Correlation of cystatin C and creatinine based estimates of renal function in children with hydronephrosis

Area of Science:

• Pediatric Nephrology
• Biomarkers in Renal Function Assessment
• Clinical Chemistry

Background:

• Accurate and rapid estimation of glomerular filtration rate (GFR) is crucial for clinical management of renal function.
• Current GFR estimation methods, particularly those relying on serum creatinine, have limitations in pediatric populations.

Purpose of the Study:

• To evaluate the association between a GFR estimating equation based solely on cystatin C (Gentian equation) and one based solely on creatinine (Schwartz equation) in children.
• To determine the clinical utility of cystatin C as a marker for GFR estimation in pediatric patients.

Main Methods:

• A cohort of 31 children aged 1 day to 5 years with hydronephrosis was enrolled.
• Glomerular filtration rate (GFR) was calculated using both the Schwartz equation (creatinine-based) and the Gentian equation (cystatin C-based).
• Statistical analysis, including Pearson correlation coefficient, was used to compare the two methods.

Main Results:

• Mean GFR estimated by the Schwartz equation was 70.19 ± 24.86 ml/min/1.73 m(2), while the Gentian equation yielded 86.97 ± 21.57 ml/min/1.73 m(2).
• A strong direct association was observed between GFR values from both equations (r = 0.594, P < 0.001).
• This correlation remained significant after adjusting for age and gender (r = 0.724, P < 0.001), with a linear relationship: Cystatin C GFR = 50.8 + 0.515 × Schwartz GFR.

Conclusions:

• The cystatin C-based Gentian equation demonstrates comparability with the creatinine-based Schwartz equation for estimating GFR in children.
• Cystatin C presents a viable alternative marker for assessing renal function in pediatric patients.
• The study highlights the potential of cystatin C in simplifying and improving the accuracy of GFR estimation in children.