Phagocytic capacity of monocyte-derived macrophages from ITP patients and healthy controls. Platelets were isolated, labeled with the cell tracker CMFDA, opsonized with W6/32 antibody, incubated with monocyte-derived macrophages for 1 hour, and analyzed by flow cytometry. (A) Representative histogram of macrophage intracellular fluorescence from one ITP patient before and after treatment. Platelets were labeled with the cell tracker CMFDA, opsonized with W6/32, and coincubated with macrophages at 37°C for 1 hour. Negative controls were performed at 4°C for 1 hour. The phagocytic index was calculated as the MFI obtained at 37°C divided by the MFI at 0°C. (B) Phagocytic capacity of macrophages from ITP patients before and after HD-DXM therapy and from healthy controls. *P < .05.