Clinical course of psoriatic arthritis treated with biologics delineated with ultrasonography.

Psoriatic arthritis (PsA) is a chronic, inflammatory articular disease regarded as a specific subtype of psoriasis. Long-term assessment for PsA using ultrasonography has not yet been investigated. The present study was conducted to delineate the changes in articular lesions after the initiation of biologics using ultrasonography, and to provide the evidence of the utility of ultrasonography in long-term follow-up of PsA patients. We retrospectively recruited 17 Japanese PsA patients treated with biologics who met the classification criteria for psoriatic arthritis. Ultrasonographic images were recorded using a high-frequency linear 18 MHz probe through Doppler- and B-modes. Before the treatment with biologics, all examined patients (100%) had enthesitis and extensor tendinitis, while only six patients (35.3%) had loss of the fibrillar pattern of the tendon (LFP). There were significant changes over time in the numerical rating scale score for pain, and in the degree of ultrasonographic findings, including enthesitis, extensor tendinitis, and LFP. Also, there were significant changes over time between these ultrasonographic findings. The study identified the improvement course for a specific PsA lesion after the initiation of biologics. The improvement courses in enthesitis, extensor tendinitis, and LFP were found to differ from each other. These results may contribute to deeper understanding of the pathogenesis of PsA.