Inter-laboratory validation of a harmonized PNH flow cytometry assay.

Background: A network comprising 11 laboratories aimed to consolidate PNH testing by developing and validating an assay guided by previous guidelines and studies. Network analyses of >20 native samples yielded key findings that were used to create and reshape the final protocol.

Methods: Twenty-seven native samples were distributed to all participating laboratories for blind testing, local analysis, and subsequent re-analysis by a central laboratory.