Understanding of Rare Inflammatory Arthritis in Comparison to Classical Inflammatory Arthritis : Tissular Observations and Immune Infiltrate Characterization : the UTOPIC Project (UTOPIC)

The pathophysiology of certain inflammatory arthritides remains poorly understood, particularly when associated with rare systemic autoimmune diseases such as systemic sclerosis (SSc), or when emerging in the context of immune-related adverse events from cancer immunotherapies. These immunotherapy-induced arthritides represent a new and increasingly encountered clinical entity in rheumatology. A deeper understanding of the mechanisms underlying joint inflammation in these settings is essential for identifying specific therapeutic targets, especially given the limitations of current treatment options and the risks associated with broad immunosuppressive strategies such as prolonged corticosteroid use, which may impair anti-tumor immune responses.

Synovial biopsy analysis provides a powerful tool for dissecting the cellular and molecular components of joint inflammation, including immune cell infiltration, cytokine profiles, and cell-cell interactions. Advances in high-dimensional techniques such as multiplex immunofluorescence and mass cytometry now allow for the identification and spatial localization of numerous protein markers at the subcellular level. Additionally, spatial transcriptomics offers complementary insight into gene expression profiles within the tissue microenvironment, providing a comprehensive understanding of inflammatory processes.

The investigators propose a prospective, proof-of-concept study to characterize and compare rare and emerging inflammatory arthritides-including those linked to SSc and immunotherapy-related immune toxicity-with classical inflammatory rheumatic diseases such as rheumatoid arthritis (RA), psoriatic arthritis (PsA), spondyloarthritis (SpA), polymyalgia rheumatica (PMR), and reactive arthritis. Through detailed immunological and molecular profiling, this study aims to identify disease-specific signatures and novel therapeutic targets. These findings could pave the way for precision medicine approaches and inform the development of targeted therapies in both rare and common forms of inflammatory arthritis.

Study Overview

• Status: Recruiting
• Conditions: Inflammatory Arthritis; Rare Auto-immune Diseases; Immune Checkpoint Inhibitor Related Inflamamtory Arthritis
• Intervention / Treatment: Procedure: Biopsy

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alice Tison, Dr; Phone Number: +33(0)298347264; Email: alice.tison@chu-brest.fr

Study Locations

• France
  • Bordeaux, France, 33404
    • Not yet recruiting
    • Chu Bordeaux
    • Contact: Marie-elise Truchetet, professeur; Phone Number: +(0) 0556794919; Email: Marie-elise.truchetet@chu-bordeaux.fr
  • Brest, France, 29200
    • Recruiting
    • CHU Brest - Hopital Morvan
    • Contact: Alice Tison, Dr; Phone Number: + 33 (0)2 98 34 72 64; Email: alice.tison@chu-brest.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• For all participants:

  • Signed consent form
  • Patients over 18 years old
  • Affiliated with a social security scheme

• For cases:

  • Referred for arthritis or bursitis occurring in the context of a rare systemic autoimmune disease (SAID) or drug-induced toxicity.
  • Presenting at least one clinical arthritis with synovial thickening confirmed by ultrasound (grade ≥2 in B-mode) and Doppler inflammation of grade ≥1, or synovial thickening ≥B2 associated with joint effusion.

For bursitis: thickening ≥2mm of at least one periarticular bursa on ultrasound associated with Doppler inflammation of grade ≥1, or synovial thickening ≥2mm associated with joint effusion, with clinical evidence of inflammatory involvement.

*For the control group:

For arthritis:

• Presenting clinical arthritis with synovial thickening confirmed by ultrasound (grade ≥2 in B-mode (B2)) and Doppler inflammation of grade ≥1, or synovial thickening ≥B2 associated with joint effusion.
• Diagnosed, according to disease-specific classification criteria, with either rheumatoid arthritis (according to ACR/EULAR 2010 criteria), axial or peripheral spondyloarthritis (according to ASAS 2009 criteria), psoriatic arthritis (according to CASPAR criteria), or reactive arthritis based on clinician assessment.

