Objective

We tested the association of certain cytokine gene polymorphisms with juvenile idiopathic arthritis (JIA) in Czech Caucasians.

Methods

In a case–control study, genotypes of 130 patients with JIA (63 males, 67 females; age at onset 7.6 ± 4.4 years; 43 oligoarticular, 72 polyarticular, 15 systemic form) were compared with those of 102 healthy unrelated blood donors. Using polymerase chain reaction with sequence-specific primers designed by J Mytilineos, 24 single-nucleotide polymorphisms were tested within 13 different genes for cytokines (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, TNF-α, TGF-1β, INF-γ) and related molecules (IL-1R, IL-1RA, IL-4Rα). Risk was expressed using OR calculated from allelic, genotypic, and phenotypic frequencies, and the P values were corrected for 13 tested molecules.

Results

Two polymorphisms were significantly associated with JIA. The IL4 -1098 G phenotype was present in 10% of cases and 25% of controls (OR = 0.32, CI 95% 0.16–0.67, P corrected = 0.039). The IL-1β +3962 C phenotype was present in 96% of cases and 84% of controls (OR = 4.65, CI 95% 1.64–13.2, P corrected = 0.05). There was also a tendency towards a lower prevalence of the TNF-α -238 A phenotype in cases (5%) than in controls (16%), but it became insignificant after correction for the number of tested molecules.

Conclusions

Our associations with IL-1β or with IL-4 have not been yet reported from other populations.