Ultrasound Detects Active Enthesitis, Synovitis While in Remission from PsA

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A new study has found that ultrasound detects non-negligible instances of active enthesitis and synovitis in patients with psoriatic arthritis (PsA) thought to be within the therapeutic target.¹

“Synovitis and enthesitis can exist subclinically, indicating the existence of inflammation which can only be detected by imaging. In this context, the objectives of the study were to evaluate the ultrasound prevalence of enthesitis and active synovitis in a group of PsA patients who reached the therapeutic target under targeted synthetic (tsDMARD), and biological (bDMARD) disease-modifying antirheumatic drugs, as well as to evaluate their agreement with a clinical examination of entheses,” lead investigator Mihaela Agache, Rheumatology Department, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania, and colleagues wrote.¹

The investigators conducted a cross-sectional study including 51 patients with at least 6 months of therapy with b/tsDMARDs who were in treatment target (Disease Activity index for Psoriatic Arthritis [DAPSA] <14). The participants had an average age of 55 years and around half (52.9%) were women.¹

They performed bilateral clinical and ultrasound examinations of the elbow lateral epicondyle, quadriceps insertion, distal patellar tendon insertion, and Achilles enthesis to assess enthesitis, and examined hand and foot joints for synovitis. Active enthesitis and were defined by a power Doppler signal score of at least 1.

Agache and colleagues found that 21.6% of participants had at least 1 painful enthesis at clinical examination, 19.6% had ultrasound evidence of at least 1 active enthesitis, and 15.7% had ultrasound signs of at least 1 active synovitis.¹

Notably, clinical examination of the right lateral epicondyle had a fair agreement with the ultrasound (Cohen’s kappa, 0.3) while clinical examination of the other enthesis sites showed high specificity but low, absent, or incalculable sensitivity when compared to ultrasound. Patients in low disease activity (LDA) remission had a significantly higher prevalence of painful right patellar enthesitis on clinical examination (21.9% compared to none; P = .028) compared to patients in DAPSA-defined remission.¹

Two patients (3.9%) lost the DAPSA treatment target and needed a change in the DMARD strategy after 6 months of follow-up, both of whom had active synovitis at the first ultrasound evaluation. Altogether, defining remission as a power Doppler score of 0, 68% of patients in DAPSA remission were also in ultrasound remission, and 62.5% of patients in DAPSA-LDA were in ultrasound remission.¹

“Psoriatic arthritis is an aggressive inflammatory condition that may lead to irreversible anatomical damage if not adequately treated. The clinical examination may miss mild but active disease, which can be revealed by imaging such as ultrasound. US is the leading imaging method for screening since it can distinguish synovitis, tenosynovitis, dactylitis, and enthesitis. It is quick, non-invasive, non-ionizing, low cost, and can be reassessed numerous times to complete the clinical examination or to evaluate treatment response.” Agache and colleagues wrote.¹

Other recent research on PsA in a cohort of French patients found that initiating targeted therapy) reduced the use of associated symptomatic treatment and healthcare consumption. Initiating targeted therapies decreased the use of non-steroidal anti-inflammatory drugs (NSAIDs; -15%), opioid analgesics (−9%), prednisone (−9%), methotrexate (−15%) and mood disorder treatments (−2%). Hospitalizations (−12%) and sick leaves (−4%) also decreased. Patients receiving TNF inhibitors were slightly more likely to discontinue NSAID (odds ratio [OR], 1.04 [95% CI, 1.01-1.07]) and prednisone use (OR, 1.04 [95% CI, 1.02-1.06]) than those receiving IL17i. On the other hand, those receiving TNFi were slightly less likely to discontinue methotrexate than those receiving IL17i (OR, 0.96 [95% 0.94-0.98]) or IL12/23i (OR, 0.94 [95% CI, 0.92-0.97]).²

REFERENCES

1. Agache M, Popescu CC, Enache L, Mogoșan C, Filippucci E, Codreanu C. Additional Value of Ultrasound in Patients with Psoriatic Arthritis within Treatment Target. J Clin Med. 2024; 13(15):4567. doi: 10.3390/jcm13154567/

2. Vegas LP, Iggui S, Sbidian E, Claudepierre. Impact of initiation of targeted therapy on the use of psoriatic arthritis-related treatments and healthcare consumption: a cohort study of 9793 patients from the French health insurance database (SNDS). RMD Open 2024;10(3):e004631. doi: 10.1136/rmdopen-2024-004631