For bursitis:

• Thickening ≥2mm of at least one periarticular bursa on ultrasound associated with Doppler inflammation of grade ≥1, or synovial thickening ≥2mm associated with joint effusion.
• Meeting the ACR/EULAR 2012 criteria for polymyalgia rheumatica.

Exclusion Criteria:

• For all participants:

  • Patients under protective measures or unable to consent
  • Pregnant or breastfeeding women
  • Anticoagulant treatment: vitamin K antagonists (Coumadin, fluindione), direct oral anticoagulants (Eliquis, Pradaxa, Rivaroxaban), heparins at curative doses
  • Contraindication to local procedure: lymphedema near the joint, chronic wound at the site of the joint, joint prosthesis on the affected joint, corticosteroid infiltration less than 3 months ago at the same site
  • History of treatment with biotherapy or targeted therapy (JAK inhibitors) within the last 3 months, or within the last 6 months if treated with Rituximab

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm A; Arthritis or bursitis occurring in the context of a rare MIS or drug-induced toxicity."	Procedure: Biopsy; "A synovial biopsy will be carried out as recommended
Other: Arthritis or bursitis	Procedure: Biopsy; "A synovial biopsy will be carried out as recommended

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
characterize the inflammatory infiltrate in synovial biopsies	Establishment of a biobank to characterize the inflammatory infiltrate in synovial biopsies from arthritis or bursitis occurring in the context of rare systemic autoimmune diseases (SAIDs) or immune-mediated drug toxicities, and to compare it with the infiltrate in the synovium of arthritis/bursitis associated with common inflammatory rheumatic conditions frequently encountered in rheumatology.	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Study of the cytokine environment	Study of the cytokine environment within synovial biopsies from arthritis/bursitis occurring in the context of rare autoimmune/inflammatory syndromes or drug toxicity	day 1
Study of the cytokine environment	Study of the cytokine environment within synovial biopsies fromarthritis/bursitis arising in common inflammatory rheumatic diseases.	day 1
comparison of the cytokine environment	comparison cytokine environment within synovial biopsies from arthritis/bursitis occurring in the context of rare autoimmune/inflammatory syndromes or drug toxicity, n with that of arthritis/bursitis arising in common inflammatory rheumatic diseases.	day 1
Study of the gene expression profile of immune cells	Study of the gene expression profile of immune cells present within synovial biopsies from arthritis/bursitis occurring in the context of rare autoimmune/inflammatory syndromes or drug toxicity,	day 1
Study of the gene expression profile of immune cells	Study of the gene expression profile of immune cells present that of arthritis/bursitis occurring in common inflammatory rheumatic diseases."	day 1
comparison of the gene expression profile of immune cells	comparison of the gene expression profile of immune cells in synovial biopsies from arthritis/bursitis occurring in the context of rare autoimmune/inflammatory syndromes or drug toxicity versus those from arthritis/bursitis occurring in common inflammatory rheumatic diseases	day 1

Collaborators and Investigators

• Sponsor: University Hospital, Brest
• Collaborators: University Hospital, Bordeaux

Study record dates

Study Major Dates

• Study Start (Actual): March 27, 2026
• Primary Completion (Estimated): March 3, 2031
• Study Completion (Estimated): March 3, 2031

Study Registration Dates

• First Submitted: November 28, 2025
• First Submitted That Met QC Criteria: December 11, 2025
• First Posted (Actual): December 24, 2025

Study Record Updates

• Last Update Posted (Actual): April 3, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: connective tissue disease; Inflammatory arthritis; rare auto-immune diseases; immune checkpoint inhibitor related inflamamtory arthritis
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Skin and Connective Tissue Diseases; Arthritis; Connective Tissue Diseases; Investigative Techniques; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Surgical Procedures, Operative; Cytological Techniques; Cytodiagnosis; Diagnostic Techniques, Surgical; Biopsy
• Other Study ID Numbers: 29BRC24.037

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No