Remnant lipoprotein particles (RLP) (RLP)

Remnant lipoprotein particles (RLPs) are the partially catabolized products of triglyceride-rich lipoproteins, specifically chylomicrons and very-low-density lipoproteins (VLDL) (NIH: Lipoprotein Metabolism). These particles are formed through the action of lipoprotein lipase (LPL), which removes triglycerides, leaving behind particles enriched in cholesterol esters and Apolipoprotein E (StatPearls: Hyperlipoproteinemia Type III). In Hyperlipoproteinemia Type I (Familial Chylomicronemia Syndrome), a deficiency in LPL or its cofactor ApoC-II prevents the initial breakdown of chylomicrons, leading to severe hypertriglyceridemia and a high risk of acute pancreatitis (StatPearls: Hyperlipoproteinemia Type I). In Hyperlipoproteinemia Type III (Dysbetalipoproteinemia), defective Apolipoprotein E variants impair the hepatic recognition and clearance of these remnants, causing their accumulation in the plasma (Journal of Clinical Lipidology: Remnant Cholesterol). These remnants are highly pro-atherogenic as they can penetrate the arterial wall and are readily taken up by macrophages to form foam cells, contributing to premature cardiovascular disease. Pharmacological intervention focuses on reducing RLP levels by enhancing LPL activity, inhibiting LPL inhibitors such as Apolipoprotein C-III or ANGPTL3, or increasing hepatic receptor-mediated clearance (Nature Reviews Cardiology: Lipoprotein Remnants).

Other names

Chylomicron remnantsVLDL remnantsIntermediate-density lipoproteinsIDLBeta-VLDLRemnant-like particlesBroad-beta lipoproteins

Therapeutic agents reduce remnant particles by several mechanisms: fibrates activate PPAR-alpha to increase lipoprotein lipase (LPL) expression; antisense oligonucleotides like volanesorsen and olezarsen inhibit Apolipoprotein C-III (an LPL inhibitor); monoclonal antibodies like evinacumab inhibit ANGPTL3 (another LPL inhibitor); and statins or PCSK9 inhibitors upregulate LDL receptors to facilitate the hepatic uptake of VLDL remnants (StatPearls: Hyperlipidemia; Nature Reviews Cardiology).