Is serum cystatin C a sensitive marker of glomerular filtration rate (GFR)? A preliminary study on renal transplant patients.
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. The results of this study demonstrate that serum cystatin C significantly increases in renal transplant patients with reduced creatinine clearance (< 70 mL/min per 1.73 m2) and that the diagnostic accuracy of serum cystatin C is better than of serum creatinine. Cystatin C may be utilized as a very marker of reduced GFR.
Plebani
M
M
Department of Laboratory Medicine, Central Laboratory, Azienda Ospedaliera, Padova, Italy.
Dall'Amico
R
R
Mussap
M
M
Montini
G
G
Ruzzante
N
N
Marsilio
R
R
Giordano
G
G
Zacchello
G
G
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002648:Child; D003404:Creatinine / Q000097:blood / Q000652:urine; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D015853:Cysteine Proteinase Inhibitors / Q000097:blood*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005919:Glomerular Filtration Rate; D006801:Humans; D007444:Inulin / Q000097:blood / Q000652:urine; D007668:Kidney / Q000502:physiology*; D016030:Kidney Transplantation / Q000502:physiology; D008297:Male; D009391:Nephelometry and Turbidimetry; D011237:Predictive Value of Tests; D012372:ROC Curve
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D007444:Inulin; D003404:Creatinine