Naive and memory phenotyp13.6pe distribution in CD8⁺ and CD4⁺ T cells from patients with LGL leukemia compared with healthy control subjects using coexpression patterns of CD45RA and CD62L. (A) Flow cytometry was performed on cells stained with CD3, CD8, CD62L, and CD45RA. A gate was set on CD3⁺ cells and a second gate set on CD8⁺ (R3) and CD8⁻ (CD4⁺⁾ T cells. CD62L (x-axis) and CD45RA (y- axis) were used to distinguish specific T-cell subsets that included naive (top right quadrant), central memory (bottom right quadrant), effector memory (bottom left quadrant), and terminal-effector memory (top left quadrant) T cells. Representative results from healthy donors aged 30 and 57 years and a patient with LGL leukemia aged 57 years are shown. (B) Graphic representation of the mean percentage positive of these 4 distinct T-cell subsets in patients with LGL leukemia (n = 6) compared with age-matched healthy control subjects (n = 6). Standard deviation (SD) is indicated, and statistical significance was determined by a Wilcoxon sum rank test.