An observational study in Giant Cell Arteritis (GCA), sponsored by University of Aarhus. Recruiting at 7 sites in Denmark. Open to participants aged 50 Years and older. Per ClinicalTrials.gov, last updated 2026-08-31.
Sponsored by University of Aarhus · Observational
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.
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.
Clinical remission at the time of inclusion, defined as
Exclusion Criteria:
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.
Time frame: Within 10 months
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.
Time frame: 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.
Time frame: 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.
Time frame: Within 10 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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).
Time frame: 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.
Time frame: 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).
Time frame: 12 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).
Time frame: 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).
Time frame: 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).
Time frame: 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).
Time frame: 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).
Time frame: 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).
Time frame: 12 months
Plan to share: Yes — All IPD that underlie results in the publications.
Supporting information: Study protocol, Sap, Icf
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University of Aarhus