Serum IL-2 level in rheumatoid arthritis: correlation with joint destruction and disease progression

Understanding of T cell dysfunctions in rheumatoid arthritis (RA) may help to elucidate the pathophysiology of this disease. Cytokines determinations may be a promising approach and could represent a simple mean of quantifying RA immunological dysfunctions. In this study, interleukin-2 (IL-2) measurements were performed in sera of 74 RA patients to evaluate the potential use of this method to monitor "disease activity" and/or prognosis. Although the serum IL-2 levels of patients in active disease stage proved to be somewhat lower than those from patients with inactive disease, the difference was not significant. In our study, however, the serum IL-2 concentration was correlated with the circulating immune complexes level. In addition, patients with the highest serum IL-2 levels exhibited the poorest radiological stages and these same patients were often not receiving any disease modifying antirheumatic drugs (DMARD). Our results demonstrate that serum IL-2 level may be elevated in certain RA conditions. A better understanding of this phenomenon, especially the consequences of disease duration, could be of interest in the follow up and the prognosis of the disease.