title: Course of joint disease in patients with antinuclear antibody-positive juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To describe the patterns and time course of arthritis in patients with antinuclear antibody (ANA)-positive juvenile idiopathic arthritis (JIA).
  
  
  METHODS
  We identified patients followed during a 16-year period who had JIA by ILAR criteria, were ANA-positive (i.e., had >or= 2 positive ANA test results at titer >or= 1:160), and had a disease duration >or= 2 years. Demographic and clinical features, including ILAR category and cumulative number and type of joints affected over time, were recorded.
  
  
  RESULTS
  A total of 195 patients were studied. The ILAR category was oligoarthritis in 159 patients and rheumatoid factor-negative polyarthritis in 36 patients. The cumulative rate of polyarticular extension in patients with oligoarticular onset was 26%, 38%, 45%, 49%, and 51% at 1, 2, 3, 4, and 5 years, respectively. At disease onset, most patients had monoarthritis and 95% had <or= 4 joints affected. The knee was the most frequently involved of all joints, followed by the ankle and proximal interphalangeal joints. Among patients with oligoarticular onset, the presence of ankle (in case of monoarticular disease) and/or wrist involvement in the first 6 months was more common in those who progressed to polyarthritis.
  
  
  CONCLUSIONS
  The majority of our ANA-positive patients, including most of those who later developed polyarthritis, had monoarthritis at disease onset. Among patients with oligoarticular onset, polyarticular extension occurred in around 50% of cases within the first 3-4 years after disease onset, and tended to be less likely thereafter. The early occurrence of ankle and/or wrist disease may indicate a higher likelihood of arthritis progression.
authors.affiliation: Dipartimento di Pediatria, Università di Genova, Unità Operativa Pediatria II, Istituto di Ricovero e Cura a Carattere Scientifico G. Gaslini, Genova, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Felici
authors.forename: Cristina
authors.initials: C
authors.lastname: Novarini
authors.forename: Silvia
authors.initials: S
authors.lastname: Magni-Manzoni
authors.forename: Angela
authors.initials: A
authors.lastname: Pistorio
authors.forename: Alessandra
authors.initials: A
authors.lastname: Magnani
authors.forename: Elena
authors.initials: E
authors.lastname: Bozzola
authors.forename: Antonella
authors.initials: A
authors.lastname: Buoncompagni
authors.forename: Alberto
authors.initials: A
authors.lastname: Martini
authors.forename: Angelo
authors.initials: A
authors.lastname: Ravelli
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000974:Antibodies, Antinuclear / Q000032:analysis / Q000276:immunology*; D001168:Arthritis / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D001171:Arthritis, Juvenile / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007596:Joints / Q000503:physiopathology*; D008297:Male; D010147:Pain Measurement; D011336:Probability; D011379:Prognosis; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D000974:Antibodies, Antinuclear