HDL CHOLESTROL

CLINICAL SIGNIFICANCE

The principal role of high density lipoproteins (HDL) in lipid metabolism
is the uptake and transport of cholesterol from peripherical tissues to
the liver through a process known as reverse cholesterol transport.
Low HDL cholesterol levels are strongly associated with an increased
risk of coronary heart disease and coronary artery disease. Hence, the
determination of serum HDL-Cholesterol is a useful tool in identifying
high-risk patients. Increased Total Cholesterol/HDL-Cholesterol ratio is
significant of an increased risk of atherosclerosis.
PRINCIPLE
Accelerator selective detergent methodology.
Direct method, without specimen pre-treatment.
During the first phase, LDL, VLDL particles and Chylomicrons
generate free Cholesterol, which through an enzymatic reaction,
produce Hydrogen peroxide. The generated peroxide is consumed by
a peroxidase reaction with DSBmT yielding a colourless product.
During
the
second
phase,
specific
detergent
solubilises
HDL-Cholesterol. In conjunction with CO and CE action, POD + 4-AAP
develop a coloured reaction which is proportional to HDL-Cholesterol
concentration. The absorbance is measured at 600 nm.
LDL =
Low density lipoproteins
HDL =
High density lipoproteins
VLDL = Very low density lipoproteins
POD =
Peroxidase
CO =
Cholesterol Oxidase
CE =
Cholesterol Esterase
4-AAP = 4-Aminoantipyrine
AAO =
Ascorbate OxIdase
DSBmT = N,N-bis (4-sulphobutyl)-m-toluidine-disodium