Flow cytometric assessment of measurable residual disease in acute myeloid leukaemia: a summary of current Australasian practice and future directions.

Multiparametric flow cytometry (MFC) enables rapid and sensitive quantification of measurable residual disease (MRD) in patients with acute myeloid leukaemia (AML), providing valuable prognostic information and guiding post-remission therapeutic strategies. Given the clinical utility of MFC AML MRD assessment and its inherent technical and analytical complexity, inter-laboratory standardisation is essential to ensure consistency of practice, diagnostic accuracy and reproducibility of results. However, limited options for external quality assessment exist. Representatives from all diagnostic laboratories in Australia and New Zealand currently performing AML MRD testing were invited to attend an in-person workshop to review site-specific practices and develop harmonisation processes. All six participating laboratories demonstrated a high level of concordance with respect to pre-analytical testing; however, greater variation was observed in post-analytical reporting, and a number of consensus recommendations were formulated for harmonisation. Ongoing meetings have also been established to promote continued sharing of expertise between AML MRD laboratories, align analytical strategies and enhance assay validation in accordance with regulatory requirements. These collaborative efforts provide guidance to existing MRD laboratories and those seeking to establish a new MRD service, facilitating sustainable provision of a high-quality regional MFC AML MRD testing network to meet current and anticipated increases in clinical demand.