title: Evaluation of renal function in intensive care: plasma cystatin C vs. creatinine and derived glomerular filtration rate estimates.
abstract: Plasma cystatin C, a new marker of glomerular filtration rate (GFR), was prospectively evaluated in surgical intensive care. Cystatin C was measured (immunonephelometry, Dade-Behring) in 10 patients selected to cover a full range of GFR (phase I) and in 28 unselected consecutive patients followed for 5 days post-admission (phase II). Results were compared with (51)Cr-EDTA clearance (phase I only), plasma creatinine (kinetic Jaffe, Roche), 24-h or estimated by Cockcroft and Gault (CG) creatinine clearance (CrCl), and modified diet in renal disease (MDRD)-estimated GFR. In phase I, the highest correlation with(51)Cr-EDTA clearance (22-198 mL/min) was noted for CG CrCl (r(2): 0.883, p<0.001). During phase II follow-up, 24-h CrCl could not be calculated in 25% of daily evaluations. Cystatin C correlated with creatinine (0.856, p<0.0001) and CG CrCl with MDRD GFR (0.926, p<0.0001) in renal failure (10-78 mL/min, n=60). There was a +40% (p<0.001) median difference between cystatin C and creatinine (as a % of upper normal cut-off). Sensitivity/specificity to detect a <80 mL/min CG CrCl was 88/97% for cystatin C vs. 48/100% for creatinine (laboratory cut-off). In patients with normal and stable renal function (n=14), day-to-day intra-individual variation was 7.4% for cystatin C (vs. 10.6% for creatinine). In intensive care unit surgical adult patients, CG CrCl provides an easy and cost-effective estimate of GFR. Superior to creatinine, plasma cystatin C can be measured in selected patients where CG CrCl is known to be inaccurate.
authors.affiliation: Laboratoire de Biochimie A, Hôpital St-Louis (AP-HP), 1 avenue Claude Vellefaux, 75010 Paris, France. thierry.le-bricon@sls.ap-hop-paris.fr
authors.forename: Thierry
authors.initials: T
authors.lastname: Le Bricon
authors.forename: Isabelle
authors.initials: I
authors.lastname: Leblanc
authors.forename: Mourad
authors.initials: M
authors.lastname: Benlakehal
authors.forename: Cécile
authors.initials: C
authors.lastname: Gay-Bellile
authors.forename: Danielle
authors.initials: D
authors.lastname: Erlich
authors.forename: Said
authors.initials: S
authors.lastname: Boudaoud
mesh_terms: D015415:Biomarkers / Q000097:blood / Q000652:urine; D003404:Creatinine / Q000097:blood* / Q000652:urine; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007362:Intensive Care Units; D007668:Kidney / Q000502:physiology* / Q000503:physiopathology; D008297:Male; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000097:blood* / Q000175:diagnosis; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine