[Cystatin C as a marker of glomerular filtration rate]

The assessment of the glomerular filtration rate (GFR) is the most commonly used test of renal function. Cystatin C, a cysteine protease inhibitor, which can be measured by light scattering immunoassay, possesses many of the attributes required of the ideal GFR marker. This paper reviews so far obtained results dealing with cystatin C measurement, reference intervals and its diagnostic significance in nephropathy. Although serum cystatin C can generally be recommended as a marker of GFR, especially to detect mild GFR reductions, further clinical studies should be performed to confirm the validate in renal transplants and cancer patients.