OxPL on Lp(a) Elicits Arterial Wall Inflammation and Monocyte Trafficking via LOX-1

This translational study combined mechanistic in vitro experiments with in vivo imaging in 60 patients with elevated versus normal Lp(a) to characterize how oxidized phospholipids (OxPL) on Lp(a) elicit arterial wall inflammation and inflammatory monocyte trafficking — specifically through the LOX-1 (lectin-like oxidized LDL receptor-1) pathway.

Lp(a)-OxPL activated LOX-1 on monocytes, inducing an inflammatory monocyte phenotype characterized by upregulation of pro-inflammatory cytokines and adhesion molecules. In the in vivo component, patients with high Lp(a) showed greater arterial wall FDG uptake by PET/CT (reflecting active vascular inflammation) than patients with normal Lp(a), even after adjusting for LDL-C and other risk factors. The circulating monocyte inflammatory phenotype correlated with arterial wall FDG uptake.

This study mechanistically links three elements: (1) OxPL as Lp(a)‘s pathogenic cargo, (2) LOX-1 as the receptor that transduces OxPL’s inflammatory signal in circulating monocytes, and (3) the resulting arterial wall inflammatory activation detectable by PET imaging. Together, these establish a complete mechanistic chain from Lp(a) particle biology to in vivo arterial inflammation in humans.

The study’s translational design — combining cell biology, animal data, and human imaging in a single paper — represents an unusually complete mechanistic characterization. The LOX-1 pathway is a potential therapeutic target for limiting Lp(a)‘s inflammatory effects independent of particle count reduction.

We rate the evidence strong. A mechanistically rigorous translational study in 60 patients demonstrating that OxPL on Lp(a) drives arterial wall inflammation and inflammatory monocyte activation via LOX-1 — providing the most complete in-human mechanistic evidence for Lp(a)‘s direct atherogenic role as an inflammatory mediator.