Chylomicrons: Advances in biology, pathology, laboratory testing, and therapeutics

The adequate absorption of lipids is essential for all mammalian species due to their inability to synthesize some essential fatty acids and fat-soluble vitamins. Chylomicrons (CMs) are large, triglyceride-rich lipoproteins that are produced in intestinal enterocytes in response to fat ingestion, which function to transport the ingested lipids to different tissues. In addition to the contribution of CMs to postprandial lipemia, their remnants, the degradation products following lipolysis by lipoprotein lipase, are linked to cardiovascular disease. In this review, we will focus on the structure–function and metabolism of CMs. Second, we will analyze the impact of gene defects reported to affect CM metabolism and, also, the role of CMs in other pathologies, such as atherothrombotic cardiovascular disease and diabetes mellitus. Third, we will provide an overview of the laboratory tests currently used to study CM disorders, and, finally, we will highlight current treatments in diseases affecting CMs. •Chylomicrons are large, triglyceride-rich lipoproteins formed in the intestine after a meal.•Fasting healthy people have no chylomicrons in the blood serum.•Most of monogenic diseases causing hyper- or hypochylomicronemia that can be diagnosed by clinical chemistry and genetic studies.•Hyperchylomicronemia is a major risk factor of pancreatitis•The first gene therapy approved in Europe is directed to LPL deficiency, the main cause of type I hyperlipidemia.