CXCR4-PET/CT for Diagnosing Giant Cell Arteritis

Sponsor

Matthias Fröhlich (Other)

Overall Status

Recruiting

CT.gov ID

NCT05604482

Collaborator

(none)

Enrollment

Location

Arm

Anticipated Duration (Months)

0.5

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Giant cell arteritis (GCA) is the most common vasculitis in the elderly. Accurate diagnosis is of utmost importance in order to then initiate the necessary immunosuppressive therapy. For large-vessel GCA (LV-GCA) involving the aorta and its branches, FDG-PET/CT is the standard in imaging for diagnosis and is recommended by the guidelines. However, this only indirectly visualizes inflammation through vessel wall uptake of glucose. A new PET tracer, 68Ga-pentixafor, is used to visualize the chemokine receptor CXCR4. This receptor is expressed by cells of the immune system. In the context of inflammatory processes, upregulation of CXCL12, the ligand of CXCR4, occurs in affected tissues. The chemotactic effect of this ligand leads to the immigration of CXCR4-positive inflammatory cells into the inflamed area, which can be visualized by PET using the CXCR4-specific tracer 68Ga-Pentixafor. The value of CXCR4-PET should therefore be tested in the context of LV-GCA. This study tests the benefit of CXCR4 in therapy-naïve patients with suspected LV-GCA. For this purpose, patients will receive a FDG-PET and a CXCR4-PET for direct comparison. This is an imaging-only study. Therapy will not be affected by the study. The study is single-arm and not blinded.

Condition or Disease	Intervention/Treatment	Phase
Vasculitis Diagnoses Disease	Diagnostic Test: CXCR4-PET	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

12 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Diagnostic

Official Title:

Detection of Disease Activity in Giant Cell Arteritis Using CXCR4-PET/CT

Actual Study Start Date :

Oct 1, 2021

Anticipated Primary Completion Date :

Sep 30, 2023

Anticipated Study Completion Date :

Sep 30, 2023

Arms and Interventions

Arm	Intervention/Treatment
Experimental: CXCR4-PET experimental group In addition to the current standard of imaging in GCA, using FDG-PET/CT, participants receive CXCR4-PET.	Diagnostic Test: CXCR4-PET New imaging modality using CXCR4 for imaging in GCA

Arm

Intervention/Treatment

Experimental: CXCR4-PET experimental group

In addition to the current standard of imaging in GCA, using FDG-PET/CT, participants receive CXCR4-PET.

Diagnostic Test: CXCR4-PET

New imaging modality using CXCR4 for imaging in GCA

Outcome Measures

Primary Outcome Measures

Maximum measurable tracer activity on 68Ga-Pentixafor PET/CT in the area of blood vessels in active GCA [2 years]
detection of maximum measurable tracer activity on 68Ga-Pentixafor PET/CT in the area of blood vessels after a maximum of 5 days after diagnosis or when acute inflammatory activity of GCA is detected in terms of recurrence.

Secondary Outcome Measures

Correlation with clinical parameters [2 years]
Correlation of the measured tracer activity with clinically and laboratory-chemically available parameters that are collected in clinical routine. These include CRP, peripheral blood leukocyte count, calprotectin, serum amyloid A, haptoglobin and Lactate dehydrogenase and their respective progression.
Correlation with blood leukocyte count [2 years]
Correlation of tracer uptake on imaging with CXCR4-positive peripheral blood leukocyte count.
Comparison to other imaging modalities [2 years]
Comparison with imaging findings from vasculitis MRI imaging implemented in standard clinical practice, duplex sonography (CCDS), and, if performed as part of routine clinical practice, FDG PET/CT data.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

New diagnosis of GCA within 5 days of diagnosis or initiation or intensification of therapy.
Evidence of inflammatory activity based on clinical parameters, elevated serologic markers of inflammation (CRP > 1.0 mg/dl), or a positive imaging finding on vasculitis MRI, CCDS, or FDG-PET/CT
Ability of the patient to provide information
Exclusion of contraindications for the performance of a PET/CT examination (see below)