Frequency and duration of clinical remission in patients with peripheral psoriatic arthritis requiring second-line drugs

Objective. To evaluate the frequency and duration of clinical remission in patients with PsA. Methods. All consecutive new outpatients with peripheral PsA requiring second-line drugs and RA observed between January 2000 and December 2005 were included in a prospective, case-control study. Primary end point was to assess the frequency of remission in peripheral PsA compared with RA. Secondary end points were to compare the duration of clinical remission during treatment and after therapy interruption, ACR 20, 50, 70 response rates and to detect any remission predictor at diagnosis. Treatment regimen was standardized in both groups. From January 2003 to December 2005, therapy was suspended in PsA patients and controls if achieving remission. Results. One or more episodes of remission occurred in 57/236 (24.1%) PsA patients and in 20/268 (7.5%) controls (P<0.001). The mean duration of remission was of 13 +/- 9.4 months in PsA patients and 4 +/- 3.7 in controls (P>0.001). Remission episodes were more frequent in PsA patients treated with anti-TNF compared with those receiving traditional DMARDs (P>0.001), with no differences regarding the duration. After therapy interruption, the remission duration was 12 +/- 2.4 months in PsA and 3 +/- 1.5 in RA (P<0.001). No remission predictor at diagnosis resulted by multivariate analysis. Conclusion. Remission is possible in up to 24% of patients with peripheral PsA. It is significantly more frequent, but not longer, in patients receiving anti-TNF drugs compared with those treated with traditional DMARDs. Patients remain in remission for a long period after therapy interruption, thus suggesting an intermittent therapeutic strategy.