Immune cells and inflammation in Achilles tendon enthesitis of psoriatic arthritis

Stereological Quantification of Immune-Competent Cells in Biopsies From Painful Achilles Tendons of Psoriatic Arthritis Patients With Ultrasonic Verified Enthesitis: An Exploratory Prospective Cohort Study

Observational Odense University Hospital · NCT03248284

This research will look at immune cells and inflammatory markers in Achilles tendon tissue from people with psoriatic arthritis and enthesitis to see if specific cell types relate to pain, imaging, or short-term remission.

Quick facts

Study typeObservational
Enrollment30 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorOdense University Hospital Academic / other
Locations2 sites (Odense and 1 other locations)
Trial IDNCT03248284 on ClinicalTrials.gov

What this trial studies

The IMPAACT project prospectively enrolls 30 patients with psoriatic arthritis who have insertional Achilles tendon pain and ultrasound-confirmed enthesitis. Tendon biopsies from the mid-portion and the entheseal insertion will be analyzed using immunohistochemistry and a stereological technique to characterize and quantify immune-competent cells. Results will be compared with healthy Achilles tendon specimens and with specimens from patients who have chronic non-PsA Achilles tendinopathy. The study will also explore associations between tendon immune cell profiles and three-month pain remission, ultrasound findings, PsA disease activity, tendon protein analyses, cardiovascular risk factors, blood inflammation markers, and fecal microbiota composition.

Who should consider this trial

Good fit: Adults who meet CASPAR criteria for psoriatic arthritis with insertional Achilles tendon pain and ultrasound evidence of enthesitis, and who are willing to undergo a tendon biopsy, are ideal candidates.

Not a fit: Patients without psoriatic arthritis or ultrasound-confirmed Achilles enthesitis, those with complete tendon rupture, or those unwilling or medically unsuitable for tendon biopsy are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the findings could identify immune cell targets or biomarkers that help guide more effective, targeted treatments for Achilles enthesitis in people with psoriatic arthritis.

How similar studies have performed: Direct histological analysis of PsA Achilles entheses is largely novel, although related immunohistochemical methods have informed inflammation in other PsA-affected tissues.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Fulfilling the CASPAR criteria
* Insertional Achilles tendon pain
* Ultrasonic findings of inflammatory disease at the painful Achilles tendon insertion (= enthesitis) defined as abnormally hypoechoic (loss of normal fibrillar architecture) and/or thickened tendon at its bony attachment, seen in two perpendicular planes that may exhibit a Doppler signal or bony changes, including enthesophytes, and erosions.

Exclusion Criteria:

* Other inflammatory rheumatic diseases than PsA
* Ultrasonic signs of complete rupture of the Achilles tendon
* Not wishing to participate or not suited for project evaluation

Where this trial is running

Odense and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Psoriatic ArthritisEnthesitis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.