Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Oct 16.
doi: 10.1007/s00467-025-06986-w. Online ahead of print.

Performance of creatinine and cystatin C-based equations to estimate glomerular filtration rate in African children with sickle cell anemia

Agathe Bikupe Nkoy  1   2 , Floreen Maluwenze Mumaka  3 , Therance Tobo Matoka  3 , Ange Ngonde  4 , Ernest Kiswaya Sumaili  5 , Justine Busanga Bukabau  5 , Veerle Labarque  6   7 , Lambertus P van den Heuvel  8   9 , Arend Bökenkamp  10 , Etienne Cavalier  11 , Elena Levtchenko  10 , Pierre Delanaye  12   13 , Hans Pottel  14 , Pépé Mfutu Ekulu  3
Affiliations

Performance of creatinine and cystatin C-based equations to estimate glomerular filtration rate in African children with sickle cell anemia

Agathe Bikupe Nkoy et al. Pediatr Nephrol. .

Abstract

Background: Serum creatinine (SCr), the most used biomarker to evaluate glomerular filtration rate (GFR), might be inaccurate in children with sickle cell anemia (SCA). In this context, cystatin C (SCys) could be of interest. This study evaluated the performance of commonly used SCr- and SCys-based estimated GFR (eGFR) equations in African children with SCA.

Methods: This cross-sectional study included 109 steady-state children with SCA aged 3-18 years, from the Democratic Republic of Congo. Measured GFR (mGFR) was obtained using iohexol plasma clearance. eGFR was calculated using commonly used SCr- and SCys-based equations in children. The performance of these equations was evaluated by calculating the bias, precision, and accuracy within 30% (P30) of mGFR.

Results: The mean age of participants was 9.9 ± 4.2 years, and 48.6% were female. The median mGFR was 142 (IQR 119-169) mL/min/1.73 m2. Of the equations studied, the FAS-Age SCr had the lowest bias (0.9 mL/min/1.73 m2). However, the 95% limit of agreement was very wide (-80.3 to + 81.6). SCr failed to rise in an age-dependent manner, reflecting a progressive loss of muscle mass or increased tubular secretion. All SCys-based equations underestimated GFR and failed to detect hyperfiltration, but there was no age-related change in bias.

Conclusion: These data show that all common eGFR equations using SCr or SCys poorly predict mGFR in African children with SCA. SCr-based equations potentially miss a decline in kidney function, which suggests that SCys could be the preferred marker in this population.

Keywords: Creatinine; Cystatin C; Equations; Glomerular filtration rate; Sickle cell anemia.

PubMed Disclaimer

Conflict of interest statement

Declarations. Conflict of interest: Pierre Delanaye and Etienne Cavalier are consultants for Nephrolyx. Hans Pottel is a consultant for Bayer. These funders were not involved in the design, analysis, presentation, or interpretation of the study results. None of the other authors have a relevant conflict of interest.

References

    1. Adebayo O, Nkoy A, Cheng C et al (2023) Sickle cell disease: a neglected haemoglobinopathy disorder with a huge global burden. Belg J Hematol 14:41–58
    1. Thomson AM, McHugh TA, Oron AP et al (2023) Global, regional, and national prevalence and mortality burden of sickle cell disease, 2000–2021: a systematic analysis from the Global Burden of Disease Study 2021. Lancet Haematol 10:e585–e599. https://doi.org/10.1016/S2352-3026(23)00118-7 - DOI
    1. Ataga KI, Saraf SL, Derebail VK (2022) The nephropathy of sickle cell trait and sickle cell disease. Nat Rev Nephrol 18:361–377. https://doi.org/10.1038/s41581-022-00540-9 - DOI - PubMed - PMC
    1. Adebayo OC, Van den Heuvel LP, Olowu WA et al (2022) Sickle cell nephropathy: insights into the pediatric population. Pediatr Nephrol 37:1231–1243. https://doi.org/10.1007/s00467-021-05126-4 - DOI - PubMed
    1. Zahr RS, Saraf SL (2024) Sickle cell disease and CKD: an update. Am J Nephrol 55:56–71. https://doi.org/10.1159/000534865 - DOI - PubMed

LinkOut - more resources