DECREASE OF INTERLEUKIN-6 DURING THE FIRST 12 MONTHS IS A PROGNOSTIC MARKER FOR CLINICAL OUTCOME DURING 36 MONTHS TREATMENT WITH DISEASE-MODIFYING ANTIRHEUMATIC DRUGS

The aim of this study was to determine prognostic markers for the outc ome after 36 months of therapy with disease-modifying anti-rheumatic d rugs (DMARDs) in patients with rheumatoid arthritis (RA) and to study serial cytokine serum levels. During 36 months, 20 patients receiving DMARDs (nine patients gold sodium thiomalate and 11 patients methotrex ate, no comparison undertaken) were followed for clinical and laborato ry data. Investigation at baseline, 12, 24 and 36 months, included cli nical, radiological and laboratory parameters such as erythrocyte sedi mentation rate (ESR) and C-reactive protein (CRP), and interleukin (IL )-1 beta, IL-6, tumour necrosis factor alpha (TNF-alpha), IL-1 recepto r antagonist (IL-1RA) and IL-2. During the 3 yr of therapy, the patien ts showed significant clinical improvement and decline of ESR, CRP, an d serum levels of IL-6 and IL-2. The decrease in IL-6 serum levels dur ing the first year of therapy correlated significantly with the decrea se, after 36 months, in the number of inflamed joints (r = 0.7608, P < 0.005), Lansbury index (I = 0.6642, P < 0.005) and morning stiffness (r = -0.6561, P < 0.005). In contrast to IL-6 or IL-2, TNF-alpha and I L-1RA did not vary significantly during the 3 yr of therapy. During 36 months of therapy, patients treated with DMARD showed significant imp rovement of clinical parameters and a trend for delayed progression of radiographic damage. The decrease in IL-G concentration in serum duri ng the first 12 months was the best prognostic marker for the clinical outcome after 36 months of DMARD therapy.