Effect of differences in serum creatinine estimation methodologies on estimated glomerular filtration rate

Area of Science:

• Nephrology
• Clinical Chemistry
• Biomedical Engineering

Background:

• Serum creatinine is a key biomarker for estimating glomerular filtration rate (GFR).
• Variations in GFR estimation methods and laboratory devices introduce uncertainty in chronic kidney disease (CKD) prevalence and outcome prediction.
• Standardization efforts in serum creatinine measurement are ongoing.

Purpose of the Study:

• To investigate the impact of different laboratory devices on estimated GFR (eGFR) values derived from serum creatinine measurements.
• To quantify the variability in eGFR across different analytical platforms and creatinine assay methods.

Main Methods:

• Serum creatinine was measured in 163 participants using four different laboratory devices (Roche Cobas Integra 400, Beckman LX20, Hitachi 7180, Toshiba TBA-c8000).
• Both Jaffe and enzymatic creatinine methods were employed across the different devices.
• Participants were enrolled during a community health screening program.

Main Results:

• The proportion of participants with an eGFR < 60 mL/min/1.73 m² varied significantly by device: 11.04% (Roche Cobas Integra 400), 6.75% (Beckman LX20), 20.25% (Hitachi 7180), and 20.86% (Toshiba TBA-c8000).
• Specific combinations of device and method (e.g., Roche Cobas Integra 400 with enzymatic method) also yielded differing results.
• These discrepancies highlight device-dependent bias in eGFR calculations.

Conclusions:

• Despite standardization of serum creatinine measurement (e.g., using isotope dilution mass spectrometry), inter-device variability persists.
• Differences in laboratory devices introduce substantial bias, affecting the accurate estimation of CKD progression and patient outcomes.
• Standardized creatinine assays and device calibration are crucial for reliable GFR assessment.