John Libbey Eurotext

Néphrologie & Thérapeutique


Estimation of glomerular filtration rate in children: interest of FAS formula Volume 19, issue 1, February 2023


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1 CHU de Bordeaux, service de biochimie du laboratoire de biologie médicale, Place Amélie Rabat Léon, 33000 Bordeaux, France
2 Hôpital Pellegrin-Enfants, CHU de Bordeaux, service de néphrologie pédiatrique, Place Amélie Rabat Léon, 33000 Bordeaux, France
3 Université de Bordeaux, 146, rue Léo Saignat, 33076 Bordeaux, France
Correspondance : P. Ratouit

The recommended equation to estimate the value of glomerular filtration rate (eGFR) among children is Schwartz equation updated in 2009. However, it is few frequently used because involves height, a factor rarely documented for laboratories, especially hospital laboratories. The FAS (Full Aged Spectrum) formula developed by a European group, allows to get away from this factor. We compared CKD-EPI (Chronic Kidney Disease-EPIdemiology collaboration) and FAS formulas to Schwartz equation to estimate GFR in children. We realized a retrospective study included 1.668 children between 2 and 14 years old, whose serum creatinine had been measured during their hospitalization stay. We showed that FAS formula is correlated to Schwartz (r = 0.88), with a mean underestimation of eGFR at 6.2% versus CKD-EPI which has a correlation coefficient equal to 0.45 and overestimates eGFR to approximatively 42.0% compared to Schwartz formula. Furthermore, concordance at 30% is 99% with FAS whereas it’s only 35% with CKD-EPI. Thus, we recommend using the FAS formula to estimate GFR in children between 2 and 14 years old when their height is not available.