ApoB100containing

ApoB-100-containing lipoproteins refer to a subset of plasma lipoproteins that carry apolipoprotein B-100 (ApoB-100) as their primary structural protein. They are produced in the liver and include very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL). Each particle typically contains a single ApoB-100 molecule, which acts as the essential scaffold and ligand for receptor binding.

Metabolism and function: ApoB-100 is required for the assembly and stability of these particles. VLDL is secreted by the liver and delivers triglycerides to peripheral tissues; through lipolysis and remodeling, VLDL is converted to IDL and then LDL. LDL particles deliver cholesterol to cells via LDL receptors, a process that regulates cellular cholesterol homeostasis. Chylomicrons, in contrast, carry ApoB-48, not ApoB-100, while high-density lipoprotein (HDL) generally lacks ApoB-100.

Clinical significance: Circulating ApoB-100-containing lipoproteins are central to atherosclerotic risk because their number often reflects the total load of atherogenic particles. Elevated levels are associated with increased risk of cardiovascular disease. Some guidelines consider apoB-100 or apoB (the protein itself) a useful marker of risk, sometimes preferred over LDL cholesterol in certain clinical contexts. Genetic variants in the APOB gene can affect ApoB-100 function, including conditions such as familial defective ApoB-100, which can impair receptor binding and clearance.

Measurement: ApoB-100 can be measured by immunoassays, while non-HDL cholesterol serves as a broader surrogate for all ApoB-100–containing, atherogenic lipoproteins.