Comparison between full and tapered dosages of biologic therapies in psoriatic arthritis patients: clinical and ultrasound assessment.

The primary objective of this study was to describe and compare clinical and musculoskeletal (MS) ultrasound (US) features between psoriatic arthritis (PsA) patients treated with full and tapered dosage of biologic (b) disease-modified antirheumatic drugs (DMARDs). The secondary objective was to compare clinical and MSUS features between PsA patients treated with bDMARDs with and without concomitant synthetic (s) DMARDs. We evaluated 102 patients with PsA treated with bDMARDs. The bDMARD dosage tapering had been made in patients with a maintained remission or minimal disease activity (MDA) according to their attending rheumatologist and with the patient acceptance. The bDMARD tapering consisted of the following: increase the interval between doses for subcutaneous bDMARDs or reduction of the dose for intravenous bDMARDs. The clinical evaluation consisted of a dermatologic and rheumatologic assessment of disease activity. The presence of B-mode and Doppler synovitis, tenosynovitis, enthesopathy, and paratenonitis was investigated by a rheumatologist blinded to drug dosage, clinical assessments, and laboratory results. Seventy-four (72.5 %) patients received full dosage of bDMARDs and 28 (27.5 %) received tapered dosage. The duration with biologic therapy and with current biologic therapy was significantly higher in patients with tapered dosages (p = 0.008 and p = 0.001, respectively). We found no significant differences between clinical, laboratory, and US variables, both for BM and CD between patients with full and tapered dosage and between patients with and without concomitant sDMARD. Clinical assessment, MSUS variables, and MDA status are similar in patients receiving full and tapered dosage of bDMARDs.