Active hand inflammation. Differing clinical and ultrasound patterns in patients with rheumatoid arthritis and psoriatic arthritis - A cross-sectional, multicenter study.

OBJECTIVES

To define ultrasound (US) characteristics in patients with Rheumatoid Arthritis (RA) and Psoriatic Arthritis (PsA) exhibiting active hand inflammation.

METHODS

This cross-sectional, multicenter study collected epidemiological and clinical data from RA and PsA patients with active hand inflammation. US examinations of wrists and metacarpophalangeal joints were performed, focusing on extensor and flexor tendons.

RESULTS

A total of 292 patients were included: 192 (61.7%) were women, with a mean age of 56.1 years and mean disease duration of 105.4 months. Ninety-one patients (31.1%) had seropositive RA, 79 (27%) had seronegative RA, and 122 (41.7%) had PsA. Overall, 125 patients (42.8%) exhibited erosive disease, with 103 (35.2%) receiving targeted therapies. All patients had active disease (mean SDAI: 29.5; mean DAPSA: 22.3). Among the cohort, 144 patients (49.3%) showed synovial hypertrophy (SH)≥2+Power Doppler (PD). This was more common in seropositive (72.5%) than in seronegative RA (43%) or PsA (36%) (P≤0.001). Erosive disease (OR 8.4 [3.9-18], P≤0.001) and US global score (OR 1.1 [1-1.1], P≤0.001) were associated with SH≥2+PD. Extensor paratenonitis was more frequent in PsA (27%) compared to seropositive (9.8%) and seronegative RA (18.9%) (P≤0.01). The number of swollen joints (OR 1.1 [1-1.2], P≤0.001) and joint ankylosis (OR 4.3 [1.1-16.9], P≤0.05) were positively associated with paratenonitis.

CONCLUSIONS

Synovial pannus was characteristic of RA, while paratenonitis was more common in PsA. SH≥2+PD correlated with erosive disease, highlighting the need for prospective studies to validate US as a decision-making tool in arthritis.