Expression of GLP1 Receptor on Peripheral Blood Mononuclear Cells in Advanced Peripheral Artery Disease: Paving the Way for GLP1R Agonists Treatment in Chronic Limb Threatening Ischemia

Chronic limb-threatening ischemia is the most severe stage of lower-limb peripheral arterial disease and remains associated with poor cardiovascular and limb prognosis. This condition is characterized by a pronounced systemic inflammatory and oxidative state, in which peripheral blood mononuclear cells play a central role.

Glucagon-like peptide-1 receptor agonists have shown anti-inflammatory and cardiovascular protective effects in other settings, but the involvement of the GLP-1 receptor in severe peripheral arterial disease has not been clearly established. This pilot study aims to characterize GLP-1 receptor expression on peripheral blood mononuclear cells according to disease severity and to evaluate its association with inflammatory, oxidative, and proteomic profiles.

This is a monocentric, cross-sectional observational study conducted at the CHU of Strasbourg. Patients hospitalized for evaluation of symptomatic lower-limb peripheral arterial disease will be classified into intermittent claudication or chronic limb-threatening ischemia groups. A single additional blood sample will be collected during routine clinical sampling. Peripheral blood mononuclear cells and plasma will be analyzed to assess GLP-1 receptor expression, inflammatory and oxidative markers, and plasma proteomic signatures. Exploratory in-vitro experiments will evaluate the ability of GLP-1 receptor agonists to reverse endothelial alterations induced by patient plasma.

The study is designed to generate mechanistic data supporting the GLP-1 receptor as a potential therapeutic target in chronic limb-threatening ischemia and to inform future interventional studies.

• Analysis of GLP-1 receptor expression (Diagnostic test): One-time 15mL blood sampling for GLP-1R expression analysis on PBMCs via RT-qPCR and Western blot

Primary outcomes

• Level of GLP-1 Receptor (GLP-1R) Gene Expression in PBMCs [Day 1 (at the time of the one-time blood sampling)]: Quantification of GLP-1R mRNA expression levels in Peripheral Blood Mononuclear Cells (PBMCs) using RT-qPCR. This measure aims to compare the level of receptor expression between patients with Intermittent Claudication and those with Chronic Limb-Threatening Ischemia.

Secondary outcomes

• Systemic Pro-inflammatory Cytokine Profile [Day 1]: Concentration of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) measured in pg/mL using ELISA
• Oxidative and Nitrosative Stress Markers in PBMCs [Day 1]: Measurement of Nitric Oxide (NO) and Reactive Oxygen Species (ROS) levels in PBMCs using fluorescent probes and flow cytometry (expressed as Mean Fluorescence Intensity).

Sex: All, ages: 40 Years to any

Inclusion Criteria:

* Patients aged 40 years or older
* Documented Peripheral Artery Disease (PAD): Patients must fall into one of the two following severity groups:

  1. Intermittent Claudication (IC) Group: Defined by a maximum walking distance limited by intermittent claudication, associated with an Ankle-Brachial Index (ABI) < 0.9 at rest.
  2. Chronic Limb-Threatening Ischemia (CLTI) Group: Defined by ischemic rest pain and/or tissue loss (ulcers or gangrene) persisting for at least 15 days, associated with a toe pressure or a transcutaneous oxygen tension (tcPO2) < 30 mmHg, according to the 2024 ESC guidelines.

Exclusion Criteria:

* Diabetes Mellitus: Diagnosis of Type 1 or Type 2 diabetes
* Current Specific Pharmacotherapy: Ongoing treatment with SGLT2 inhibitors (SGLT2i) or GLP-1 receptor agonists (GLP-1RA).
* Infection: Presence of sepsis or an active systemic infection.
* Malignancy: Active cancer or hematologic malignancies.
* Immunosuppression: History of organ transplantation or autoimmune diseases currently requiring immunosuppressive therapy.
* Known chronic inflammatory diseases.
* Advanced Renal Failure: End-stage renal disease requiring dialysis.