Abstract
BACKGROUND: Optimal timing for treatment discontinuation in myasthenia gravis (MG) patients achieving minimal symptom expression (MSE) remains undefined. METHODS: This prospective cohort study enrolled 196 MG patients from the Huashan MG Registry who achieved MSE and subsequently discontinued all treatments. Cox regression was used to identify prognostic factors for relapse. Among these, 20 patients experienced two discontinuation events and were analyzed separately for their second discontinuation. RESULTS: Over a mean follow-up of 111.10 months, 108 patients (55.1%) experienced relapse. Multivariate analysis identified four independent prognostic factors: onset age ≥ 50 years as a risk factor (HR 1.68, 95% CI 1.04-2.70, p = 0.032), and rituximab administration (HR 0.43, 95% CI 0.17-0.89, p = 0.015), treatment duration ≥ 14.3 months (HR 0.54, 95% CI 0.34-0.85, p = 0.008), and time from MSE to discontinuation ≥ 6.1 months (HR 0.51, 95% CI 0.32-0.83, p = 0.007) as protective factors. Infection, fatigue, and psychological stress were common relapse triggers. CONCLUSIONS: Complete treatment discontinuation after MSE in MG carries substantial relapse risk. Individualized discontinuation decisions incorporating younger onset age, prior rituximab use, adequate treatment and consolidation duration may optimize outcomes.