Environmental factors affecting the risk of generalization for ocular-onset myasthenia gravis: a nationwide cohort study.

BACKGROUND: The environmental effects on the prognosis of ocular myasthenia gravis (OMG) remain largely unexplored. AIM: To investigate the association between specific environmental factors and the generalization of OMG. DESIGN: The cohort study was conducted in China based on a nationwide multicenter database. METHODS: Adult patients with OMG at onset, who were followed up for at least 2 years until May 2022, were included. We collected data on demographic and clinical factors, as well as environmental factors, including latitude, socioeconomic status (per capita disposable income [PDI] at provincial level and education) and smoking. The study outcome was the time to the development of generalized myasthenia gravis (GMG). Cox models were employed to examine the association between environmental exposures and generalization. Restricted cubic spline was used to model the association of latitude with generalization risk. RESULTS: A total of 1396 participants were included. During a median follow-up of 5.15 (interquartile range [IQR] 3.37-9.03) years, 735 patients developed GMG within a median of 5.69 (IQR 1.10-15.66) years. Latitude of 20-50°N showed a U-shaped relation with generalization risk, with the lowest risk at around 30°N; both higher and lower latitudes were associated with the increased risk (P for non-linearity <0.001). Living in areas with lower PDI had 1.28-2.11 times higher risk of generalization. No significant association was observed with education or smoking. CONCLUSIONS: Latitude and provincial-level PDI were associated with the generalization of OMG in China. Further studies are warranted to validate our findings and investigate their potential applications in clinical practice and health policy.

Comparison between mono-tacrolimus and mono-glucocorticoid in the treatment of myasthenia gravis.

OBJECTIVE: Use of tacrolimus in mild to moderate myasthenia gravis (MG) is generally limited to glucocorticoid-refractory cases; the advantage of mono-tacrolimus over mono-glucocorticoids is unknown. METHODS: We included mild to moderate MG patients treated with mono-tacrolimus (mono-TAC) or mono-glucocorticoids (mono-GC). The correlation between the immunotherapy options and the treatment efficacy and side effects were examined in 1:1 propensity-score matching. The main outcome was time to minimal manifestations status or better (MMS or better). Secondary outcomes include time to relapse, the mean changes in Myasthenia Gravis-specific Activities of Daily Living (MG-ADL) scores and the rate of adverse events. RESULTS: Baseline characteristics showed no difference between matched groups (49 matched pairs). There were no differences in median time to MMS or better between the mono-TAC group and mono-GC group (5.1 vs. 2.8 months: unadjusted hazard ratio [HR], 0.73; 95% CI, 0.46-1.16; p = 0.180), as well as in median time to relapse (data unavailable for the mono-TAC group since 44 of 49 [89.8%] participants remained in MMS or better; 39.7 months in mono-GC group: unadjusted HR, 0.67; 95% CI, 0.23-1.97; p = 0.464). Changes in MG-ADL scores between the two groups were similar (mean differences, 0.3; 95% CI, -0.4 to 1.0; p = 0.462). The rate of adverse events was lower in the mono-TAC group compared to the mono-GC group (24.5% vs. 55.1%, p = 0.002). INTERPRETATION: Mono-tacrolimus performs superior tolerability with non-inferior efficacy compared to mono-glucocorticoids in mild to moderate myasthenia gravis patients who refuse or have a contraindication to glucocorticoids.