Background The diagnostic relevance of HLA B27 for spondyloarthritis (SpA) is well established and highlighted by its inclusion in the classification criteria. However, the clinical relevance of this gen on the disease manifestations is unclear.

Objectives To investigate the influence of HLA B27 status on disease manifestations in patients with recent-onset SpA.

Methods Baseline database from ESPeranza cohort (<45 years, symptoms duration 3–24 months and with inflammatory back pain or asymmetrical arthritis or spinal/joint pain plus ≥1 SpA features) was used. Inclusion period in the program was 2008–2011. For this study, 377 fulfilling the ASAS classification criteria for SpA were included. A descriptive analysis was used to compare demographic and clinical characteristics between HLA B27+ and HLA B27- patients for both subgroups, axial SpA and peripheral SpA. Chi- square test for qualitative variables and Student-t test for quantitative variables were employed to compare variables among groups.

Results A total of 291 patients (75% B27+ and 25% B27-) were classified as axial SpA and 86 (33% B27+ and 67% B27-) as peripheral SpA. Results (mean –standard deviation- and relative frequencies) are presented in the table. In axial SpA, B27+ patients were younger, more frequently males and with a family history of SpA while B27- patients had more frequently psoriasis, IBD and poorer quality of life. In peripheral SpA, B27- had more frequently psoriasis and reported higher BASDAI.

Conclusions In patients with SpA, HLA B27 status influences on the presentation of the disease. In axial SpA, the presence of B27 is associated with an earlier onset, male predominance and more frequency of family history of SpA. In peripheral SpA, the presence of B27 is linked with lower subjective parameters of disease activity. In both, axial and peripheral SpA, the absence of B27 is associated with psoriasis, IBD and poor quality of life.

Disclosure of Interest None declared