Paediatric Surgery (Ukraine). 2026. 1(90): 88-93. doi: 10.15574/PS.2026.1(90).8893
Suchok S. O.¹, Yakymenko O. G.¹, Guminska G. S.^2
1 National Pirogov Memorial Medical University, Vinnytsia, Ukraine
²CNE "Vinnytsia Regional Children's Clinical Hospital", Ukraine

For citation: Suchok SO, Yakymenko OG, Guminska GS. (2026). Comparing the accuracy of creatinine – and cystatin С based equations in diagnosing and staging pediatric chronic kidney disease in clinical practice. Paediatric Surgery (Ukraine). 1(90): 88-93. doi: 10.15574/PS.2026.1(90).8893.
Article received: Oct 10, 2025. Accepted for publication: Mar 16, 2026.

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 (r_s=0.6791; r_s=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.
Keywords: chronic kidney disease in children under 25 equation, creatinine, cystatin C, estimated glomerular filtration rate, chronic kidney disease, children.

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