Estimating glomerular filtration rates: Updates and prospects

Résumé 0

A patient’s glomerular filtration rate (GFR) is estimated using equations that take into account serum or plasma concentrations of endogenous markers (creatinine and/or cystatin C) and demographic data (age, sex, ± ethnic origin). These equations are accurate at the population level, but frequently inaccurate at the individual level. The creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation published in 2009 (CKD-EPIcr-2009), and the CKD-EPI equation published in 2012 based on creatinine and cystatin C, were recalibrated in 2021 to remove their dedicated race correction factors for Black American subjects. All creatinine-based CKD-EPI equations overestimate true GFR in subjects under thirty. The Full Age Spectrum (FAS) equation, applicable across the entire age spectrum (from young children to the elderly), solved this problem, but remained suboptimal at low GFR values. The European Kidney Function Consortium (EKFC) equation published in 2021 was an improvement of the FAS equation. It also includes the Q factor (median creatinine in the general population). It is applicable across the age spectrum, and performs well at low and normal GFR values. The new creatinine-based CKD-EPI equation (CKD-EPIcr-2021) underestimates GFR in Black Americans and overestimates it in non-Black Americans. In European and African subjects, CKD-EPIcr-2021 overestimates true GFR and should not be adopted. The EKFC equation, which performs well in this population, also performs well in European Black subjects and in African subjects, provided dedicated Q factors are used.