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Introduction Autoantibodies against NOR-90 are rare and have been associated with systemic sclerosis (SSc). This study seeks to identify the characteristics of SSc participants with anti-NOR-90 autoantibodies.Material and Methods An international (Canada, Australia, USA, Mexico) cohort of 2143 SSc participants were included assembled. Sera were tested using a line immunoassay (Euroimmun, Luebeck, Germany). Clinical associations with anti-NOR-90 autoantibodies were investigated. Single-specificity anti-NOR-90-positive was defined as anti-NOR-90-positivity without other SSc-related autoantibodies, except for anti-Ro52/TRIM21.Results 115 (5%) participants were anti-NOR-90-positive, of whom the majority overlapped with other autoantibodies. Anti-NOR-90 positivity overall was associated with a higher frequency of calcinosis (35% vs 24%, OR 1.70, 95% CI: 1.13, 2.52), digital ulcers (62% vs 49%, OR 1.70, 95% CI: 1.12, 2.61) and arthritis (37% vs 29%, OR 1.61, 95% CI: 1.06, 2.40). Single-specificity anti-NOR-90-positive participants (n=21) had lower mRSS (4.0 vs 7.0, beta =-3.66, 95% CI: -7.95, 0.63), a higher frequency of pulmonary hypertension (37% vs 14%, OR 3.58, 95% CI: 1.32, 9.00), lower mean % predicted forced vital capacity (FVC, 82.0% vs 91.3%, beta=-9.36, 95% CI: -18.40, -0.33) and diffusion capacity (DLCO, 58.9% vs 69.0%, beta=-10.10, 95% CI: -10.05, -0.15) and higher frequency of interstitial lung disease (52% vs 34%, OR 2.11, 95% CI: 0.89-5.09). Anti-NOR-90 autoantibodies were not associated with increased cancer (10% vs 8%) or mortality (adjusted HR 1.27, 95% CI: 0.86, 1.88).Conclusions In this large multicentre cohort, anti-NOR-90 autoantibodies commonly overlapped with other SSc-autoantibodies. Single-specificity anti-NOR-90 positivity was associated with lower mRSS but more frequent pulmonary abnormalities.Key messagesAnti-NOR-90 autoantibodies in SSc commonly overlapped with other SSc-autoantibodies, which likely impacted disease associations.Single-specificity participants had lower mRSS, more pulmonary hypertension, and lower % predicted DLCO and FVC.Despite reports of anti-NOR-90 associations with cancer, no association was found in this SSc cohort.Abstract P.054 Figure 1Overlapping autoantibodies in 2143 systemic sclerosis participants according to anti-NOR-90 autoantibody status