HLA-B27 frequency in a group of patients with psoriatic arthritis.

BACKGROUND: HLA-B27 is associated with spondyloarthritis, a group of diseases that includes psoriatic arthritis. OBJECTIVES: To describe the HLA-B27 frequency in a group of Brazilian patients with psoriatic arthritis and correlate its presence or absence with their clinical manifestations. METHODS: Cross-sectional study with 44 psoriatic arthritis patients of a Rheumatology clinic. Demographic and social data were recorded, as were skin and joints clinical examination. HLA-B27 was tested. All data were processed descriptively and comparatively by appropriate software. Parametric and non parametric tests were used with 5% statistical significance. RESULTS: HLA-B27 was negative in 32 of the 44 patients (72,7%). Most of them were male, Caucasian, living in Rio de Janeiro, with plaque type psoriasis and average age of 52,9 years. There was statistical significant correlation between positive HLA-B27 and male gender (p=0,004). Negative HLA-B27 had a tendency to correlate with hands and wrists arthritis (p=0,07). There was an inverse significant correlation between HLA values and Schöber's test (p=0,02). CONCLUSION: Although HLA-B27 is negative in most of patients, it is significantly associated to male gender and inversely correlated with Schöber's test.