AB1125

JUVENILE IDIOPATHIC ARTHRITIS ENTHESITIS-RELATED ARTHRITIS (ERA) SUBTYPE: DO BOYS AND GIRLS HAVE A DIFFERENT CLINICAL FENOTYPE AND COURSE?

C. Malagon ^1,*A. C. Mosquera ¹

¹Reumatologia Pediatrica, Universidad El Bosque, Bogota, Colombia

Background: Enthesitis-related arthritis (ERA) is a subtype of juvenile idiopathic arthritis (JIA) according to the International League of Associations for Rheumatology (ILAR) classification. Its frequency varies widely on different populations. It is more frequent among men and has a strong genetic association with HLA-B27. Enthesitis and involvement of peripheral and axial joints are the typical features. The onset and course of the disease varies widely and some patients fulfill diagnostic criteria for ankylosing spondylitis. We search  in a cohort of JIA-ERA patients if there are differences on type of joint involvement ,clinical course and prognosis between female and male patients.

Objectives: Describe the clinical and laboratory differences between male and female patients with juvenile idiopathic arthritis, enthesitis-related subtype in Bogotá, Colombia

Methods: Multicenter, retrospective study was conducted by collecting information on clinical and laboratory features, treatment and course in patients with ERA.

Results: This series includes 106 patients. Mean age at onset 11.2 years (3-15), female patients 12.1 years (6-15) and male patients 10.8 (3-15). Gender distribution Male 2.3: Female 1. Mean time of follow-up 38.9 months (6-120).21.2% had family history of HLA-B27 diseases or sero-negative rheumatoid arthritis; there are four pairs of brothers with ERA. At disease onset 70.8% had oligo-enthesitis, of which 16% had prominent tarsitis and 12% coxitis.7.5% had isolated enthesitis, 16% isolated sacroiliitis, 5.7% isolated coxitis and 8.5% axial and peripheral compromise. Antinuclear antibodies were positive on 20.8% of patients and HLA-B27 in 38.2%. A statistical significant difference was found between girls and boys in relation to the type of onset of the disease,  being more frequent sacroiliitis in female patients (p 0.001) and oligoenthesitis in male patients (p 0.001). Most patients had a chronic course (75.5%) with axial and peripheral involvement during the course of the disease in 51.9%. Female had a higher frequency of axial course and male of peripheral course without statistical significance (p 0.008-p0.006). 13.2% were treated with anti-TNF medications without frequency differences between both genders. At the end of follow-up 6.6% of patients completed criteria for ankylosing spondylitis without significant differences within boys and girls.

Conclusions: There are clinical differences at the onset and course of the disease between male and female patients with JIA-ERA subtype. An early identification of the patients and an appropriated treatment are important and may have prognostic implications.

References: 1.Colbert A. Classification of juvenile spondyloarthritis: enthesitis-related arthritis and beyond. Nat Rev Rheumatol. 2010 August ; 6(8): 477–485

2.De Carvaho HMS, Bartoluzzo AB, Goncalves CR, Braga da Silva JA, Ximenes AC, Bértolo MB. Gender characterization in a large series of Brazilian patients with spondyloarthritis. Clin Rheumatol. 2011 Dec 28

Disclosure of Interest: None Declared