Disease Activity Monitoring in Patients With Giant Cell Arteritis Study (DiAcMo)

Disease Activity Monitoring in Patients With Giant Cell Arteritis

Giant Cell Arteritis (GCA) is a vasculitis of medium- and large-sized arteries in older adults that may lead to serious vascular complications, including permanent vision loss and aortic aneurysm formation. Glucocorticoids are effective, but relapse during tapering is common and poses a major clinical challenge, potentially contributing to prolonged glucocorticoid exposure. Symptoms are often nonspecific and conventional inflammatory markers lack sufficient reliability, particularly in patients treated with drugs targeting the interleukin-6 pathway. Thus, this project aims to evaluate different tools assisting disease activity monitoring and/or predict future relapses and higher treatment requirements. Up to 175 patients with GCA in remission will be enrolled to ensure that 144 participants complete 1 year of follow-up. Participants undergo vascular ultrasonography, including double-blinded assessment at suspected relapse, complete patient-reported outcome measures, and provide biobank blood samples.

Study Overview

• Status: Recruiting
• Conditions: Giant Cell Arteritis (GCA)

• Study Type: Observational
• Enrollment (Estimated): 175

Contacts and Locations

• Study Contact: Name: Morten Hansen, Medical Doctor; Phone Number: +45 20187463; Email: mothas@rm.dk

Study Locations

• Denmark
  • Aalborg, Denmark, 9000
    • Not yet recruiting
    • Aalborg University Hospital, Department of Rheumatology
    • Contact: Salome Kristensen, MD, PhD; Phone Number: +45 97664015; Email: sakr@rn.dk
  • Aarhus, Denmark, 8200
    • Not yet recruiting
    • Aarhus University Hospital, Department of Rheumatology
    • Contact: Ellen Margrethe Hauge, MD, PhD; Phone Number: +45 2478 6025; Email: ellen.hauge@aarhus.rm.dk
  • Glostrup Municipality, Denmark, 2600
    • Not yet recruiting
    • Rigshospitalet Glostrup, Center for Rheumatology and Spine Diseases Rigshospitalet
    • Contact: Lene Terslev, MD, PhD, DMSc; Phone Number: +45 35454131; Email: terslev@dadlnet.dk
  • Horsens, Denmark, 8700
    • Recruiting
    • Regional Hospital Horsens, Department of Medicine
    • Contact: Berit Dalsgaard Nielsen, MD, PhD; Email: beritnel@rm.dk
  • Silkeborg, Denmark, 8600
    • Not yet recruiting
    • Hospitalsenhed Midt, Medicinsk Diagnostisk Center
    • Contact: Søren Geill Kjær, MD; Phone Number: +45 6171 7078; Email: soekjaer@rm.dk
  • Svendborg, Denmark, 5700
    • Not yet recruiting
    • Svendborg Hospital, Department of Medicine
    • Contact: Bill Aplin Frederiksen, MD; Phone Number: +45 6320 2246; Email: Bill.Aplin.Frederiksen@rsyd.dk
  • Vejle, Denmark, 7100
    • Not yet recruiting
    • Vejle Hospital, Department of Medicine
    • Contact: Stavros Chrysidis, MD, PhD; Phone Number: +45 79409635; Email: Stavros.Chrysidis@rsyd.dk

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Patients with giant cell arteritis (ICD-10: M31.5, M31.6) in clinical remission but still undergoing glucocorticoid tapering or tapering of glucocorticoid-sparing treatment.

Description

Inclusion Criteria:

1. Clinical GCA diagnosis established/confirmed by a rheumatologist and positive GCA imaging or biopsy at diagnosis < 3 years.

2. Clinical remission at the time of inclusion, defined as

   • Having adhered for ≥ 8 weeks prior to inclusion to either (a) the planned tapering of glucocorticoid therapy, or (b) the planned glucocorticoid-sparing DMARD treatment (with or without glucocorticoids).
   • Absence of, or no worsening of, symptoms attributed to GCA in ≥ 8 weeks.
   • Normal CRP level (< 10 mg/L) within 7 days before inclusion.
3. Current prednisolone dosage of ≥ 5 mg if glucocorticoid monotherapy.
4. A continuous tapering of monotherapy or combination therapy is planned.
5. Age > 50 years.
6. Study participants must be able to speak and understand spoken and written Danish.

Exclusion Criteria:

