Screening test for determination of multiple-modified lipoproteins of low density — marker of subclinical atherosclerosis

Abstract

A screening test was developed to determine multiply-modified low-density lipoprotein (mmLDL) in serum for routine studies. Incubation of serum in a buffer containing 9.1% polyvinylpyrrolidone 35,000 (PVP-35) results in complete aggregation of mmLDL. Pathogenicity of isolated mmLDL was confirmed during binding tests of the complement system and lytic activity in vitro, and also in vascular dystonia test with rats in vivo. The proposed method is characterized by high productivity, low cost, includes 2 operations — mixing serum with a solution of 10% PVP-35 in 96-well immunoassay plates, incubating for 10 min at room temperature and turbidimetry at 450 nm on an ELISA reader. A study was made to determine relationship between concentration of mmLDL in the blood serum and thickness of the intima-media complex from data of ultrasound duplex scanning of carotid arteries with 78 people with low cardiovascular risk (SCORE <1%) and low cardiovascular risk (CMDS 0-1). Of all fractions of the lipid spectrum of the blood, mmLDL showed the highest correlation coefficient with the indices of subclinical atherosclerosis, which confirms high atherogenic potential of mmLDL.