The "Intermediate" CD14⁺⁺CD16⁺ monocyte subset increases in severe peripheral artery disease in humans

Area of Science:

• Immunology
• Vascular Biology
• Atherosclerosis Research

Background:

• Monocytes are crucial in atherosclerosis, exhibiting heterogeneity with at least three subsets.
• While monocyte subset roles in coronary artery disease (CAD) are known, their significance in peripheral artery occlusive disease (PAOD) remains under-explored.

Purpose of the Study:

• To investigate monocyte subset heterogeneity and surface marker expression in patients with varying stages of PAOD.
• To identify potential diagnostic biomarkers and therapeutic targets for PAOD-associated inflammation.

Main Methods:

• Flow cytometry was used to identify and quantify three monocyte subsets (classical, non-classical, intermediate) in 143 PAOD patients.
• Expression levels of surface markers CD106, CD162, and myeloperoxidase (MPO) were analyzed on monocyte subsets.

Main Results:

• Proportions of CD14++CD16+ intermediate monocytes were significantly elevated in advanced PAOD stages (Rutherford stage I-VI).
• CD162 and MPO expression increased significantly on intermediate monocytes in advanced PAOD.
• Elevated CD162 and MPO expression was also observed on CD14++CD16- classical monocytes in advanced disease.

Conclusions:

• PAOD progression is associated with significant shifts in monocyte subset distribution and phenotype.
• These dynamic changes in monocyte subsets and marker expression may serve as valuable biomarkers for PAOD.
• Targeting these altered monocyte populations could offer novel therapeutic strategies to mitigate inflammation in advanced atherosclerosis.