Abstract
Aim: Comparison of methods for determination of serum creatinine (SCr) and evaluation of the effect of the used method on estimation of glomerular filtration rate (eGFR) in children with kidney disease. Methods: We assessed SCr in 168 children (102 boys, age 1.7-15.9 years) by both, the Jaffe method and enzymatically. eGFR was estimated by Schwartz formula.
Results: The Jaffe method overestimated SCr at lower levels ( 250 μmol/L). Up to SCr of 60 μmol/L using Jaffe method, eGFR values were lower with higher SCr in comparison to enzymatic method as expected.
However, eGFR values were paradoxically higher in all patients with SCr above 100 μmol/L using Jaffe method. This paradox was especially evident in adolescent boys mainly due to the different F coefficient used for eGFR calculation.
Conclusion: Estimation of GFR depends on the accuracy of the SCr measurement and the F coefficient in the Schwartz formula. These effects can have serious clinical consequences, especially in children with advanced chronic kidney disease stages 4 and 5, when the enzymatic method provides significantly lower eGFR values, which may result in earlier initiation of dialysis treatment.