Detection and quantification of circulating immature platelets: agreement between flow cytometric and automated detection.

Immature platelets-also termed reticulated platelets (RP)-are platelets newly released into the circulation, and have been associated with a variety of pathological thrombotic events. They can be assessed by flow cytometry after staining with thiazole orange (TO) or by using a module added to a fully automated analyzer that is currently in wide clinical use and expressed as a fraction of the total platelet count (IPF). We sought to assess the correlation and agreement between these two methods.