The authors analyze clinical and laboratory data of patients with juvenile idiopathic arthritis (JIA) which could prove useful in early detection of risk patients and could contribute to the classification of JIA. They evaluated retrospectively 185 patients with JIA whose disease lasted for 5–20 years. As to clinical parameters the onset, duration and activity of the disease, radiographic changes, functional impairment and ocular manifestations were evaluated. Some immunological factors were tested. As to genetic factors the authors investigated the polymorphism of the interleukin 1 receptor antagonist gene (IL-1Ra). The results of the investigation confirmed a great heterogeneity of JIA and justification of classification into sub-groups. In two thirds of the patients with JIA the authors confirmed persisting activity of the disease even after many years and in half of the patients slight or medium severe functional affection. The authors found a significantly higher frequency of allele 2 of the gene for IL-1Ra in the whole group with JIA as compared with healthy controls. In the sub-group of oligoarthritis allele 2 was associated with an extended form of oligoarthritis and was thus described as a prognostic indicator of poorer development of the disease. The second prognostic marker for the group of oligoarthritis was the ESR value at the onset of the disease. Chronic uveitis, a serious extraarticular manifestation of JIA, was present most frequently in persisting oligoarthritis and was associated with positive ANA. In 4 out of 16 cases uveitis developed after more than 7 years of JIA duration.

        Key words: juvenile idiopathic arthritis, uveitis, IL-1Ra, polymorphism