HLA-B27 positive patients differ from HLA-B27 negative patients in clinical presentation and imaging: results from the DESIR cohort of patients with recent onset axial spondyloarthritis.

International audienceOBJECTIVE: To clarify the influence of human leucocyte antigen B27 (HLA-B27) status on the phenotype of early axial spondyloarthritis (SpA). METHODS: 708 patients with inflammatory back pain (IBP) defined by Calin or Berlin criteria were recruited; 654 fulfilled at least one of the SpA criteria (modified New York, European Spondyloarthropathy Study Group, Amor or Assessment of SpondyloArthritis international Society classification criteria for axial SpA) and were included in the analyses. Clinical, demographic and imaging parameters were compared between HLA-B27 positive and negative groups. Significant parameters in univariate differences between HLA-B27 positive and negative groups were retested in multivariate models explaining various outcomes. RESULTS: Patients had a short duration of axial symptoms (mean 1.5 years) and HLA-B27 was present in 61.5%. In multivariate analysis, HLA-B27 positivity was associated with a younger age at onset of IBP (regression coefficient (B)=(-2.60), p<0.001), less delay in diagnosis (B=(-1.02), p=0.01), lower frequency of psoriasis (OR 0.59, p=0.01) and higher frequency of MRI inflammation of the sacroiliac joints (SIJ) (OR 2.13, p