Comparison of Jaffe Method and Enzymatic Method at Measuring Serum Creatinine Level, Creatinine Clearance and Estimated Glomerular Filtration Rate

BACKGROUND: Correct measuring of blood and urine creatinine level is necessary for identification and tracking of chronic kidney disease (CKD). OBJECTIVE: The aim of this study is a comparison of Jaffe and enzymatic methods for measuring creatinine in serum and in urine, in order to determine whether there are any statistical significant differences between them, and whether they are reflected on creatinine clearance calculation and estimated glomerular filtration rate (eGFR). METHODS: Creatinine in serum and urine was measured for the group of patients (N=60; female=34, male=26) from 24 to 69 years of age by using Jaffe’s method on Dimension RxL biochemical analyzer, and enzymatic method on integrated biochemical and immunochemical analyzer Architect ci8200, and obtained levels are used for creatinine clearance calculation and eGFR. RESULTS: The methods correlate well, both in measuring serum creatinine (r (1) = 0.990) and in measuring urine creatinine (r (2) =0.974). There are no statistically significant differences between them (p=0.57). Measuring creatinine using different methods showed no statistically significant differences in the calculated clearances (p=0.93), they significantly correlate (r=0.9722). eGFR, using the MDRD and CKD-EPI formulas, were not statistically significantly different, regardless of the used method. CONCLUSION: Apart from significant correlations between the used methods, the results of using the Jaffe and enzymatic methods showed no significant differences at measuring serum creatinine level, or creatinine clearance and glomerular filtration rate.