Analytical evaluation of Radiometer ABL90 FLEX PLUS enzymatic creatinine assay

Abstract

Background: The diagnosis of kidney disease strongly relies on accurate and reproducible measurements of creatinine, even when performed with point of care testing (POCT) devices. Therefore, this study aimed at performing a comprehensive evaluation of the analytical performance of a creatinine enzymatic assay on the Radiometer ABL90 FLEX PLUS. Methods: This analytical evaluation encompassed the assessment of intra-assay, inter-assay and total imprecision, along with linearity on routine lithium-heparin plasma samples. Method comparison was also carried out using results generated with Radiometer ABL90 FLEX PLUS in heparinized whole blood and those obtained in paired heparinized plasma with a reference enzymatic creatinine assay and a Jaffe method, both assayed on Roche Cobas c702. Results: The intra-assay imprecision of Radiometer ABL90 FLEX PLUS creatinine enzymatic assay was between 0.33–1.26%, the inter-assay imprecision between 0.64–1.78%, thus yielding a total imprecision of 0.79–1.99%. The linearity of the assay was excellent (r=1.000; P Conclusions: The results of this analytical evaluation confirm that Radiometer ABL90 FLEX PLUS creatinine enzymatic assay is at least as suitable as a conventional clinical chemistry enzymatic technique for routine and urgent diagnosis of kidney diseases.