[Could cystatine C replace creatinine as a market of glomerular filtration rate?].
Measurement of glomerular filtartion rate (GFR) is crucial for the detection and follow-up of an early renal impairment. Inulin clearance or radio-isotopes are the gold standard but they cannot be used routinely. Serum creatinine and creatinine clearance are the most widely used, but they lack sensibility to detect an early renal impairment and in cases of obesity, malnutrition or advanced age. Looking for a more reliable marker is necessary and cystatin C seems to be interesting. This molecule is constantly produced by nucleated cells, then freely filtrated and catabolized in the proximal tube. Clinical studies showed that cystatin C might be a more reliable marker of GFR in determined groups of patients. Moreover this molecule may have an other interest as a predictive risk factor or mortality, especially for cardiovascular events.