biostudies-literatureChoi MYNovo Nordisk FoundationMinistry for Health and Welfare, Republic of KoreaNational Institute for Health Research Manchester Biomedical Research CentreArthritis SocietyNCATS NIH HHSNCRR NIH HHSKorea HealthcareCanadian Institutes of Health ResearchCanada Research ChairsCIHRDepartment of Education, Universities and Research of the Basque GovernmentLUPUS UKLupus Foundation of AmericaLondon Hospitals Biomedical Research CentreNational Institute for Health Research (NIHR)NIAMS NIH HHSWellcome TrustGigtforeningenSandwell and West Birmingham Hospitals NHS TrustSinger Family Fund for Lupus Research1143-1150https://www.ebi.ac.uk/biostudies/studies/S-EPMC10066935biostudies-literatureUnknown81(8)<h4>Objectives</h4>A perception derived from cross-sectional studies of small systemic lupus erythematosus (SLE) cohorts is that there is a marked discrepancy between antinuclear antibody (ANA) assays, which impacts on clinicians' approach to diagnosis and follow-up. We compared three ANA assays in a longitudinal analysis of a large international incident SLE cohort retested regularly and followed for 5 years.<h4>Methods</h4>Demographic, clinical and serological data was from 805 SLE patients at enrolment, year 3 and 5. Two HEp-2 indirect immunofluorescence assays (IFA1, IFA2), an ANA ELISA, and SLE-related autoantibodies were performed in one laboratory. Frequencies of positivity, titres or absorbance units (AU), and IFA patterns were compared using McNemar, Wilcoxon and kappa statistics,Annals of the rheumatic diseasesLongitudinal analysis of ANA in the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort.PMC10066935UL1 TR000150A120404Manchester Clinical Research FacilityAR069572NF-SI-0512-10105A1028R01 AR046588P60AR064464RR00046AR043727R01 AR069572Clinical Research Facility in BirminghamUL1 RR025741Systemic Autoimmune Rheumatic Diseases at UniversiA05990MOP-88526R01 AR043727K24-AR-02318Research Chair in Rheumatic Diseases at the UniverNF-SI-0617-100751U54TR001353P60 AR064464UL-1RR-025741K24 AR002138K24 AR002213K24 AR066109P60 AR048098AR046588Gary S Gilkeson Career Development AwardDistinguished Senior Investigator of The ArthritisLim SWallace DJKalunian KPetri MChoi MYDooley MABuyon JPClarke AESanchez-Guerrero JManzi SJonsen AFortin PRFritzler MJPeschken CAlarcon GSRahman ABernatsky SBruce INCostenbader KHGinzler EMRamsey-Goldman RSt-Pierre YRomero-Diaz JGladman DDMerrill JTHanly JBae SCRuiz-Irastorza GAskanase AAranow CUrowitz MGordon CInanc MMackay Mvan Vollenhoven RFIsenberg DKamen DLJacobsen SfalseLongitudinal analysis of ANA in the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort.<h4>Objectives</h4>A perception derived from cross-sectional studies of small systemic lupus erythematosus (SLE) cohorts is that there is a marked discrepancy between antinuclear antibody (ANA) assays, which impacts on clinicians' approach to diagnosis and follow-up. We compared three ANA assays in a longitudinal analysis of a large international incident SLE cohort retested regularly and followed for 5 years.<h4>Methods</h4>Demographic, clinical and serological data was from 805 SLE patients at enrolment, year 3 and 5. Two HEp-2 indirect immunofluorescence assays (IFA1, IFA2), an ANA ELISA, and SLE-related autoantibodies were performed in one laboratory. Frequencies of positivity, titres or absorbance units (AU), and IFA patterns were compared using McNemar, Wilcoxon and kappa statistics,2022-01-01T00:00:00Z2022 Aug2025-04-04T21:09:58.076Z2025-04-04T21:09:58.076ZS-EPMC100669353533803310.1136/annrheumdis-2022-222168