In patients with psoriatic arthritis (PsA), the use of power Doppler (PD) signal and bone erosions at the enthesis are highly relevant sonographic biomarkers of more severe disease at the joint level, according to study results published in The Journal of Rheumatology.
In a cross-sectional study, the researchers sought to explore the association of the Outcome Measures in Rheumatology (OMERACT) ultrasound entheseal abnormalities with the presence of ultrasound joint bone erosions in patients with PsA.
Enthesitis is one of the hallmarks of PsA and is part of the Classification Criteria for Psoriatic Arthritis (CASPAR) criteria. According to the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), enthesitis is 1 of the 6 clinical domains to be considered in the treatment of patients with PsA.
Demographic and clinical parameters were collected from all participants. A bilateral ultrasound assessment was performed at the plantar fascia, quadriceps, patellar (proximal and distal), and Achilles tendons. The ultrasound entheseal abnormalities that were registered included hypoechogenicity, thickening, Doppler signal less than 2 mm from the bony cortex, calcification/enthesophyte, and bone erosion. The presence of ultrasound joint bone erosions was determined at the second and fifth metacarpophalangeal (MCP) joints, the ulnar head, and the fifth metatarsophalangeal (MTP) joint, both bilaterally and at the level of the most inflamed joint on physical examination.
Researchers conducted the study among consecutive patients aged 18 years and older with PsA who were enrolled at the Rheumatology Unit of “Carlo Urbani” Hospital, Jesi, in Ancona, Italy, between June 2020 and February 2021.
A total of 104 patients with PsA were included, with 1040 entheses evaluated. The most common finding was calcification/enthesophyte with 1 or more entheses affected in 96.1% (n=100) of patients, followed by hypoechogenicity in 89.4% (n=93), thickening in 77.9% (n=81), PD signal in 55.8% (n=58), and bone erosion in 23.1% (n=24).
Study findings showed that 1 or more joint bone erosions was detected in 45.2% (n=47) of the participants. Bone erosions were commonly detected at the fifth MTP joint level (20.2% of the joints; 30.8% of participants).
In a multivariable model, only PD signal at the enthesis (P <.001), bone erosions at the enthesis (P =.02), duration of PsA (P =.04), and greyscale joint synovitis (P =.03) were significantly associated with ultrasound-detected joint bone erosions.
A major limitation of the current study was the fact that a relatively limited number of joints were included in the scanning protocol and that only large entheses were evaluated.
The researchers concluded, “Such findings represent potential key elements for stratification of [patients with] PsA.”
Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Smerilli G, Cipolletta E, Destro Castaniti GM, et al. Doppler signal and bone erosions at the enthesis are independently associated with ultrasound joint erosive damage in psoriatic arthritis. J Rheumatol. Published online February 1, 2022. doi:10.3899/jrheum.210974