CD47 is overexpressed on Sézary cells and correlates with worse OS. (A) Representative fluorescence-activated cell sorter (FACS) plots of gating strategy identifying CD47 expression on Sézary cells (with a dominant Vβ13.2⁺ T-cell population) in comparison with nonmalignant T cells (CD4⁺Vβ13.2⁻) in a patient with SS. CD47 expression was determined on Sézary cells (red histogram) compared with nonmalignant CD4⁺ cells (blue histogram) and isotype control (green histogram). (B) The MFI of CD47 on CD4⁺Vβ⁺ (Sézary cells, red) and matched CD4⁺Vβ⁻ (nonmalignant lymphocytes, blue) cells in patients with SS (n = 25). Two-tailed unpaired Student t test (****P < .0001). (C) Representative immunohistochemistry (IHC) samples of the skin biopsy from a patient with SS with low CD47 expression (left panel) and 1 with high CD47 expression (right panel) (anti-CD47 with red chromagen stain; original magnification ×40). The level of expression of CD47 on Sézary cells in the peripheral blood determined by flow cytometry provided on the right of the corresponding skin biopsy. (D) Kaplan-Meier curves of OS (months) of patients with SS having a low CD47 expression on Sézary cells (<6537 MFI) vs high CD47 expression (>6537 MFI) on Sézary cells (n = 25). Log-rank (Mantel-Cox) test (P < .001). FITC-A, fluorescein isothiocyanate area; FSC-A, forward scatter area; PE-A, phycoerythrin area; SSC-A, side scatter area.