STUDY OF IL-2, IL-6, TNF-ALPHA, IFN-GAMMA AND IFN-BETA IN THE SERUM AND SYNOVIAL-FLUID OF PATIENTS WITH JUVENILE CHRONIC ARTHRITIS

In the last few years the important role played by various cytokines i n the pathogenesis of chronic inflammatory diseases has emerged. In th e present study, serum and synovial fluid levels of IL-2, IL-6, TNF al pha, IFN beta and IFN gamma were evaluated in a group of 66 patients w ith juvenile chronic arthritis (JCA). At the same time the ESR, CRP, h emoglobin, immunoglobulins, platelet count and Ritchie index were meas ured. In the serum of pauciarticlalar patients, IL-6 and TNF alpha lev els were only slightly elevated compared with controls, but there was no correlation between these cytokines and clinical and other laborato ry parameters. Serum IL-2 and IFN gamma were undetectable. In contrast , in the synovial fluid IL-6 levels were very high in all of the patie nts examined and there was a significant correlation between synovial fluid IL-6 levels and Ritchie's articular index. TNF alpha tended to b e elevated but to a lesser extent, while synovial fluid IL-2 and IFN g amma were undetectable or very low, as in the serum. In polyarticular and systemic patients, on the other hand, serum IL-6 was elevated and statistically correlated with the majority of the laboratory parameter s and with the Ritchie articular index. TNF alpha levels were only sli ghtly elevated; on the other hand IL-2 and IFN gamma were undetectable . There wets art inverse correlation between IFN beta levels and the R itchie articular index and a significant correlation with hemoglobin l evels. In conclusion, our study demonstrates that not only IL-1 (as sh own in other studies), but also IL-6 and to a lesser extent TNF alpha play a central role in the pathogenesis of JCA. IFN beta on the other hand, would seem to play an anti-inflammatory role.