RT Journal Article SR Electronic T1 Clinical Features of Late-onset Ankylosing Spondylitis: Comparison with Early-onset Disease JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1008 OP 1012 DO 10.3899/jrheum.111082 VO 39 IS 5 A1 CARLOS MONTILLA A1 JAVIER DEL PINO-MONTES A1 EDUARDO COLLANTES-ESTEVEZ A1 PILAR FONT A1 PEDRO ZARCO A1 JUAN MULERO A1 JORDI GRATACÓS A1 CARLOS RODRÍGUEZ A1 XAVIER JUANOLA A1 JOSE LUIS FERNÁNDEZ-SUEIRO A1 RAQUEL ALMODOVAR A1 the REGISPONSER Study Group YR 2012 UL http://www.jrheum.org/content/39/5/1008.abstract AB Objective. Ankylosing spondylitis (AS) is generally observed in young patients but can occur later in life or in persons ≥ 50 years of age. Our objective was to characterize the clinical features of late-onset AS in a large multicenter national cohort. Methods. We studied late-onset AS in the National Registry of Spondyloarthritis of the Spanish Society of Rheumatology (REGISPONSER database) cohort (n = 1257), of whom 3.5% had onset at age ≥ 50 years versus a control group with onset at < 50 years. Results. There were no differences between late-onset and early-onset AS according to sex and family history of spondyloarthropathies. Patients in the late-onset group more often showed involvement of the cervical spine (22.7% vs 9.7%; p = 0.03) and arthritis of the upper (13.6% vs 3.0%; p = 0.002) and lower limbs (27.3% vs 15.2%; p = 0.03) as first manifestations than did patients in the early-onset group. A higher percentage of mixed forms (axial and peripheral joint disease) during the course of the disease was also recorded in the late-onset group (50% vs 24%; p = 0.0001). Conclusion. Our study suggests that age at onset of AS affects the patients’ presenting clinical form. Arthritis of the upper limbs requires a differential diagnosis with other conditions frequent in patients over 50 years of age, such as rheumatoid arthritis or crystal-induced arthropathy.