Trueness verification and traceability assessment of results from commercial systems for measurement of six enzyme activities in serum: An international study in the EC4 framework of the Calibration 2000 project

Results For ALT results were relatively good. > 95% of laboratories using systems from Dade, Olympus, Ortho and Roche are expected to comply traceability within the biologically derived limits, and 94% respectively 89% from Abbott and Beckman. For AST and GGT only Dade respectively Olympus fully complied. For CK all companies showed significant bias. Nevertheless > 95% of laboratories applying Abbott, Beckman and Roche systems will comply. Finally, LD and amylase measurements require significant improvement. Some manufacturers continue to sell on the European market assays giving results which are not traceable to the internationally accepted reference systems. Conclusions The traceability of enzyme measurements obtained with routine procedures to internationally accepted IFCC reference systems is not yet satisfactorily accomplished in clinical practice. Abbreviations EC4 European Communities Confederation of Clinical Chemistry and Laboratory Medicine IFCC International Federation of Clinical Chemistry and Laboratory Medicine IVD in vitro diagnostic ALT alanine aminotransferase AST aspartate aminotransferase CK creatine kinase GGT γ-glutamyl transferase LD lactate dehydrogenase EQAS external quality assessment scheme T target value SD bl between-laboratory variance SD wl within-laboratory variance SD bl max maximum allowable between-laboratory variance SD wl max maximum allowable within-laboratory variance AB desirable analytical bias SD d desirable analytical variation SD w within-person biological variation SD b between-person biological variation TAE total allowable error Keywords Enzymes Reference methods Calibration Bias Analytical error IVD Verification External quality assessment Routine methods