Myasthenia gravis (MG) is a common antibody mediated, cell-mediated, and complement dependent neuromuscular junction immune disease. The treatment mainly includes drug therapy (symptomatic therapy, non-specific immunosuppressive therapy, targeted immunotherapy), immune regulation (intravenous injection of human immunoglobulin and plasma exchange), and thymectomy. With the continuous deepening of research on MG treatment, targeted immune regulation of B cells, complement system, and neonatal Fc receptors has become a current research hotspot in the treatment of MG. Compared with traditional immunosuppressants, MG patients have better tolerance to new biological agents. This article elaborates on the research of MG targeted therapy related drugs and summarizes their efficacy and safety in MG treatment, aiming to find more treatment options.
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 exploring the effectiveness of perioperative application of new surgical clinical classification and staging for myasthenia gravis (MG) in reducing the incidence of postoperative myasthenic crisis (MC). Methods The clinical data of patients with generalized MG admitted to the Comprehensive Treatment Center for Myasthenia Gravis of Henan Provincial People’s Hospital from January 2018 to June 2022 were retrospectively analyzed, who were scored with myasthenia gravis-activities of daily living (MG-ADL) score and quantification of the myasthenia gravis (QMG) score at the first visit, 1 day before surgery, and 3 days after surgery. The patients were divided into a group A (typeⅡ) and a group B (typeⅢ+Ⅳ+Ⅴ) by the new surgical clinical classification and staging of MG according to the disease progression process, and all patients underwent expanded thoracoscopic thymus (tumor) resection after medication and other interventions to control symptoms in remission or stability. The incidence of MC and the efficiency rate after surgery were analyzed. The normal distribution method and percentile method were used to calculate the unilateral 95% reference range of the QMG score and MG-ADL score. Results Finally 126 patients were enrolled, including 62 males and 64 females, aged 13-71 years, with an average age of 46.00±13.00 years. There were 95 patients in the group A and 31 patients in the group B, and the differences of the preoperative baseline data between the two groups were not statistically significant (P>0.05). The incidence of postoperative MC was 1.05% (1/95) in the group A and 3.23% (1/31) in the group B (P>0.05). The effective one-sided 95% reference range of the QMG score and MG-ADL score 1 day before surgery was 0-7.75 and 0-5.00, and there was no postoperative death in both groups. Conclusion The new surgical clinical classification and staging of MG can guide the timing of surgery, which can benefit patients undergoing surgery for MG and greatly reduce the incidence of postoperative MC.
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.
ObjectiveTo investigate the effect of noninvasive ventilation (NIV) in patients with myasthenic crisis after thymectomy. Methods31 myasthenic crisis patients after thymectomy who initially used NIV,admitted in the First Affiliated Hospital of Guangzhou Medical University between January 2011 and June 2013,were analyzed retrospectively.They were assigned to two groups according to the successful application of NIV or not,with 13 patients in the NIV success group and 18 patients in the NIV failure group.The related factors including gender,age,APACHEⅡ score when admitted to ICU,the results of blood gas analysis before NIV,thymoma or not,the history of myasthenic crisis,the history of chronic lung disease,and minute ventilation accounted for the largest percentage of predicted value (MVV%pred)were analyzed. ResultsThere were no significant differences in age,gender,or APACHEⅡ score between two groups (P>0.05).The PaCO2 in the NIV success group was lower than that in the NIV failure group.The preoperative MVV%pred in the NIV success group was higher than that in the NIV failure group.There were no significant differences between two groups in pH,PO2,thymoma or not,the history of myasthenic crisis,or the history of chronic lung disease (P>0.05).If using the 45 mm Hg as the cut-off value of PaCO2 and 60% as the cut-off value of MVV%pred,the incidence of PaCO2<45 mm Hg and the incidence of MVV%pred>60% were higher in the NIV success group than those in the NIV failure group (84.6% vs.33.3%, P<0.05;100% vs. 55.6%,P<0.05).Logistic regression analysis revealed that PaCO2<45 mm Hg was an independent influence factor for successful application of NIV in patients with myasthenic crisis after thymectomy. ConclusionPaCO2<45 mm Hg can be a predictor of successful application of NIV in patients with myasthenic crisis after thymectomy.For the patients underwent NIV whose PaCO2<45 mm Hg or MVV%pred<60%,the clinician should predict the possibility of failure and prepared for intubation.
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.
ObjectiveA two-sample Mendelian randomization analysis was used to explore the causal associations between four basic body indices (basal metabolic rate, body fat percentage, BMI and hip circumference) and myasthenia gravis (MG). MethodsPooled gene-wide association study (GWAS) data were obtained from large publicly searchable databases, and four basic body indices were selected as the exposure factors and myasthenia gravis as the outcome factors, and single nucleotide polymorphisms (SNPs), which were strongly correlated with the phenotype of the exposure factors, were screened as the instrumental variables, and two-sample Mendelian randomization analyses were performed in order to assess the potential causal relationship between the exposure and the disease. ResultsInverse variance weighting (IVW) analysis showed that increased basal metabolic rate (OR=1.39, 95%CI 1.00 to 1.93, P=0.047), body fat percentage (OR=1.61, 95%CI 1.06 to 2.44, P=0.024), and hip circumference (OR=1.67, 95%CI 1.29 to 2.17, P<0.001) increased the risk of MG. But there was no significant causal relationship between BMI and MG. ConclusionBasal metabolic rate, body fat percentage and hip circumference have a positive causal relationship with MG, while BMI does not have a significant causal relationship with MG.
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．
Objective To present the preliminary clinical experience of robot assisted trans-subxiphoid (extended) thymectomy in patients with thymic neoplasms or myasthenia gravis. Methods A total of 62 patients (34 males and 28 females at an average age of 38±11 years) suffering from thymic neoplasms or myasthenia gravis who underwent robotic (extended) thymectomy via subxiphoid approach were included in our department between August 2016 and August 2017. All of the operation were completed through 4 ports. In details, the observation hole was created just below the xiphoid process, two ports for arm 1 and arm 2 were created below bilateral subcostal arch at the midclavicular line, and trocar for arm 3 was placed in the 5th or 6th intercostal space at the anterior axillary line, respectively. Patients with thymic neoplasms received thymectomy. Patients with myasthenia gravis received extended thymectomy. Results All the patients experienced uneventful operations. The mean operative time was 116.0±34.0 min. The mean intraoperative blood loss was 5.6±4.3 ml. The mean postoperative hospital stay was 4.0±2.2 days. There was no intra-operational massive hemorrhage, mortality, conversion or postoperative complication during the postoperative and follow-up period. Conclusion Robotic trans-subxiphoid thymectomy is safe and feasible, which is a promising technique for extensive application.
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.