Background: Commutability of immunoassay test results is an important objective for laboratory medicine.
Methods: PSA is a clinically important analyte for which, as a consequence of a number of national and international initiatives over the last decade, considerable progress has been made towards improving method comparability. However, results from different assays are still not interchangeable, a situation that is only likely to improve once broad recommendations can be made about the most clinically relevant antibody combinations.
Conclusions: Universal implementation of such recommendations would almost certainly improve between-method agreement substantially, provided careful attention were paid to assay design and use of appropriately pure secondary standards ensured.