Chloroquine therapy in patients with recent-onset rheumatoid arthritis: the clinical response can be predicted by the low level of acute-phase reaction at baseline.

If rheumatoid arthritis (RA) patients with a mild disease course could be identified early in the phase of the disease, therapy with less aggressive and probably less toxic antirheumatic drugs seems to be rational. The aim of this study was to investigate which factors at baseline could predict a clinical response (American College of Rheumatology preliminary response criteria) after treatment with chloroquine for 16 weeks. Two hundred and three early RA patients with active disease were treated with oral chloroquine sulphate (Nivaquine) at a daily dose of 300 mg during the first 4 weeks, 200 mg during the second 4 weeks and 100 mg thereafter. One hundred and eighty-three patients (90%) completed the study and 20 patients prematurely discontinued treatment. Of all the patients, 43 patients (21%) met the response criteria. A low level of C-reactive protein (CRP) was the only independent predictor for clinical response [relative risk: 0.97 (95% confidence interval: 0.95-0.98)]. It was concluded that a clinical response to chloroquine therapy in early RA patients can be predicted by a low CRP level at baseline.