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Incidence of juvenile idiopathic arthritis in children in Estonia: a prospective population-based study

C Pruunsild1, K Uibo, H Liivamägi

  • 1Department of Paediatrics, Tartu University, Lunini 6 Tartu 51014, Estonia. Chris.Pruunsild@klinikum.ee

Scandinavian Journal of Rheumatology
|April 25, 2007
PubMed

Insights

The incidence of juvenile idiopathic arthritis (JIA) in Estonia is 21.7 per 100,000 children, with a notable increase observed. Human leucocyte antigen (HLA)-B27 may indicate prolonged inflammation in JIA patients.

Area of Science:

  • Rheumatology
  • Pediatrics
  • Epidemiology

Background:

  • Juvenile idiopathic arthritis (JIA) is a significant rheumatologic condition in children.
  • Understanding the epidemiology and clinical characteristics of JIA is crucial for effective management.
  • Previous studies in Estonia using standardized criteria were limited.

Purpose of the Study:

  • To determine the incidence and subtypes of JIA in Estonia.
  • To track the disease course of newly diagnosed JIA patients over two years.
  • To investigate the frequency of specific human leucocyte antigens (HLA) B27, DR1, and DR4 in JIA patients.

Main Methods:

  • A prospective, population-based study was conducted.
  • New JIA cases were registered between 1998 and 2000.
  • Patients were clinically followed for two years, with HLA typing performed.

Main Results:

  • 162 new JIA cases were identified, with a mean annual incidence of 21.7 per 100,000 children (aged 0-15).
  • The incidence rate showed a 3.5-fold increase during the study period.
  • Oligoarthritis was the most common subtype; HLA-B27 positivity was associated with prolonged inflammation markers.

Conclusions:

  • This is the first Estonian population-based epidemiological study of JIA using International League of Associations for Rheumatology (ILAR) criteria.
  • Increased family doctor awareness likely contributed to the rising incidence.
  • HLA-B27 may serve as a predictive marker for chronic inflammation in JIA.
Abstract

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