Test Background Apo A1 constitutes the major component of high density lipoprotein (HDL). Apo A1 is an activator of the enzyme lecithin:cholesterol acyltransferase and removes free cholesterol from extrahepatic tissues. Apo A1 concentrations correlate with high density lipoprotein cholesterol and thus low levels are a risk factor for coronary artery disease. Rarely, very low levels are seen in hereditary deficiency of LPA1.
Clinical Indications Patients with a personal or family history of high concentrations of lipids and/or premature coronary heart disease
Determine cause of high lipid concentrations with suspicion of a deficiency
Used with Apo B to check ratio for coronary heart disease risk
To monitor effectiveness of changes to lipid-lowering treatment or lifestyle changes
Reference Range Male: 0.96-1.76 g/L
Female: 1.09-2.03 g/L