Fetuin-A function in systemic mineral metabolism.

Fetuin-A is a liver-derived plasma protein involved in calcified matrix metabolism. Fetuin-A mediates the formation and stabilization of calciprotein particles (CPPs), soluble colloids made of fetuin-A, further serum proteins, and calcium phosphate mineral. CPP formation ensures mineral solubilization and rapid clearance from circulation by macrophages of the mononuclear phagocyte system, thus preventing pathological calcification. Accordingly, low levels of free serum fetuin-A and high serum CPPs are associated with pathological calcification in patients suffering from chronic kidney disease.