[Common, standardized and recommended approaches in the diagnosis and monitoring of paroxysmal nocturnal haemoglobinuria using flow cytometry].

Paroxysmal nocturnal hemoglobinuria is an acquired clonal disease characterized by proliferation of stem cells, deficient of proteins linked to the membrane via glycophosphatidylinositol (GPI) anchors. PNH cell characterization by flow cytometry was introduced in 1986, since 1996 is considered as method of choice for PNH diagnosis. Flow cytometry PNH analysis is nowadays crucial for disease monitoring in terms of progression, regression, remission or response to therapy and screening for small PNH clones (< 1.0%) in patients with aplastic anemia or myelodysplastic syndrome. Flow cytometry is unfortunately still poorly standardized, there is a variety of different methodological approaches for PNH evaluation and results from external quality assurances schemes reveal heterogeneous results. The aim of this work is to review the applicability of flow cytometry for the diagnosis and monitoring of PNH with respect to our experience and in the context of the recent trends and guidelines for PNH evaluation by flow cytometry.