SERUM-SOLUBLE INTERLEUKIN-2 RECEPTOR LEVELS IN RHEUMATOID-ARTHRITIS -EFFECT OF METHOTREXATE, SULFASALAZINE AND HYDROXYCHLOROQUINE THERAPY

The aim of this study was to assess the correlations of the serum solu ble interleukin 2 receptor (sIL-2R) concentrations with disease activi ty parameters and response to treatment with second line drugs in pati ents with rheumatoid arthritis (RA). Sixty-seven patients with active disease completed a 24-week, open, randomized study of methotrexate (M TX) versus sulphasalazine (SSZ) or hydroxychloroquine (HCQ). Serum sIL -2R levels were evaluated before entry and after 24 weeks by ELISA. Se rum sIL-2R were significantly higher in RA patients than in controls ( P=0.0001) and correlated significantly only with erythrocyte sedimenta tion rate (P=0.03) and with Chronic Arthritis Systemic Index (P=0.01) at study entry. No correlation was found between serum sIL-2R and othe r laboratory and clinical indices of disease activity. After 24 weeks of treatment no differences in serum sIL-2R in comparison with basal l evels were found in either responding or in non-responding patients, a lthough the mean reduction of sIL-2R was more marked in the MTX-treate d cohort than in the HCQ and SSZ-treated groups, These data suggest th at in RA the measurement of sIL-2R should be used with caution as an i solated index of disease activity and that it is not a useful marker o f response to treatment with second line drugs.