[The usefulness of plasma cystatin C determination as a marker of glomerular filtration rate].

Cystatin C is a low molecular weight protein; a cysteine proteinase inhibitor. As it is freely filtrated in the renal glomeruli, and not reabsorbed into circulation, therefore it may be used as a marker of glomerular filtration rate (GFR). We discuss clinical studies which were focused on the feasibility of plasma Cys C determination as a marker of GFR in various populations. Many of these studies suggest that plasma Cys C may be superior to plasma creatinine for the detection of patients with early decline in renal function. Recent data indicate, that Cys C may be a risk marker or factor of death or cardiovascular event in high-risk populations.