Randox Unveils an Assay for the Rapid Measurement of Small Dense LDL Cholesterol (sdLDL-C)

A kit for the automated measurement of small dense low-density lipoprotein cholesterol (sdLDL-C) is now available with dedicated controls and calibrators available and instrument-specific applications for use with a wide range of biochemistry analyzers.

The lipid panel often used to assess cardiovascular disease risk comprises LDL cholesterol, HDL cholesterol, total cholesterol, and triglycerides. Results of these assays only detect about 20% of all atherosclerotic cardiovascular disease patients. However, studies have shown that sdLDL-C could predict risk of coronary heart disease in individuals considered being at low cardiovascular risk based on their LDL-C levels. These studies found that patients with a predominance of sdLDL-C had a three-fold increased risk of myocardial infarction (MI), while the relative risk was 4.5 for coronary artery disease and 7.0 for MI when sdLDL-C levels were greater than 100 milligrams per deciliter.


Until recently, the primary methods for determining a patient's sdLDL-C levels were based on laborious and time-consuming ultracentrifugation and electrophoresis. Then, in November 2017, the [U.S.] Food and Drug Administration granted 510(k) marketing clearance to Denka Seiken (Tokyo, Japan) for a small dense low-density lipoprotein cholesterol (sdLDL-C) assay designed for use on any standard clinical chemistry analyzer. The assay quantified sdLDL-C in serum and plasma samples in 10 minutes using a two-step process. The first step removed chylomicrons, very low LDL, intermediate-density lipoprotein, large LDL, and high-density lipoprotein using a surfactant and sphingomyelinase. In the second step, a specific surfactant released cholesterol only from the sdLDL-C particles for measurement by standard methods.

The Randox (Crumlin, United Kingdom) sdLDL-C assay utilizes the Denka Seiken method, providing accurate patient results. It was designed for use on automated biochemistry analyzers for efficiency and convenience. Applications are available detailing instrument-specific settings for the convenient use of the Randox sdLDL-C assay on a wide range of biochemistry analyzers. Dedicated sdLDL-C controls and calibrator are available providing a complete testing package. The Randox sdLDL-C assay is a niche product, and Randox is one of the only manufacturers of this test in an automated format.