Blood total cholesterol levels have long been known to be related to coronary heart disease (CHD). Total Cholesterol count is composed of LDL, HDL, along with triglycerides and Lp(a) cholesterol.
HDL (High Density Lipoprotein) EZ LDLTM Homogeneous Method
High Density Lipoprotein Cholesterol (HDL-C) has become an important tool used to assess an individual’s risk of developing CHD since a strong negative relationship between HDL-C concentration and the incidence of CHD has been reported. Most clinical laboratories routinely perform HDL-C analysis. The Trinity Biotech EZ HDL Cholesterol test employs the use of a specific antibody, and thus, can be applied on automated analysers.
METHOD Colormetric, immunological procedure for automated analysers.
PRINCIPLE Anti-human ß-lipoprotien antibody binds to lipoproteins (LDL, VLDL and chylomicrons) other than HDL cholesterol (HDL-C). The antigenantibody complexes formed block enzyme reactions when the enzymatic cholesterol reagent is added. Cholesterol esterase and cholesterol oxidase react only with HDL-C. Hydrogen peroxide produced by the enzyme reactions with HDL-C yields a blue colour complex upon oxidase consideration with FDAOS (N-ethyl-N-2hydroxy-3-sulfopropyl)-3, 5-dimethoxy, 4-Fluoroanaline sodium salt and 4-aminoantipyrine in the presence of peroxidase.
By measuring the absorbance of the blue colour complex produced at approximately 600 nm, the HDL-C concentrationin the sample can be calculated when compared when the absorbance on the calibrator.
DIAGNOSTIC IMPLICATIONS About one-fourth to one-third of blood cholesterol is carried by high-density lipoprotein (HDL). HDL cholesterol is known as ‘good’ cholesterol, because high levels of HDL seem to protect against heart attack. Low levels of HDL (less than 40 mg/dL) also increase the risk of heart disease. Medical experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it is passed from the body. Some experts believe that HDL removes excess cholesterol from arterial plaque, thus slowing its build up.