TEMRA cells without features of exhaustion are expanded in patients with ITP and correlate with disease activity. (A) Peripheral CD4⁺:CD8⁺ ratio is significantly lower in patients with ITP than in controls, indicating CD8-mediated disease. (B) A t-distributed stochastic neighbor embedding (tSNE) plot of the T-cell CD4⁺ and CD8⁺ subsets based on their surface expression of CD45RA and CD62L in a control patient and a patient with ITP. Expanded TEMRA cells from a patient with ITP are shown. (C) An example of a dot plot from flow cytometry analysis of a control vs a patient with ITP, using CD45RA and CD62L. (D) Patients with ITP compared with controls have significantly higher numbers of TEMRA cells. (E) Patients with platelet counts <30 × 10⁹/L have higher numbers of TEMRA cells than those with platelet counts ≥30 × 10⁹/L. (F) An example of a dot plot from flow cytometry analysis of a control vs a patient with ITP, showing expression of IFN-γ and TNFα. (G) CD8⁺ T cells in patients with ITP have increased IFN-γ, TNFα, and granzyme B; polyfunctional CD8⁺ T cells (expressing IFN-γ, TNFα, and granzyme B) are also increased in patients with ITP. (H) PD-1 expression has not changed, and Tim-3 expression is reduced in TEMRA cells. ∗P ≤ .05; ∗∗P ≤ .01; ∗∗∗P ≤ .001.