Quantification of the initial levels of calciprotein particles as a screening marker of mineral homeostasis in patients with cardiovascular disease and in patients with chronic kidney disease

Abstract

Aim. To evaluate the initial concentration of calciprotein particles (CPPs), which are scavengers of excessive calcium and phosphate, in patients with cardiovascular disease and in patients with chronic kidney disease as compared with the healthy volunteers.Material and methods. The study included 308 individuals as follows: 1) 88 participants of the PURE study without hemodynamically relevant carotid athero scle rosis and symptomatic coronary atherosclerosis; 2) 88 patients with cere brovascular disease (CVD) who required carotid endarterectomy; 3) 88 pa tients with coronary artery disease (CAD) who required percutaneous coronary intervention or coronary artery bypass graft surgery; 4) 63 patients with stage 5 chronic kidney disease (CKD). We measured following mineral homeostasis parameters: total and ionized calcium, phosphate, total protein, albumin, and fetuin-A. Then, we determined a baseline serum CPP concentration by flow cytometry using a fluorescent-labeled bisphosphonate OsteoSense 680EX. Results. In comparison with other patients, healthy volunteers had the highest serum CPP concentration (249 CPPs/µL), indicating the retained ability to compensate mineral homeostasis disturbances by aggregation of excessive calcium and pho sphate with acidic proteins (mineral chaperones). Reduced serum CPP concentration in patients with CVD (170 CPPs/µL), CAD (139 CPPs/µL), and stage 5 CKD (193-203 CPPs/µL) showed impaired aggregation of excessive serum calcium and phosphate, which was also reflected by an increased level of blood ionized calcium.Conclusion. Patients with CVD, CAD, and stage 5 CKD have lower serum CPP concentration than healthy individuals. In combination with elevated ionized calcium and reduced albumin, this suggests the depletion of calcium binding buffers in the serum of patients with cardiovascular and renal diseases.