Comparing the accuracy of creatinine - and cystatin С based equations in diagnosing and staging pediatric chronic kidney disease in clinical practice

Authors

DOI:

https://doi.org/10.15574/PS.2026.1(90).8893

Keywords:

chronic kidney disease in children under 25 equation, creatinine, cystatin C, estimated glomerular filtration rate, chronic kidney disease, children

Abstract

Estimated glomerular filtration rate (еGFR) plays a crucial role in management of pediatric patients; however, there is still a paucity of data regarding benefits of tailored use of eGFR equations in different subgroups of pediatric patients.

Aim - to compare the eGFR of children using creatinine and cystatin C based equations, to evaluate clinical accuracy in diagnosing and staging pediatric chronic kidney disease (CKD).

Materials and methods. The retrospective controlled study of 33 pediatric patients aged from 2 to 18 years was carried out over the period from 2023 to 2025. All patients underwent comprehensive clinical examination and work up to evaluate eGFR.

Results. CKD in children under 25 equation (CKiD U25) creatinine or cystatin has shown moderate-to-strong positive correlation with CKiD U25 cystatin C-creatinine (rs=0.6791; rs=0.9334). Patients whose eGFR was estimated using CKiD U25 creatinine have 3,6 times the odds of being misdiagnosed than those estimated with CKiD U25 cystatin C. The proportion of females misdiagnosed with CKiD creatinine was significantly higher in comparison to CKiD cystatin C (37.5% (6/16); 6.2% (1/16), respectively, p=0.0322).

Conclusions. The tailored approach of eGFR measurement should be utilized in pediatric practice using available validated eGFR equations. Female pediatric patients may significantly benefit from evaluating eGFR based on cystatin C or creatinine/cystatine C (Cre/Cys) combined equations. Utilizing the same CKiD U25 equation during the follow-up of pediatric patients in low-resource settings may prevent bias in CKD staging in the long-term management of pediatric patients with CKD.

The research was carried out in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the Local Ethics Committee of participating institution. The informed consent of the patient was obtained for conducting the studies.

No conflict of interest was declared by the authors.

References

Björk J, Nyman U, Larsson A et al. (2021). Estimation of the glomerular filtration rate in children and young adults by means of the CKD-EPI equation with age-adjusted creatinine values. Kidney International. 99(4): 940-947. https://doi.org/10.1016/j.kint.2020.10.017; PMid:33157151

Chevalier RL. (2023). CAKUT: A Pediatric and Evolutionary Perspective on the Leading Cause of CKD in Childhood. Pediatr Rep. 15(1): 143-153. https://doi.org/10.3390/pediatric15010012; PMid:36810342 PMCid:PMC9944871

Cirillo L, De Chiara L, Innocenti S et al. (2023). Chronic kidney disease in children: an update. Clin Kidney J. 16(10): 1600-1611. https://doi.org/10.1093/ckj/sfad097; PMid:37779846 PMCid:PMC10539214

Czarniak P, Zurowska A. (2014). Treatment strategies to prevent renal damage in hypertensive children. Curr Hypertens Rep. 16(4): 423. https://doi.org/10.1007/s11906-014-0423-2; PMid:24522942 PMCid:PMC3960483

El-Achkar TM, Eadon MT, Kretzler M et al. (2024). Precision Medicine in Nephrology: An Integrative Framework of Multidimensional Data in the Kidney Precision Medicine Project. Am J Kidney Dis. 83(3): 402-410.

Francis A, Shroff R, Earley A et al. (2025). KDIGO 2024 Guidelines-Key Points for Pediatricians. JAMA Pediatr. 179(2): 114-116. https://doi.org/10.1001/jamapediatrics.2024.5274; PMid:39621318

Inker LA, Tighiouart H, Adingwupu OM et al. (2024). Performance of GFR Estimating Equations in Young Adults. American Journal of Kidney Diseases. 83(2): 272-276. https://doi.org/10.1053/j.ajkd.2023.06.008; PMid:37717845 PMCid:PMC11080956

Knight EL, Verhave JC, Spiegelman D et al. (2004). Factors influencing serum cystatin C levels other than renal function and the impact on renal function measurement. Kidney Int. 65(4): 1416-1421. https://doi.org/10.1111/j.1523-1755.2004.00517.x; PMid:15086483

Lombel RM, Brakeman PR, Sack BS et al. (2022). Urologic Considerations in Pediatric Chronic Kidney Disease. Advances in Chronic Kidney Disease. 29(3): 308-317. https://doi.org/10.1053/j.ackd.2022.02.006; PMid:36084977

MdCalc. (2021). Chronic Kidney Disease in Children (CKiD) U25 eGFR Calculator. URL: https://www.mdcalc.com/calc/10574/chronic-kidney-disease-children-ckid-u25-egfr-calculator.

Ng DK, Pierce CB. (2021). Kidney Disease Progression in Children and Young Adults With Pediatric CKD: Epidemiologic Perspectives and Clinical Applications. Semin Nephrol. 41(5): 405-415. https://doi.org/10.1016/j.semnephrol.2021.09.002; PMid:34916001 PMCid:PMC8694646

Pierce CB, Muñoz A, Ng DK et al. (2021). Age- and sex-dependent clinical equations to estimate glomerular filtration rates in children and young adults with chronic kidney disease. Kidney Int. 99(4): 948-956. https://doi.org/10.1016/j.kint.2020.10.047; PMid:33301749 PMCid:PMC9083470

Pizzo H, Nguyen J, Schwartz GJ et al. (2024). Comparison of estimated GFR using cystatin C versus creatinine in pediatric kidney transplant recipients. Pediatr Nephrol. 39(7): 2177-2186. https://doi.org/10.1007/s00467-024-06316-6; PMid:38427073 PMCid:PMC11147893

Raikou VD. (2024). Renoprotective strategies. World J Nephrol. 13(1): 89637. https://doi.org/10.5527/wjn.v13.i1.89637; PMid:38596266 PMCid:PMC11000037

Tapper M, McGrowder DA, Dilworth L et al. (2021). Cystatin C, Vitamin D and Thyroid Function Test Profile in Chronic Kidney Disease Patients. Diseases. 9(1): 5. https://doi.org/10.3390/diseases9010005; PMid:33401560 PMCid:PMC7838907

Vakulenko LI. (2021). Effectiveness of nephroprotective therapy in children with chronic pyelonephritis in the follow-up observation. Child's health. 13(2): 165-170. https://doi.org/10.22141/2224-0551.13.2.2018.129549

White CA, Akbari A, Allen C et al. (2021). Simultaneous glomerular filtration rate determination using inulin, iohexol, and 99mTc-DTPA demonstrates the need for customized measurement protocols. Kidney International. 99(4): 957-966. https://doi.org/10.1016/j.kint.2020.06.044; PMid:32750458

Downloads

Published

2026-03-28

Issue

Section

Original articles. Urology and gynecology