engleski

The correlation between the level of IL-18 in sinovial fluid of patients with rheumatoid arthritis and disease activity

Interleukin 18 (IL-18), originally described as IFN gamma inducing factor, is a member of IL-1 superfamily and it has previously been shown to be present in the synovium of rheumatoid arthritis (RA) patients. Its role in RA is due to its abilities to increase gene expression for IL-6, iNOS, COX-2 and the matrix metalloproteases in chondrocytes. In these study we investigated if there were any correlations between the concentrations of IL-18 in synovial fluid of 17 patients with RA and present disease activity assessed by Disease Activity Score (DAS28). The parameters of disease activity were as fallows: the number of tender and swollen joints assessed by physician (total of 28 joints), concentration of C reactive protein in mg/L and patient's global assessment of disease activity on Visual analogue Scale on 100 mm. The DAS28 score for each patient was then calculated by formula given by ESCIT. The concentrations of IL-18 were determined by specific ELISA kit in synovial fluid of RA patients. The average concentration of IL-18 in synovial fluid was 2642.1 ± ; 1248.2 pg/ml. The DAS28 ranged from 5.46 to 7.11. We found that there was positive correlation between levels of IL-18 and DAS28 score (R = 0.36) showing IL-18 relationship with disease activity. There was also positive correlation between IL-18 and erythrocyte sedimentation rate (ESR) (R = 0.23) and rheumatoid factor (RF) (R = 0.4). Also it is well known that TNF-alpha has a pathogenic role in RA, and that cyclic adenosinemonophosphate (cAMP) inhibits its production. We measured the concentration of cAMP in synovial fluid of 17 RA patients and the average concentration of cAMP was 0.53 ± ; 0.41 pmol/mL. We found that concentrations of IL-18 and DAS28 were significantly inversely correlated with concentrations of cAMP (R = -0.57 ; R = -0.56). These data show that IL-18 plays important role in pathogenesis of RA (but it is not the only factor). The data on role of IL-18 in RA appears important because IL-18 binding protein maybe soon used for therapy of RA.

IL-18; rhemathoid arthritis; cAMP; DAS28

nije evidentirano