Anti-CD74 autoantibodies in axial spondyloarthritis as biomarkers for activity and severity of disease but not for tumour necrosis factor inhibitor retention: data from the Swiss Clinical Quality Management in rheumatic diseases cohort.

Objectives: Anti-CD74 antibodies (Abs) have been proposed as a diagnostic biomarker in axial spondyloarthritis (axSpA). The aims of this study were to evaluate the association of these Abs with disease activity parameters in axSpA and to assess their predictive value for tumour necrosis factor inhibitor (TNFi) treatment effectiveness.

Methods: Patients diagnosed with axSpA in the Swiss Clinical Quality Management registry with available biosamples and a measurement of IgA anti-CD74 Abs were included in this cohort study.