasthenic crisis or other major postoperative complic-ation occurred. Postoperative chest drainage duration was 3-9 days and postoperative hospital stay was 10-15 days. Two patientswere followed up for 6-12 months after discharge without MG recurrence. Conclusion Robot-assisted extended thymectomy is safe and feasible for the treatment of typeⅠMG with satisfactory results．
Thymectomy is a major surgical procedure for patients with non-thymomatous myasthenia gravis，and can enhance their symptomatic remission rate and cure rate. There is still much controversy about appropriate surgical approach and extent of resection of thymectomy. The majority of thoracic surgeons believe that the completeness of thymectomy is closely associated with clinical symptom improvement，and perform complete resection of encapsulated thymus and surroun-ding fat tissues via mid-sternotomy. But minimally invasive thymectomies are often more acceptable by patients. On the contrary，in view of common existence of ectopic thymus tissue，some thoracic surgeons advocate a combination of cervical incision and sternotomy in order to further completely remove all thymus tissue.
ObjectiveTo analyze the risk factors for post-thymectomy myasthenic crisis (PTMC) and prolonged mechanical ventilation, in myasthenia gravis patients who underwent extended thymectomy. MethodsWe retrospectively analyzed the clinical data of 79 patients including 38 males and 41 females who experienced PTMC and required mechanical ventilation in Daping Hospital between June 2008 and November 2014. Single factor analysis and multivariate analysis were conducted. ResultsMorbidity of PTMC was 20.6% (79/384). Result of single-factor analysis showed that postoperative pneumonia was one of the main reasons of prolonged mechanical ventilation (P < 0.05). Result of multiple-factor analysis showed that the operation time was positively correlated with mechanical ventilation time (P < 0.05). The risk factor of prolonged mechanical ventilation time in PTMC was not associated with sex, age, disease history, myasthenic crisis history, Osserman classification, dosage of pyridostigmine before and after the operation, surgical approach, bleeding volume, other therapies besides mechanical ventilation (P > 0.05). ConclusionMechanical ventilation is one the main therapy of PTMC, operation time, and postoperative pneumonia are the main factors to prolong mechanical ventilation time. In order to decrease morbidity of PTMC and shorten mechanical ventilation time, the operation time should be controlled and pulmonary infection should be avoided.
ObjectiveTo analyze the risk factors of myasthenia gravis crisis after thymectomy with myasthenia gravis (MG).MethodsSixty-five myasthenia gravis patients who had myasthenia crisis after thymectomy in Xuanwu Hospital, Capital Medical University from June 2006 to June 2019 were retrospectively enrolled, including 31 males and 34 females, aged 15-78 (45.7±17.8) years. The relationship between myasthenia crisis after thymectomy and surgical option, operation time, pathological type, et al. were anylyzed.ResultsOperation time and pathological type were the predictive factors of postoperative myasthenic crisis. The area under receiver operating characteristic curve (AUC) of MG type (Osserman) was 0.676, the cut-off value wasⅡB type, the sensitivity was 37.5%, the specificity was 90.5%, and the Youden’s index was 0.280. The AUC of thymoma stage (Masaoka) was 0.682, cut-off value was stageⅡ, sensitivity was 62.5%, specificity was 66.7%, and Youden’s index was 0.292. The AUC of blood loss was 0.658, the cut-off value was 90 mL, the sensitivity was 87.5%, the specificity was 69.6%, and the Youden’s index was 0.304.ConclusionPreoperative MG classification, pathological type, operation time and blood loss are the risk factors of postoperative myasthenic crisis. Therefore, adequate preoperative preparation, rapid and careful intraoperative operation and active postoperative management can reduce the occurrence of postoperative myasthenic crisis.
Objective To summarize experiences of surgical treatment and long-term results of myasthenia gravis (MG). Methods Two hundred thirty-six patients underwent thymectomy for MG in our department from Jan.1978 to Dec. 2002. The perioperative management, relative factors of postoperative crisis and long-term results were analysed. Results In 236 patients postoperative crisis took place in 44 cases accounted for 18.6%. The occurrence of postoperative crisis was related to preoperative management, modified Osserman clinical classification and combination with thymoma. Three cases died in the postoperative periods. Among them, one died of acute respiratory distress syndrome induced by aspiration and the other died of crisis. The effective rate in 1, 3, 5 years was 84.6%, 91.0% and 89.0% respectively. Conclusions Thymectomy for MG is safe and effective. Delayed extubation could decrease the needs of tracheotomy in patients with high risk factors for postoperative crisis. The partial sternotomy approach is less traumatic but the long-term effects of surgery are identical to those reported by the most authors.
ObjectiveTo assess the long-term efficacy of extended thymectomy in the treatment of myasthenia gravis(MG) and the factors influencing the results. MethodsWe retrospectively analyzed the clinical data of 45 MG patients who underwent extended thymectomy in our hospital from January 2005 through December 2010. There were 11males and 34 females at age of 32.6(16-50) years. The overall effective rate was calculated. Univariate analysis was used to analyze the risk factors including sex, age, Osserman classification, and pathological type for outcomes. ResultsAll the patients were followed up for a mean of 58.3 months(ranged from 36 to 108 months). The overall effective rate was 80.0%(36/45) and rose with the extention of time. Age(P=0.019), pathological type(P=0.024) of thymus and Osserman classification(P=0.043) of MG were the main factors influencing the outcomes of the treatment except sex(P=0.666). ConclusionExtended thymectomy in the treatment of MG has better outcomes. And the overall effective rate rises with the extention of time.