Biologic sex and the estimation of GFR in pediatric and young adult patients with acute kidney injury

Should We Switch to the U25 Creatinine and CysC eGFR to Monitor Pediatric Kidney Transplant Recipients?

“…In those with a measured GFR >75 mL/min/1.73 m 2 , there is no consensus about which formula to use in adolescents and young adults (AYA) aged 18-30 years (or even 40, as suggested by Pottel) [14,15,18,19]. Studies with gold standard mGFR are becoming scarce, especially in kidney transplant recipients.…”

“…Any regression analysis only works well in the range where the data are generated [13]. Switching from the CKiD U25 formula to the adult CKD-EPI formula leads to an implausible increase in eGFR [12,14,15]. Using age-and sex-based average creatinine measurements, Hans Pottel introduced the full age spectrum (FAS) formula, derived from GFR measurements of 735 children and adolescents, 4371 adults, and 1764 older adults in Europe.…”

“…Since most patients had an mGFR below 75 mL/min/1.73 m 2 , the U25 CKiD formula worked reasonably well. However, this may differ in the normal or hyperfiltration range, where several manuscripts have outlined problems[12,14], and the work by Lindvig et al[20], requires some points:…”