INTERNATIONAL-FEDERATION-OF-CLINICAL-CHEMISTRY STANDARDIZATION PROJECT FOR THE MEASUREMENT OF LIPOPROTEIN(A) - PHASE-I - EVALUATION OF THE ANALYTICAL PERFORMANCE OF LIPOPROTEIN(A) ASSAY SYSTEMS AND COMMERCIAL CALIBRATORS

A secondary reference material for lipoprotein(a) is required to stand ardize the measurement of lipoprotein(a) in clinical laboratories worl dwide. Towards this aim, the International Federation of Clinical Chem istry Working Group for the Standardization of Lipoprotein(a) Assays h as initiated a standardization project involving a total of 33 diagnos tic company and clinical chemistry laboratories from 12 countries. In Phase 1, the analytical performance of 40 lipoprotein(a) assay systems was evaluated by testing sera and manufactured lipoprotein(a) calibra tor materials for precision, linearity, and parallelism. Twenty test s ystems were nonoptimized according to the results for a pooled serum, which tested nonlinear in 16 systems and imprecise in 4. Acceptable an alytical properties and harmonization of lipoprotein(a) values were sh own by some commercial calibrators, suggesting their possible use as r eference materials. This study highlights the problems that currently occur for lipoprotein(a) measurement in existing assay systems.