Macrophage component of atherosclerotic plaque

The macrophage component of atherosclerotic plaque refers to the collection of immune cells that infiltrate the arterial wall and orchestrate the inflammatory response in atherosclerosis (Libby, 2021). These cells are primarily derived from circulating monocytes that differentiate into macrophages and, upon ingesting oxidized low-density lipoproteins, become lipid-laden foam cells (Moore et al., 2013). Macrophages within the plaque contribute to disease progression by secreting pro-inflammatory cytokines, such as interleukin-1 beta (IL-1β), and matrix metalloproteinases that degrade the plaque's structural integrity (Ridker et al., 2017). This cellular component is a critical focal point for therapeutic intervention, as reducing macrophage-driven inflammation has been shown to lower the risk of major adverse cardiovascular events. Additionally, these cells serve as a target for diagnostic imaging, where tracers like 18F-fluorodeoxyglucose (FDG) are used to visualize high metabolic activity as a proxy for plaque vulnerability (Tarkin et al., 2014). Although not a single protein or receptor, the macrophage population provides a biological context for numerous specific molecular targets, including scavenger receptors and inflammasome components. Current pharmacological approaches include the use of statins to reduce lipid accumulation and monoclonal antibodies to neutralize macrophage-derived cytokines.

Other names

Atherosclerotic plaque macrophagesIntraplaque macrophagesFoam cellsPlaque-associated macrophages

Drugs targeting this component typically aim to reduce inflammatory signaling (e.g., IL-1β inhibition), promote cholesterol efflux, or stabilize the plaque by reducing the secretion of matrix-degrading enzymes. Imaging agents exploit the high metabolic activity or phagocytic nature of these cells for lesion visualization.