Sex differences in multiple sclerosis relapse presentation and outcome: a retrospective, monocentric study of 134 relapse events.

Background: Reporting of sex-specific analyses in multiple sclerosis (MS) is sparse. Disability accrual results from relapses (relapse-associated worsening) and independent thereof (progression independent of relapses).
Objectives: A population of MS patients during relapse treated per standard of care was analyzed for sex differences and short-term relapse outcome (3-6 months) as measured by Expanded Disability Status Scale (EDSS) change.
Design: Single-center retrospective study.
Methods: We analyzed 134 MS relapses between March 2016 and August 2020. All events required relapse treatment (steroids and/or plasma exchange). Demographic, disease, and paraclinical characteristics [cerebrospinal fluid (CSF) and magnetic resonance imaging (MRI)] were displayed separated by sex. Multivariable linear regression was run to identify factors associated with short-term EDSS change.
Results: Mean age at relapse was 38.4 years (95% confidence interval: 36.3-40.4) with a proportion of 71.6% women in our cohort. Smoking was more than twice as prevalent in men (65.8%) than women (32.3%). In- and after-relapse EDSSs were higher in men [men: 3.3 (2.8-3.9), women: 2.7 (2.4-3.0); men: 3.0 (1.3-3.6); women: 1.8 (1.5-2.1)] despite similar relapse intervention. Paraclinical parameters revealed no sex differences. Our primary model identified female sex, younger age, and higher EDSS at relapse to be associated with EDSS improvement. A higher immunoglobulin G (IgG) quotient (CSF/serum) was associated with poorer short-term outcome [mean days between first relapse treatment and last EDSS assessment 130.2 (79.3-181.0)].
Conclusion: Sex and gender differences are important in outcome analyses of MS relapses. Effective treatment regimens need to respect putative markers for a worse outcome to modify long-term prognosis such as clinical and demographic variables, complemented by intrathecal IgG synthesis. Prospective trials should be designed to address these differences and confirm our results.
Competing Interests: PT, AV, FW, SM, and PR declare no disclosures relevant to the manuscript. CF received speaker honoraria and/or travel compensation for activities with Biogen, Sanofi Genzyme, Novartis, and Merck and research support from Chiesi, not related to this work. LD received travel grants from Merck, Biogen, Roche, and Bayer Schweiz. She also received speaker’s/advisor honoraria from Biogen, Novartis, Roche, Merck, Lundbeck, Swiss MS Society, and National Swiss Ice Hockey League. She is a member of the Advisory Board of the Swiss MS Society. She also serves as Guest-Co Editor for Brain Sciences (2022/2023) and as Guest-Editor for Journal of Central Nervous System Disease (2022/2023). HH speaker/advisor honorary from Merck, Biogen, Janssen, Teva/Mepha. She received research support within the last 5 years from Biogen. She received travel grants from Biogen, Roche, Janssen, and Merck. RW received speaker/advisor honoraria from Bayer Healthcare, Biogen, Siemens Healthineers. He received research support from Biogen, the Swiss Innovation Agency, the U.S. National Institute of Health, and the Swiss National Foundation. AC received speakers’/board honoraria from Actelion (Janssen/J&J), Almirall, Bayer, Biogen, Celgene (BMS), Genzyme, Merck KGaA (Darmstadt, Germany), Novartis, Roche, and Teva, all for hospital research funds. He received research support from Biogen, Genzyme, and UCB, the European Union, and the Swiss National Foundation. He serves as an associate editor of the European Journal of Neurology, on the editorial board for Clinical and Translational Neuroscience, and as a topic editor for the Journal of International Medical Research. RH received speaker/advisor honorary from Merck, Novartis, Roche, Biogen, Alexion, Sanofi, Janssen, Bristol-Myers Squibb, Teva/Mepha, and Almirall. He received research support within the last 5 years from Roche, Merck, Sanofi, Biogen, Chiesi, and Bristol-Myers Squibb. He also received research grants from the Swiss MS Society and is a member of the Advisory Board of the Swiss MS Society. He also serves as an associated editor for Journal of Central Nervous System disease. AS received speaker honoraria and/or travel compensation for activities with Bristol Myers Squibb, CSL Behring, Novartis, and Roche, and research support by the Baasch Medicus Foundation, the Medical Faculty of the University of Bern, and the Swiss MS Society.
(© The Author(s), 2024.)