biostudies-literatureCorsten CEAStichting MOVES 'Klimmen tegen MS'Nationaal MS fonds32969https://www.ebi.ac.uk/biostudies/studies/S-EPMC12475448biostudies-literatureUnknown15(1)After a clinically isolated syndrome (CIS), antinuclear antibodies (ANAs) are often measured in diagnostic workup of inflammatory diseases. Although ANAs are associated with systemic lupus erythematosus (SLE), increased prevalence has been observed in multiple sclerosis (MS) with controversial significance. We determined in a prospective cohort study the association of ANAs measured during diagnostic workup with shared MS and SLE risk factors, clinical characteristics and disease course in CIS patients aged 18-65 years. ANA positivity was found in 60/364 (16.5%) participants and associated with female sex (83.3% vs. 67.4%, p = 0.01) and higher anti-EBNA1 IgG titres (median 1450.0 vs. 588.0 U/ml, p < 0.01), compared to ANA-negative participants. ANA-positive participants were more often homScientific reportsAntinuclear antibodies in early multiple sclerosis reflect systemic lupus erythematosus shared risk factors.PMC12475448P2021-001InspiratiebeursWokke BCorsten CEAIkram MKvan Luijn MMMasmanidou DMarques AMSmolders JfalseAntinuclear antibodies in early multiple sclerosis reflect systemic lupus erythematosus shared risk factors.After a clinically isolated syndrome (CIS), antinuclear antibodies (ANAs) are often measured in diagnostic workup of inflammatory diseases. Although ANAs are associated with systemic lupus erythematosus (SLE), increased prevalence has been observed in multiple sclerosis (MS) with controversial significance. We determined in a prospective cohort study the association of ANAs measured during diagnostic workup with shared MS and SLE risk factors, clinical characteristics and disease course in CIS patients aged 18-65 years. ANA positivity was found in 60/364 (16.5%) participants and associated with female sex (83.3% vs. 67.4%, p = 0.01) and higher anti-EBNA1 IgG titres (median 1450.0 vs. 588.0 U/ml, p < 0.01), compared to ANA-negative participants. ANA-positive participants were more often hom2025-01-01T00:00:00Z2025 Sep2026-07-15T12:33:31.315Z2026-07-04T03:12:57.586ZS-EPMC124754484100641410.1038/s41598-025-17254-0