New data on the intraindividual variation of cystatin C.

in Nephron. Clinical Practice (2008), 108(4), 246-8

BACKGROUND: Cystatin C is a new interesting marker of glomerular filtration rate (GFR). However, data regarding its biological variance are scarce and conflicting. The ability of cystatin C to ... [more ▼]

BACKGROUND: Cystatin C is a new interesting marker of glomerular filtration rate (GFR). However, data regarding its biological variance are scarce and conflicting. The ability of cystatin C to longitudinally follow renal function in patients therefore remains questionable. METHODS: 12 healthy subjects (6 men and 6 women) were included in the final statistical analysis. Serum creatinine, plasma cystatin C and GFR were measured twice after a 1-week interval on the same day, at the same time, and under the same preanalytical and analytical conditions. GFR was measured with an iohexol method. Serum creatinine was measured with a compensated Jaffe and an enzymatic method. Plasma cystatin C was measured by a particle-enhanced immunonephelometric method. Analytical (CV(A)) and within-subject (CV(I)) variances were classically calculated. RESULTS: CV(A) for creatinine (Jaffe and enzymatic methods) and cystatin C was 2.5, 0.97 and 1.29%, respectively. CV(I) was 5.8, 5 and 4.5% for the Jaffe creatinine, enzymatic creatinine and cystatin C determinations, respectively. CONCLUSION: Our study confirms that intraindividual variation of cystatin C and creatinine are similar. Therefore, from a biological point of view, cystatin C seems as accurate as creatinine for the longitudinal follow-up of renal function in daily clinical practice. [less ▲]

Is cystatin C useful for the detection and the estimation of low glomerular filtration rate in heart transplant patients?

in Transplantation (2007), 83(5), 641-644

Although previously studied in patients with chronic kidney disease, there is less data for the use of cystatin C and cystatin C-based formulas in heart transplant recipients. The ability of creatinine ... [more ▼]

Although previously studied in patients with chronic kidney disease, there is less data for the use of cystatin C and cystatin C-based formulas in heart transplant recipients. The ability of creatinine and cystatin C to detect renal failure (glomerular filtration rate [GFR] below 60 mL/min/1.73 m(2)) in heart transplant patients has been compared. The accuracy and precision of a creatinine-based formula (Modification of Diet in Renal Disease [MDRD]) versus a cystatin C-based formula (Rule's formula) to estimate GFR have also been studied. GFR was measured using the (51)Crethylenediamine tetraacetic acid tracer in 27 patients. There was no significant difference between GFR and the reciprocal of creatinine or cystatin C. Receiver operating characteristic curves for cystatin C and creatinine were similar. Both formulas were well correlated with the GFR. The bias of the cystatin C-based was significantly better than one of the MDRD formula, but the standard deviation appeared better for the MDRD formula (bias of +3.9 mL/min/1.73 m(2) versus +12 mL/min/1.73 m(2) and SD of 8.5 versus 11.6, respectively). Plasma cystatin C has no clear advantage over serum creatinine to detect renal failure in heart transplanted patients. [less ▲]

Variabilité du débit de filtration glomérulaire, de la créatinine et de la cystatine C plasmatiques

in Néphrologie & Thérapeutique (2007), 3(5), 037

Plasma cystatin C for the detection of renal failure in obese patients

in Nephrology Dialysis Transplantation (2006), 21(S4), 214

Creatinine-based formulae for the estimation of glomerular filtration rate in heart transplant recipients

in Clinical Transplantation (2006), 20(5, Sep-Oct), 596-603

Chronic renal failure (CRF) is a common complication in heart transplant patients. Serum creatinine has clear limitations for the detection and estimation of glomerular filtration rate (GFR). Various ... [more ▼]

Chronic renal failure (CRF) is a common complication in heart transplant patients. Serum creatinine has clear limitations for the detection and estimation of glomerular filtration rate (GFR). Various creatinine-based formulae are classically used for GFR estimation, but little scientific evidence exists for such use in a heart transplant population. GFR was measured using the plasmatic clearance of the glomerular tracer Cr-51-EDTA in 27 heart transplant patients with two measures for 22 of the patients. Forty-nine measures were thus available for analysis. The precision and accuracy (Bland and Altman analysis) of the Cockcroft, simplified Modified Diet in Renal Diseases (MDRD) and new Mayo Clinic formulae were compared. The mean GFR of the population was 39 +/- 15 mL/min/1.73 m(2). All formulae were well correlated with the GFR. With the Bland and Altman analysis, the accuracy of the MDRD formula appeared higher than that of the Cockcroft or the Mayo Clinic formulae (bias of +12 mL/min/1.73 m(2), vs. +19.9 mL/min/1.73 m(2), and +22.1 mL/min/1.73 m(2), respectively). The difference between the estimated and measured GFR was higher than 20 mL/min/1.73 m(2) in 51% and 55% cases when using the Cockcroft and the Mayo Clinic formulae respectively, whereas the difference was only noted in 14% cases when the MDRD was used. Among creatinine-based formulae, the MDRD appears the most precise and accurate for estimating the GFR in heart transplant patients. However, when the GFR must be measured with high accuracy, we recommend the use of a reference method like inulin or Cr-51-EDTA plasma clearance techniques. [less ▲]

F-18-FDG PET in children with lymphomas

in European Journal of Nuclear Medicine and Molecular Imaging (2005), 32(1), 31-38

Purpose: The aim of this study was to retrospectively evaluate the performance of positron emission tomography (PET) with F-18-fluorodeoxyglucose (F-18-FDG) in children with lymphomas, at various stages ... [more ▼]

Purpose: The aim of this study was to retrospectively evaluate the performance of positron emission tomography (PET) with F-18-fluorodeoxyglucose (F-18-FDG) in children with lymphomas, at various stages of their disease. Methods: Twenty-eight children (mean age 12.5 years, 14 girls, 14 boys) with Hodgkin's disease (HD, n=17) or non-Hodgkin's lymphoma (NHL, n= 11) were evaluated. Patients were investigated at initial staging (n=19), early in the course of treatment (n=19), at the end of treatment (n=16) and during long-term follow-up (n=19). A total of 113 whole-body PET studies were performed on dedicated scanners. PET results were compared with the results of conventional methods (CMs) such as physical examination, laboratory studies, chest X-rays, computed tomography, magnetic resonance imaging, ultrasonography and bone scan when available. Results: At initial evaluation (group 1), PET changed the disease stage and treatment in 10.5% of the cases. In early evaluation of the response to treatment (group 2), PET failed to predict two relapses and one incomplete response to treatment. In this group, however, PET did not show any false positive results. There were only 4/75 false positive results for PET among patients studied at the end of treatment (group 3, specificity 94%) or during the systematic follow-up (group 4, specificity 95%), as compared with 27/75 for CMs (specificity 54% and 66%, respectively). Conclusion: F-18-FDG-PET is a useful tool for evaluating children with lymphomas. Large prospective studies are needed to appreciate its real impact on patient management. [less ▲]

Estimation de la fonction rénale chez le patient anorexique

in Diabètes & Métabolism (2004), 30

Detection of renal failure in overweight patients.

in Kidney International (2004)

Estimation of renal function in anorexia nervosa

in Kidney International (2004)