Calciprotein particle (CPP) (CPP)

Calciprotein particles (CPPs) are colloidal nanoparticles that form in the blood as a physiological mechanism to prevent the precipitation of calcium and phosphate [Heiss et al., 2003]. They are composed of a mineral core (calcium phosphate) stabilized by serum proteins, primarily Fetuin-A. CPPs progress from a small, amorphous primary state (CPP1) to a larger, crystalline secondary state (CPP2), which is highly bioactive and pro-inflammatory [Koeppert et al., 2018]. In patients with chronic kidney disease, the failure to clear these particles leads to their deposition in the vasculature, where they act as a nidus for ectopic calcification [Pasch et al., 2012]. Therapeutic interventions, such as SNF472, aim to stabilize CPPs in their primary form or inhibit the growth of hydroxyapatite crystals to reduce cardiovascular risk [Brandenburg et al., 2019]. Monitoring CPP maturation via the T50 test provides a critical biomarker for assessing calcification risk and treatment efficacy in clinical settings.

Other names

CPP1CPP2Fetuin-A-containing calciprotein particlesMineral-protein complexesNanocalcification nidusEarly calcification nidus

Inhibition of hydroxyapatite crystal growth and stabilization of amorphous calcium phosphate to prevent the transition from primary to secondary calciprotein particles [Brandenburg et al., 2019].