ECTRIMS 2024 – ePoster

Introduction: The disease course of aquaporin-4 antibody seropositive neuromyelitis optica spectrum disease (AQP4-Ab+ NMOSD) is unpredictable and highly variable.<br/>Objectives/Aims: We aimed to examine relapse-related outcomes in AQP4-Ab+ NMOSD.<br/>Methods: Data from a nationwide retrospective cohort of 66 patients with AQP4-Ab+ NMOSD with a median follow-up time of 99.5 months (interquatile range: 39-188 months) were analysed. Mixed-effects linear and logistic regression models were used to examine associations between: number of relapses and maintenance treatment and expanded disability status scale (EDSS) scores; type of relapse and its effect on the EDSS score changes; type of initial relapse and risk of developing other types of relapses and frequency of relapses; age and relapse severity; and treatment and recovery.<br/>Results: Longer time before initiation of maintenance treatment was associated with higher EDSS scores at the last follow-up. Not receiving relapse treatment was associated with higher EDSS changes during the follow-up period. Brainstem (BS) relapses were the only type of relapses associated with a higher EDSS at follow-up. There was a higher risk of developing optic neuritis (ON) after transverse myelitis (TM) (OR: 3.21, 95% CI: 1.71-6.02; p &lt;0.001) and, to a lesser degree, vice versa (OR: 2.91, 95% CI: 1.64-5.17; p &lt;0.001). There was also a higher risk of BS relapse after TM (OR: 2.79, 95% CI: 1.21-6.43; p = 0.016) and, to a lesser degree, vice versa (OR: 2.40; 95% CI: 1.08-5.31; p = 0.031). ON was the only initial relapse type that was associated with a higher number of relapses at the last follow-up. Higher age and male sex were associated with more severe relapses of TM, and male sex was also associated with worse recovery after ON.<br/>Conclusion: Earlier initiation of maintenance treatment can limit the accumulation of disability in NMOSD. Our findings indicate certain relapse patterns in NMOSD, which can aid the clinician in tailoring patient monitoring and treatment choice.