ESPN 51th Annual Meeting

ESPN 2018


 
IOHEXOL PLASMA CLEARANCE IN CHILDREN: SINGLE-VERSUS MULTIPLE-SAMPLE METHOD (TO MEASURE GLOMERULAR FUNCTION RATE)
VANDREA CARLA DE SOUZA 1 LUCIANO DA SILVA SELISTRE 1 EMILIE BRES 2 BRUNO RACHIN 3 JUSTINE BACCHETTA 3 PIERRE COCHAT 3 LAURENCE DUBOURG 4

1- Mestrado de Ciências da Saúde -Universidade de Caxias do Sul- CAPES, Brazil
2- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, France
3- Centre de Référence des Maladies Rénales et Phosphocalciques Rares, Bron, France. 5- Université Claude Bernard Lyon 1, Lyon, France
4- Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, France. Université Claude Bernard Lyon 1, Lyon, France
 
Introduction:

Accurate and precise measurement of GFR is important for children with chronic kidney disease (CKD).Therefore a safe, simplified and accurate method of measurement of GFR (mGFR) is needed. Recently Tøndel et al.(Pediatr Nephrol. 2018;33:683-69) demonstrated that a single-point method (GFR1p) could be used as an alternative to the slope-GFR determination (GFRslope).The aim of this study was to evaluate in another population the performance of the GFR1pmeasurement compared to the GFRslope and determine the optimal sampling point.

Material and methods:

The mGFR was assessed in 899 children (1,336 measurements) with various CKD stages (median age 12.5 years [1.5-17.9]) by iohexol plasma clearance GFRslopeusing the Brøchner–Mortensen correction (early BSA normalization) as the reference method. Median GFRslope was 89 mL/min/1.73m[15-196]. The performance of two formulas (Fleming and Jacobsson-modified) was validated against the reference. Equation performance was assessed using bias and accuracy (percentage of estimated GFRs 10% (P10) limits above and below the measured GFR.

Results:

In the whole population the Fleming formula (3h and 4h) showed similar performance (GFR1p-3h bias 2.0 ml/min/1.73m[CI95% 1.0;2.5]; P10 93.0 % [CI95% 92.0;94.5]) and (GFR1p-4h bias 1.0 ml/min/1.73m[CI95% 0.5;1.5]; P10  92.0 % [CI95% 90.5;93.0]) whereas performance of Jacobsson-modified-4h could not be acceptable (bias -6.2 [CI95% -6.7;-5.7]; P10 66% [CI95% 64.0;69.0%]), p<0,001). In patients with a CKD stages II-IV (n=179), the performance of Fleming 4h was better than 3h (GFR1p-4h bias -3.5 mL/min/1.73m[CI95%-4.5;-2] and P10 85% [CI95% 82.5;92.5] and (GFR1p-3h bias -2.5 ml/min/1.73m[CI95% -3.5;-1.0]; P10 81.0 % [CI95% 75.5;86.0], (p =0.01) and better than the Jacobsson-modified-4h (bias -5.0 ml/min/1.73m[CI95% -6.0;-3.5] and P10 81.5% [CI95% 76.5;87.0], p=0.01).  

Conclusions:

For determination of mGFR in children with various CKD stages, the single-point (4h)-Fleming is highly concordant with a multiple-sample method, including when GFR is between 30 and 60 mL/min/1.73 m2.