Plain language summary
Peripheral artery disease (PAD) is one of the most advanced forms of atherosclerosis. This disease state begins from an inflammatory lesion. The aim of this study was to investigate the impact of a short-course, oral, enriched marine oil supplement on circulating leukocytes and biochemical mediators in patients with symptomatic PAD and healthy controls. This study is a prospective, open-label, nonblinded study. Twenty participants completed the study: ten with PAD and 10 healthy individuals. Results show: - a shift in the leukocyte profiling towards a less inflammatory and more pro-resolving phenotype, most notably within the PAD cohort. - that supplementation led to an increase in phagocytic [a type of immune cell] activity of peripheral blood monocytes and neutrophils. - that circulating monocyte phenotyping demonstrated reduced expression of multiple proinflammatory markers. - that gene expression patterns in mono-derived macrophage from patients with PAD displayed a less inflammatory (type 1 macrophage) and greater reparative (type 2 macrophage) phenotype after supplementation. Authors conclude that their findings provide a foundation for characterising biochemical and cellular biomarkers of inflammation and resolution in PAD.
Background Peripheral artery disease (PAD) is an advanced form of atherosclerosis characterized by chronic inflammation. Resolution of inflammation is a highly coordinated process driven by specialized pro-resolving lipid mediators endogenously derived from omega-3 fatty acids. We investigated the impact of a short-course, oral, enriched marine oil supplement on leukocyte phenotype and biochemical mediators in patients with symptomatic PAD and healthy volunteers. Methods and Results This was a prospective, open-label study of 5-day oral administration of an enriched marine oil supplement, assessing 3 escalating doses in 10 healthy volunteers and 10 patients with PAD. Over the course of the study, there was a significant increase in the plasma level of several lipid mediator families, total specialized pro-resolving lipid mediators, and specialized pro-resolving lipid mediator:prostaglandin ratio. Supplementation was associated with an increase in phagocytic activity of peripheral blood monocytes and neutrophils. Circulating monocyte phenotyping demonstrated reduced expression of multiple proinflammatory markers (cluster of differentiation 18, 163, 54, and 36, and chemokine receptor 2). Similarly, transcriptional profiling of monocyte-derived macrophages displayed polarization toward a reparative phenotype postsupplementation. The most notable cellular and biochemical changes over the study occurred in patients with PAD. There were strong correlations between integrated biochemical measures of lipid mediators (specialized pro-resolving lipid mediators:prostaglandin ratio) and phenotypic changes in circulating leukocytes in both healthy individuals and patients with PAD. Conclusions These data suggest that short-term enriched marine oil supplementation dramatically remodels downstream lipid mediator pathways and induces a less inflammatory and more pro-resolution phenotype in circulating leukocytes and monocyte-derived macrophages. Further studies are required to determine the potential clinical relevance of these findings in patients with PAD. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02719665.