1. Intra-articular, intravenous or intramuscular glucocorticoid ≤ 7 weeks prior to inclusion.
2. Study participants who are unable to complete online questionnaires cannot participate in the GCA-PRO component of the study.
3. Presence of cognitive impairment, including clinically significant dementia, that may interfere with the ability to provide informed consent or comply with study procedures.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sensitivity and specificity of change in OGUS from inclusion to suspected relapse	Sensitivity and specificity of change in OMERACT Ultrasonography GCA Score (OGUS) from inclusion to suspected relapse (Follow-up 1a) for relapse/non-relapse using the reassessment at Follow-up 2 as the reference standard.	Within 10 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of correctly classified relapse/non-relapse by vascular ultrasonography among participants with clinically uncertain relapse	Proportion of correctly classified relapse/non-relapse by vascular ultrasonography among participants with clinically uncertain relapse (Follow-up 1a) using the reassessment at Follow-up 2 as the reference standard. Key secondary.	Within 10 months
Predictive cut-off values of vascular ultrasonography scores at remission for relapse	The predictive cut-off values of vascular ultrasonography scores (OGUS and halo count) at remission (inclusion) for relapse within 12 months of inclusion using Follow-up 2 as the reference standard. Key secondary.	12 months
Sensitivity and specificity of change in halo count from inclusion to suspected relapse	The sensitivity and specificity of change in halo count from remission (inclusion) to Follow-up 1a for relapse/non-relapse using the reassessment at Follow-up 2 as the reference standard.	Within 10 months
Sensitivity and specificity of vascular ultrasonography scores at suspected relapse	The sensitivity and specificity of US scores (OMERACT Ultrasonography GCA Score and halo count) at suspected relapse (Follow-up 1) for relapse/non-relapse using the reassessment at Follow-up 2 as the reference standard.	Within 10 months
Sensitivity and specificity of vascular ultrasonography scores for relapse/non-relapse in subgroups defined by OMERACT ultrasonography morphology	The sensitivity and specificity of vascular ultrasonography scores for relapse/non-relapse in subgroups defined by OMERACT US morphology (normal, active vasculitis, chronic vasculitis, atherosclerotic) using the reassessment at Follow-up 2 as the reference standard.	Within 10 months
Change in probability of relapse and non-relapse before and after vascular ultrasonography	Change in probability of relapse and non-relapse before and after vascular ultrasonography using clinician-rated pre-test probability and ultrasonography likelihood ratios.	Within 10 months
Time from suspected relapse to clinical conclusion in participants with clinically uncertain relapse that were correctly classified with vascular ultrasonography	The time (potentially saved) from suspected relapse (Follow-up 1a) to clinical conclusion (relapse review) in participants with clinically uncertain relapse that were correctly classified with vascular ultrasonography compared to the reference standard (Follow-up 2).	12 months
Number of supplementary tests ordered at suspected relapse to clinical conclusion in participants with clinically uncertain relapses/non-relapse that were correctly classified by vascular ultrasonography	The number of supplementary tests ordered at suspected relapse (Follow-up 1a) to clinical conclusion (relapse review) in participants with clinically uncertain relapses/non-relapse that were correctly classified by vascular ultrasonography using the reassessment at Follow-up 2 as the reference standard.	12 months
Time to relapse over 12 months in relation to vascular ultrasonography scores at inclusion	Time to relapse over 12 months evaluated in relation to vascular ultrasonography scores at inclusion (remission).	12 months
Change in GCA-PRO scores from remission to relapse	Change in Giant Cell Arteritis Patient Reported Outcome Measure (GCA-PRO) scores from remission (inclusion) to relapse (Follow-up 1a) using the reassessment at Follow-up 2 as reference standard. The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on health-related quality of life (HRQoL) and 90 indicates high disease impact (poor HRQoL). Key secondary.	Within 10 months
Change in GCA-PRO scores at relapse and 10 days after treatment escalation.	Change in GCA-PRO scores at relapse and 10 days after treatment escalation. The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on HRQoL and 90 indicates high disease impact (poor HRQoL).	Within 10 months
Convergence of GCA-PRO scores with other surrogate markers of disease activity from remission to relapse	Convergence of GCA-PRO scores with, respectively, c-reactive protein levels, patient and physician global activity numeric rating scale scores, and vascular ultrasonography scores (halo count and OGUS) from remission (inclusion) to relapse (Follow-up 1a). The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on HRQoL and 90 indicates high disease impact (poor HRQoL).	Within 10 months
Sensitivity and specificity of change in GCA-PRO scores from inclusion to suspected relapse	The sensitivity and specificity of change in GCA-PRO scores from inclusion to suspected relapse (Follow-up 1a) for relapse/non-relapse using the reassessment at Follow-up 2 as the reference standard. The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on HRQoL and 90 indicates high disease impact (poor HRQoL).	Within 10 months
Sensitivity and specificity of GCA-PRO scores at suspected relapse	The sensitivity and specificity of GCA-PRO scores at suspected relapse (Follow-up 1a) for relapse/non-relapse using the reassessment at Follow-up 2 as the reference standard. The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on HRQoL and 90 indicates high disease impact (poor HRQoL).	Within 10 months
Relapse within 12 months evaluated in relation to GCA-PRO scores at inclusion.	Relapse within 12 months evaluated in relation to GCA-PRO scores at inclusion. The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on HRQoL and 90 indicates high disease impact (poor HRQoL).	12 months
Time to relapse over 12 months evaluated in relation to GCA-PRO scores at inclusion.	Time to relapse over 12 months evaluated in relation to GCA-PRO scores at inclusion. The total score for the GCA-PRO ranges from 0 to 90, where 0 indicates no impact on HRQoL and 90 indicates high disease impact (poor HRQoL).	12 months

Collaborators and Investigators

• Sponsor: University of Aarhus
• Collaborators: Aarhus University Hospital; Glostrup University Hospital, Copenhagen; Vejle Hospital; Aalborg University Hospital; Svendborg Hospital; Horsens Hospital; Regionshospitalet Silkeborg

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2026
• Primary Completion (Estimated): March 1, 2028
• Study Completion (Estimated): February 1, 2029

Study Registration Dates

• First Submitted: April 20, 2026
• First Submitted That Met QC Criteria: April 20, 2026
• First Posted (Actual): April 27, 2026

Study Record Updates

• Last Update Posted (Actual): May 29, 2026
• Last Update Submitted That Met QC Criteria: May 27, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: giant cell arteritis; patient-reported outcome measures; vascular ultrasonography; disease activity monitoring
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Autoimmune Diseases; Immune System Diseases; Autoimmune Diseases of the Nervous System; Skin Diseases; Skin Diseases, Vascular; Vasculitis; Vasculitis, Central Nervous System; Arteritis; Skin and Connective Tissue Diseases; Giant Cell Arteritis
• Other Study ID Numbers: DiAcMo; 10.46540/5333-00156B (Other Grant/Funding Number: Independent Research Fund Denmark)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All IPD that underlie results in the publications.
• IPD Sharing Time Frame: After completion of the study.
• IPD Sharing Access Criteria: By reasonably request.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

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