Introduction: Myasthenic crisis (MC) is a life-threatening condition usually occurred in patients with myasthenia gravis (MG). Objective: On the basis of a retrospective case series review, we try to develop a scoring system to evaluate the probability for in-hospital death in MC patients. Methods: We retrospectively reviewed 78 MC patients who were hospitalized from January 2014 to December 2018. Clinical and laboratory data including 17 variables were analyzed univariately. The main clinical outcome was defined as the in-hospital death. Then eligible variables were evaluated by a stepwise multivariate regression and a scoring system was then generated. Calibration and discrimination methods were used to evaluate and validate the model performance. Results: The overall in-hospital mortality was 11.5% (9/78) in the MC cohort. Five clinical variables including Myasthenia Gravis Foundation of America (MGFA) classification at onset, septic shock, thymoma classification, cardiac arrest, and the lowest serum albumin were found to be associated with in-hospital mortality. Further 3 variables entered the final regression, and internal validation showed that the area under the curve was 0.919 (95% CI 0.788–1.000). A scoring system with a full credit of 7 points was generated to predict the in-hospital mortality (MGFA at onset, 2 points; septic shock, 4 points; and cardiac arrest, 3 points). Conclusions: A 7-point scoring model was established on the basis of a retrospective review of MC patients to predict the in-hospital mortality.

Introduction: The conversion rate from ocular myasthenia gravis (OMG) to generalized myasthenia gravis (GMG) was reported to be much lower in Asian population since most OMG patients are juvenile onset. However, the exact conversion rate for adult-onset OMG to GMG is still unknown. Objective: We aimed to delineate the conversion rate and risk factors for adult patients with ocular onset to GMG. Methods: Adult myasthenia gravis (MG) patients with ocular onset (age > 18 years) were retrospectively reviewed. Patients with confined ocular involvement lasting more than 2 years (pure OMG group) and those who converted into GMG (converted OMG group) were enrolled for subsequent analysis. We then analyzed 5 clinical variables, including onset age, sex, onset symptoms, anti-acetylcholine receptor antibody (AChR Ab), and thymus CT. Survival analysis was applied to all enrolled patients to explore risk factors associated with conversion. Results: In a total number of 249 ocular-onset MG patients initially enrolled, we excluded 122 patients with OMG lasting less than 2 years. The remaining 127 patients were enrolled, including 106 converted OMG and 21 pure OMG patients. Converted OMG patients had an older onset age (threshold: 43 years) and higher anti-AChR Ab titer (threshold: 6.13 nmol/L). The estimated conversion rate was 70.64%. Moreover, 67% of conversion occurred within 2 years after onset. Cox regression of survival analysis revealed that higher anti-AChR Ab titer and bilateral ptosis were associated with a higher conversion rate. Conclusions: The conversion of adult OMG was associated with anti-AChR Ab titer, onset age, and bilateral ptosis. The estimated conversion rate of Chinese adult OMG patients was 70%.

Introduction: The phenomenon of coexisting autoimmune diseases (ADs) in patients with myasthenia gravis (MG) has attracted considerable attention. However, few studies have investigated the burden and potential clinical associations of ADs in Chinese MG cohorts.Methods: In this retrospective cross-sectional study, we reviewed the records of 1,132 patients with MG who were admitted to Huashan Hospital Fudan University from August 2013 to August 2020. Patients were excluded if they had incomplete medical records (n = 336).Results: Comorbid ADs were found in 92 of 796 Chinese patients with MG (11.6%), among which, hyperthyroidism (6.7%), hypothyrosis (2.6%), and vitiligo (0.8%) were predominant. Patients with MG with ADs were predominantly female, younger at the onset of MG symptoms, and had a lower frequency of thymoma. Compared to the general population, we found a significantly higher percentage of hyperthyroidism (8.5-fold increase, p < 0.001), hypothyrosis (2.6-fold increase, p < 0.001), vitiligo (1.3-fold increase, p < 0.001), rheumatoid arthritis (1.4-fold increase, p < 0.001), immune thrombocytopenic purpura (193.1-fold increase, p < 0.001), autoimmune hemolytic anemia (7.4-fold increase, p < 0.001), autoimmune hepatitis (5.1-fold increase, p < 0.001), and polymyositis (11.5-fold increase, p < 0.001) in patients with MG with ADs. Patients with MG with ADs presented a lower proportion of previous history of MC (0 vs. 5.6%, p < 0.05) than those without ADs. The proportion of MGFA Class I at onset in patients with MG with ADs was significantly higher than that in patients with MG without ADs (77.0 vs. 52.7%, p < 0.05). The proportion of MuSK-positive in patients with MG with ADs was significantly lower than that in patients with MG without ADs (0 vs. 4.8%, p < 0.05).Conclusion: In conclusion, we observed a higher frequency of concurrent ADs in a Chinese MG cohort. Furthermore, MG combined with ADs tended to have mild clinical presentation.