Simple Cystatin C–Based Prediction Equations for Glomerular Filtration Rate Compared with the Modification of Diet in Renal Disease Prediction Equation for Adults and the Schwartz and the Counahan–Barratt Prediction Equations for Children

Abstract

Background: Serum creatinine is the most commonly used marker for estimation of glomerular filtration rate (GFR). To compensate for its drawbacks as a GFR marker, several prediction equations including several parameters are being used, with the Modification of Diet in Renal Disease (MDRD), Schwartz, and CounahanBarratt equations being the ones most widely accepted for estimation of relative GFR in mL ⅐ min ؊1 ⅐ (1.73 m 2 ) ؊1 . The present study analyzes whether these GFR prediction equations for adults and children might be replaced by simple prediction equations based on plasma concentrations of cystatin C. Methods: Data from 536 patients (0.3-93 years), consecutively referred for determination of GFR by an invasive gold standard procedure, were used for the analysis. Calculations of bias (median percentage of error), correlation (adjusted R 2 ), and percentage of estimates within 30% and 50% of measured GFR were used in the comparisons. Results: A cystatin C-based prediction equation using only concentration in mg/L and a prepubertal factor:

Monitoring renal function: measured and estimated glomerular filtration rates - a review

“…In contrast to the MDRD equation, which was calculated from a large population in a multicenter study, CysC-based equations were created and validated in smaller samples using different gold standard measurements for GFR. Table 3 highlights some CysCbased equations for adults (29,45,(51)(52)(53)(54)(55)(56).…”

“…The vast majority, when comparing bias, precision, accuracy, and correlation, found CysC-based equations to be superior to creatinine-based equations as estimates of GFR (45,52,53), while some reported no difference in the performance of CysC-and creatinine-based equations (29,54). Recently, in order to improve the estimated kidney function, estimated GFR equations were developed, which incorporate both SCr and CysC.…”

Diagnostic Accuracy of Cystatin C–Based eGFR Equations at Different GFR Levels in Children

“…Serum cystatin C is a relatively new endogenous marker that offers the advantage of a constant production by all nucleated body cells and its almost entire catabolism at the proximal tubule (1). In clinical studies, serum cystatin C has been found to be a good marker for predicting GFR (2)(3)(4)(5)(6)(7)(8)(9).…”

Controle da hiperfosfatemia na DRC

“…Some of the formulas involving cystatin C presented better 20,47,48 or similar 27,49 performances in relation to the equations with creatinine, according to researchers. For some, the combination of serum creatinine and cystatin C in formulas is the best option when considering demographic data.…”

“…Against the expectation of being a proper marker, in this group, formulas based on cystatin C overestimate GFR in individuals with higher body mass index (BMI). 46 It is important to emphasize that some formulas have been developed in the past few years with the objective to better evaluate renal function with cystatin C, just as with serum creatinine, to estimate GFR, 20,22,27,[47][48][49][50][51] as demonstrated in Table 2.…”