title: Undifferentiated spondyloarthritis in a heterogeneous Brazilian population: an eight-year follow-up study.
abstract: The aim of the present study was to describe the outcomes of Brazilian patients with undifferentiated spondyloarthritis during an eight-year follow-up period. Patients fulfilling the European Spondyloarthritis (SpA) Study Group Classification Criteria were enrolled. Forty patients were seen at baseline, and 36 participated in the follow-up study. Twenty-three (58%) were female, and there were 24 (60%) African Brazilians enrolled. HLA-B27 was positive in 18 (45%) patients. At disease onset, the first presenting symptoms were pure peripheral manifestations in 26 (72.2%) patients. After the study period, mixed disease (axial + peripheral) predominated occurring in 25 (69.4%) patients. The Assessment of SpA International society (ASAS) classification criteria for axial SpA were fulfilled by 77% of patients, and the ASAS criteria for peripheral SpA were fulfilled by 59% of patients. After 2.5 years, 6 (16.7%) of the 36 patients fulfilled the modified New York Criteria for ankylosing spondylitis and 1 (2.7%) progressed to psoriatic arthritis. A total of 10 (27.8%) patients progressed to definite SpA during the eight-year study period. Buttock pain (p = 0.006, OR 10.55; 95% CI 2.00-65.90) and low-grade radiographic sacroiliitis (p = 0.025, OR = 11.50; 95% CI 1.33-83.39) at baseline were associated with definite SpA. Thus, in this Brazilian cohort, which had a predominance of female African-Brazilian patients, prevalent peripheral onset symptoms were followed by a high frequency of axial manifestations during the follow-up period. Evidence of clinical or radiological sacroiliitis was associated with progression to definite SpA.
authors.affiliation: Unit of Rheumatology, Department of Locomotor System, Federal University of Minas Gerais, Av. Brasil, 248/sala 705, Belo Horizonte, MG, 30140-001, Brazil, ricolage@gmail.com.
authors.forename: Ricardo
authors.initials: R
authors.lastname: da Cruz Lage
authors.forename: Carlos Alexandre
authors.initials: CA
authors.lastname: de Souza Bomtempo
authors.forename: Adriana Maria
authors.initials: AM
authors.lastname: Kakehasi
authors.forename: Marco Antônio Parreiras
authors.initials: MA
authors.lastname: de Carvalho
mesh_terms: D000293:Adolescent; D000328:Adult; D015535:Arthritis, Psoriatic / Q000208:ethnology* / Q000628:therapy; D001938:Brazil / Q000453:epidemiology; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index; D025241:Spondylarthritis / Q000208:ethnology* / Q000628:therapy; D013167:Spondylitis, Ankylosing / Q000208:ethnology* / Q000628:therapy; D055815:Young Adult