Formula-based estimates of the GFR: equations variable and uncertain.

in Nephron. Clinical Practice (2008), 110(1), 48-5354

Regarding the prevalence of chronic kidney disease in the population, estimation of glomerular filtration rate is of importance. Creatinine-based formulas are thus useful as the first step of a prevention ... [more ▼]

Regarding the prevalence of chronic kidney disease in the population, estimation of glomerular filtration rate is of importance. Creatinine-based formulas are thus useful as the first step of a prevention strategy. Several creatinine-based formulas have been published. Among these, the Cockcroft-Gault formula and the Modification of Diet in Renal Disease (MDRD) study equation are the most used by physicians. The latter may be automatically reported by laboratories and has thus great success. However, these formulas have limitations. First, the MDRD formulas are not applicable to all populations, notably the healthy one and the patients with abnormal weight (anorectic or obese). Second, we evoke the limitations in the precision of the formulas linked to analytical aspects. Indeed, these analytical limitations remain significant even if they are improved by creatinine standardization. Lastly, we briefly mention the potential impact of these limitations on the epidemiology and the staging of chronic kidney disease. [less ▲]

Indexation du DFG pour la surface corporelle: mythe et réalité.

Conference given outside the academic context (2008)

Cystatine C: point d'étape et perspectives

in Annales de Biologie Clinique (2008), 66(3), 301-23

Cystatin C is a low molecular weight-protein, which may replace creatinine for the evaluation of renal function, particularly in the clinical settings where the relationship between creatinine production ... [more ▼]

Cystatin C is a low molecular weight-protein, which may replace creatinine for the evaluation of renal function, particularly in the clinical settings where the relationship between creatinine production and muscular mass impairs the clinical performance of creatinine. This paper intends to summarize the current knowledge about the physiology of cystatin C and about its use as a renal marker, alone or within formulas developed to estimate the glomerular filtration rate. Moreover, this paper reviews the recent data about potential other applications of cystatin C, especially in cardiology, in oncology and in clinical pharmacology. [less ▲]

Acetylcysteine and Enzymatic Creatinine: Beware of Laboratory Artefact!

in Intensive Care Medicine (2007)

Stability of intact parathyroid hormone in samples from hemodialysis patients

in Kidney International (2007), 72(3), 370-372

The determination of intact parathyroid hormone levels is used for diagnosis and in the management of renal osteodystrophy. Pre-analytical and analytical conditions are important in the overall confidence ... [more ▼]

The determination of intact parathyroid hormone levels is used for diagnosis and in the management of renal osteodystrophy. Pre-analytical and analytical conditions are important in the overall confidence of the assay. Unfortunately, there are no clear recommendations for the use of serum samples or samples anticoagulated with ethylenediaminotetraacetic acid (EDTA) for the best preservation of intact parathyroid hormone. In our study, the Roche Elecsys assay was used to measure intact hormone in both serum and EDTA plasmas from 16 hemodialysis patients over the span of a month. Parathyroid hormone stability was determined in samples kept frozen for 1-5 days or after 8-24 h at room temperature. There was no difference in hormone stability between serum and EDTA samples after 1 day in frozen storage. After 5 days frozen, hormone degradation was significantly greater after EDTA anticoagulation than in serum aliquots. When samples were stored at room temperature, intact parathyroid hormone was significantly more stable in EDTA-treated samples than in clotted serum samples, especially after 24 h. We conclude that optimum results are achieved in the measurement of intact parathyroid hormone levels depending on the workflow of the lab. If the lab works with intermittent batches of samples, frozen serum is the best. If the lab services general practitioners and/or several hospitals and has a continuous flow of samples, EDTA-treated samples stored at room temperature are the best. [less ▲]

Evaluation of heterophile antibodies interference on Liaison PTH (Diasorin)

in Clinical Chemistry & Laboratory Medicine (2007, June), 45

Analytical variation in plasma renin activity: Implications for the screening of primary aldosteronism

in Clinical Chemistry (2007), 53(4), 803-804

MDRD equation for GFR estimation : analytical limitations

Conference (2007, March 23)

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 ▲]

Estimated glomerular filtration rate

in Annals of Internal Medicine (2007), 146(1), 74-74