New biomarkers 14-3-3η multiplex autoantibody assay improves axSpA diagnosis, especially in HLA-B27– patients. Combined with CRP & HLA-B27, detection rose to 99% (training) & 91.4% (evaluation). In HLA-B27– cases, 14-3-3η lifted detection to 70.6% & 55%. Abstract 0531 @RheumNow