What question did this study set out to answer?

The study aims to evaluate the comparability of Jaffe and enzymatic creatinine methods and bilirubin's impact on clinical decision-making.

March 6, 2026Swiss Medical Weekly0 citationsOpen Access

Bilirubin interference in creatinine assays: cross-sectional analysis of the impact on the MELD score and CKD staging using Jaffe vs enzymatic methods

KFKathrin FreyUniversity Hospital of Zurich JGJoanna GawineckaUniversity Hospital of Zurich AEArnold Von EckardsteinUniversity Hospital of Zurich

Key Points

The study aims to evaluate the comparability of Jaffe and enzymatic creatinine methods and bilirubin's impact on clinical decision-making.
Compared creatinine measurements from Jaffe and enzymatic assays in routine heparin plasma samples.
Analyzed samples for bilirubin levels to estimate clinical impact on kidney disease staging.
Utilized a cross-sectional design with a large sample size of 15,618.
The Jaffe and enzymatic methods showed a mean relative bias of 3.97% in non-icteric samples.
In icteric samples with bilirubin levels of 5–20 mg/dl, the bias was 10.9%; for 20–53 mg/dl, it was 43.4%.
Increased MELD scores and kidney function underestimation were linked to Jaffe method susceptibility.

Abstract

BACKGROUND: Reliable and accurate measurement of creatinine is essential for the estimation of kidney function (eGFR) and for survival prediction with the model of the end-stage liver disease (MELD) score. Bilirubin interference is considered an important interference of Jaffe creatinine assays; the enzymatic assay is also affected but less so. This study aimed to evaluate the comparability of the Jaffe and enzymatic creatinine methods and the impact of their discrepancy on clinical decision-making, particularly in the context of bilirubin interference. METHODS: We compared creatinine measurements from the Roche Jaffe Gen.2 (CREJ2) and Roche Creatinine Plus ver.2 (CREP2) assays using routine heparin plasma samples (n = 15,618). To estimate the clinical impact of bilirubin interference on these two assays, we evaluated our results in the context of eGFR-based staging of severity of kidney disease and the MELD score. RESULTS: The Roche Jaffe and enzymatic methods agree well for non-icteric samples with a mean relative bias of 3.97% but not in icteric samples. In samples with 5–20 mg/dl and 20–53 mg/dl bilirubin, the biases amounted to 10.9% and 43.4%, respectively. CONCLUSIONS: The Jaffe method’s susceptibility to bilirubin interference, in comparison to the enzymatic assay, can result in higher MELD scores and can lead to an underestimation of kidney function.

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