Validation of an enzyme calibrator-an IFCC guideline

Objectives: The objective of this guideline is to improve standardization in clinical enzymology in order to improve intermethod comparability of patients’ results. Design and Methods: The reference system, combination of the reference method and the reference material, is used to produce a reference value for a given catalytic activity. Sets of methods are formed of methods exhibiting the same analytical specificity. Materials intended to be used as enzyme calibrators are experimentally checked for their commutability. Results: The transfer of accuracy from the reference value to patients’ results is dependent on methods (analytical specificity) and on materials (experimentally assessed commutability). The feasibility of this approach was demonstrated with materials of high level for several enzymes and for each of them for several routine methods. Conclusion: Expected advantages of this approach in clinical enzymology are presented.