The evaluation of effectiveness of IL-17 and IL-23 inhibitors on nail and enthesis involvement in early psoriatic arthritis patients by high-frequency ultrasonography: a single-centre prospective proof-of-concept study.

Purpose: To evaluate the effectiveness of IL-17 and IL-23 inhibitors in psoriatic nail and enthesis involvement by ultrasonography with the use of high-frequency probes (HFUS). To correlate the obtained HFUS findings with disease activity of patients with psoriatic arthritis (PsA).

Material and methods: Consecutive early naïve patients with PsA underwent HFUS on nails and entheses before and after 24 weeks of treatment with IL-17 or IL-23 inhibitor. The Brown University Nail Enthesis Scale (BUNES), considering morphometry and Power Doppler (PD), and the Madrid Sonography Enthesitis Index (MASEI) score were used to evaluate these features. HFUS findings were correlated with the extension of the disease on skin by Psoriasis Area and Severity Index (PASI) and joints by Disease Activity Index for Psoriatic Arthritis (DAPSA).

Results: Twenty early naïve patients with PsA were treated for 24 weeks with an IL-17 or IL-23 inhibitor. A significant reduction of BUNES PD was observed considering the whole cohort of patients receiving these drugs (p = 0.044), whereas, despite a trend, no significant difference was reported comparing BUNES morphometry. The BUNES PD correlated with PASI (r = 0.466, p = 0.030) and with DAPSA (r = 0.444, p = 0.032), whereas BUNES morphometry did not. A significant reduction of MASEI was observed considering the whole assessed cohort of patients treated with these drugs (p = 0.045). The MASEI correlated with both PASI (r = 0.429, p = 0.037) and DAPSA (r = 0.499, p = 0.017).

Conclusions: This proof-of-concept study demonstrated that the assessment by HFUS may provide additional accurate information about the effectiveness of IL-17 and IL-23 inhibitors in psoriatic nail and enthesis involvement.