Association of single nucleotide polymorphisms within cytokine genes to juvenile idiopathic arthritis in Czech children

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.