Acta bioquímica clínica latinoamericana
versión impresa ISSN 0325-2957
PERAZZI, Beatriz y ANGEROSA, Margarita. Creatinine in blood: analytical quality and influence on the estimation of Glomerular Filtration Rate. Acta bioquím. clín. latinoam. [online]. 2011, vol.45, n.2, pp. 265-272. ISSN 0325-2957.
The glomerular filtration rate (GFR) is considered the best indicator of kidney function. Many national and international organizations recommend the use of equations that estimate the GFR to facilitate detection, evaluation, and management of chronic kidney disease (CKD). The "National Kidney Disease Education Program" (NKDEP) has developed a plan that enables standardization and improved accuracy of serum creatinine measurements that include the use of the estimated equation for GFR based on serum creatinine concentration developed from the "Modification of Diet in Renal Disease" (MDRD) study. In this equation, serum creatinine is the only measurement test. It is very important to achieve the measurement of creatinine because the bias for values that are within the 0.95 - 1.7 mg/dL range, corresponding to the estimated GFR near the 60 mL min-1. (1,73 m2), produce a significant impact on the estimated GFR values. In order to improve the performance of estimated GFR values, recommendations have been suggested by the NKDEP. These include recalibration of routine serum creatinine methods to be traceable to the reference method for creatinine, which is isotopedilution mass spectrometry (IDMS). This initiative is proposed to remove bias between methods and laboratories in order to compare the measurement of serum creatinine. In addition, the determination of serum creatinine by the method chosen according to the population in study needs to achieve <5% analytical bias, compared to an IDMS reference measurement procedure,and <8% analytical imprecision in order to set a total error goal for creatinine measurement to produce a maximum 10% error in estimated GFR.
Palabras clave : Creatinine; Analytical imprecision; Traceability; Estimation of Glomerular Filtration Rate.