Analysis of Clinical Symptoms and Laboratory Profiles in Children with Juvenile Idiopathic Arthritis in Malopolska Region (Poland) in the Years 2007-2010

Background: Juvenile idiopathic arthritis (JIA) is a heterogenic group of chronic inflammatory connective tissue diseases of unknown aetiology in children up to 16 years of age.Aim: The aim of this study was to analyse the incidence, clinical presentation and laboratory findings in children with JIA in Malopolska region.Materials and methods: A retrospective analysis included all children with JIA (N=251) hospitalized in the two reference rheumatology centres covering Malopolska region (Poland), between July 2007 and December 2010.Results: The annual incidence of JIA in Malopolska region was estimated at 9.5 per 100 000 children. Oligoarthritis (54.9%) was the most common category in all age groups with a tendency to decrease with age; from 71.4 % in children aged 1-6 years; 55.7% in aged 7-12 years to 39.3 % in aged 13-16 years. The frequency of polyarthritis and enthesitis-related arthritis was greater in adolescents (29.2 % and 22.5 %, respectively). HLA-B27 antigen and uveitis were most frequently found in children with enthesitis-related arthritis (58% and 18.5 %, respectively).Conclusions: The study suggests the improvement of diagnostic capacity of JIA during the last decade in Poland. In accordance with the existing data diverse clinical presentation of JIA categories and laboratory characteristics were proven