Is serum cystatin C a sensitive marker of glomerular filtration rate (GFR)?
Plebani M; Dall’Amico R; Mussap M; Montini G; Ruzzante N; Marsilio R; Giordano G; Zacchello G Department of Laboratory Medicine, Central Laboratory, Azienda Ospedaliera, Padova, Italy. Human cystatin C is a basic low molecular mass protein (13,359 Dalton) freely filtered through the glomerulus and almost completely re-absorbed and catabolized by proximal tubular cells. We measured serum cystatin C in 38 kidney transplant patients (23 males, 15 females) aged between 6 and 32 years. To assess renal function, serum and urinary creatinine were also determined in all patients, and creatinine clearance was finally calculated. Cystatin C was determined by a particle-enhanced turbidimetric assay, and creatinine was measured by gas chromatography-mass spectrometry. To compare the diagnostic efficiency of cystatin C with that of creatinine, inulin clearance was performed on 12 renal transplant patients, and receiver operating characteristic (ROC) analysis was applied.
