Association of immunosuppression treatment with generalization among patients with ocular myasthenia gravis: A propensity score analysis.

BACKGROUND: To analyze disease generalization in patients with ocular myasthenia gravis (OMG) treated with immunosuppression compared with patients without immunosuppression treatment. METHODS: In this retrospective cohort study, we analyzed data from patients with OMG at seven medical centers in China from January 1, 2015 to May 1, 2019 and compared disease generalization in patients (treated with immunosuppression vs. not treated) within 2 years of disease onset using raw and inverse probability of treatment weighting (IPTW) analyses. RESULTS: In the study population of 813 patients with OMG, 425 (52.3%) with immunosuppression had a mean (SD) onset age of 50.0 (15.1) years, and 188 (44.2%) were women. The remaining 388 (47.7%) patients were not immunosuppressed (mean age, 48.4 [15.0] years; 185 [47.7%] women). Disease generalization developed in 122 (31.4%) and 37 (8.7%) patients in the non-immunosuppression and immunosuppression groups, respectively. Relative to non-immunosuppression, immunosuppression was associated with a lower risk of generalization in a multivariable-adjusted Cox model (hazard ratio [HR] 0.27; 95% confidence interval [CI] 0.18-0.40; p < 0.001) and IPTW-weighted Cox model (HR 0.28; 95% CI 0.19-0.42; p < 0.001). In sensitivity analyses, longer duration of immunosuppression was associated with a lower risk of generalization (HR 0.90 for every 1-month increase; 95% CI 0.87-0.92; p < 0.001; IPTW-adjusted). Combination therapy with steroids and non-steroidal immunosuppressants showed superior efficacy in reducing the risk of generalization (HR 0.14; 95% CI 0.07-0.26; p < 0.001). CONCLUSION: Immunosuppression significantly reduced the 2-year risk of generalization in patients with OMG.

Risk Factors for Generalization in Patients with Ocular Myasthenia Gravis: A Multicenter Retrospective Cohort Study.

INTRODUCTION: Many patients with ocular myasthenia gravis (OMG) progress to generalized disease within the first 2 years of the onset of ocular symptoms. Several retrospective studies have identified risk factors associated with generalization, however these studies included patients on immunosuppression therapy or those undergoing thymectomy, which may reduce the generalization risk. In this study we explored the risk factors for generalization in non-immunosuppressed and non-thymectomized patients with OMG. METHODS: Data from patients with OMG treated at seven tertiary hospitals in China were retrospectively reviewed. Clinical characteristics, including sex, age at onset, symptoms at onset, comorbid autoimmune diseases, neostigmine test response, repetitive nerve stimulation (RNS) findings, presence of serum anti-acetylcholine receptor antibody (AChR-Ab), and thymic status based on radiological and pathological studies, were collected. The main outcome measure was disease generalization. The follow-up period was defined as the date of ocular symptom onset to the date of confirmation of generalization or immunotherapy initiation, or last follow-up (defined as 60 months). The Cox proportional hazards model was used to assess the risk factors for generalization. RESULTS: Overall, 572 patients (269 women) were eligible for inclusion in the analysis, of whom 144 developed generalization. The mean (standard deviation) onset age was 45.5 (19.8) years, and the median (interquartile range) follow-up period was 14.5 (7.0-47.3) months. Multivariable Cox regression analysis demonstrated that both early-onset (adjusted hazard ratio [aHR] 5.34; 95% confidence interval [CI] 1.64-17.36; p = 0.005) and late-onset (aHR 7.18; 95% CI 2.22-23.27; p = 0.001) in adulthood, abnormal RNS findings (aHR 3.01; 95% CI 1.97-4.61; p < 0.001), seropositivity for AChR-Ab (aHR 2.58; 95% CI 1.26-5.26; p = 0.01), and thymoma (aHR 1.62; 95% CI 1.05-2.49; p = 0.03) were independently associated with increased risk of generalization. CONCLUSION: The risk of generalization increased significantly in patients with adult-onset OMG, abnormal RNS findings, seropositivity for AChR-Ab, and thymoma, suggesting that these risk factors may predict OMG generalization.

Thymectomy and Risk of Generalization in Patients with Ocular Myasthenia Gravis: A Multicenter Retrospective Cohort Study.

This study aims to investigate the association between thymectomy and the risk of generalization in patients with ocular myasthenia gravis (MG). Data on patients with ocular MG from seven neurological centers in China were retrospectively reviewed. Ocular MG naïve to immunotherapy was categorized according to whether thymectomy was performed (thymectomized group vs. nonsurgical group). Patients in the thymectomized group all underwent surgery within 2 years since ocular symptom onset. The main outcome measure was the generalization. The follow-up period was defined from the date of ocular symptom onset to the date of generalization confirmation, immunotherapy initiation, or last follow-up (defined as 60 months). Of 519 eligible patients (mean [SD] age, 48.7 [15.2] years, 46.6% women), 31 (23.7%) of 131 generalized in the thymectomized group and 122 (31.4%) of 388 did in the nonsurgical group during a median follow-up of 19 months (IQR 8.0-50.0). Thymectomy was independently associated with reduced generalization risk (adjusted HR 0.41, 95% CI 0.25-0.66, P < 0.001). Multivariable stratified analysis also verified this association across the subgroups. Kaplan-Meier curves showed that the 5-year cumulative rate was significantly lower in the thymectomized group than in the nonsurgical group. To conclude, thymectomy may be considered effective in modifying the progression from ocular to generalized MG irrespective of thymoma.