Significant increase in the percentage of peripheral CD45RA⁺ CD8⁺ T cells in thymoma patients.

Three-color FACS-based analyses of CD8, CD4, and CD45RA expression by PBL, gated on CD3⁺ T cells. Error bars depict the SE. Controls, ■; patients, ░. (A) Bars indicate the mean percentage of CD8⁺ or CD4⁺ cells among circulating CD45RA⁺ T cells in patients with thymic follicular hyperplasia (TFH; n = 7), thymoma patients (Tm; n = 15), and corresponding control groups. The CD8⁺ subset in thymoma patients is significantly increased when compared with controls (P = .002), whereas the percentage of circulating CD45RA⁺CD8⁺ cells does not differ significantly between MG patients with TFH and controls (P = .8). In contrast, there is no significant difference in the percentage of CD45RA⁺CD4⁺ T cells between either of the 2 patient groups and their respective controls (TFH: P = .6, Tm: P = .8). (B) The difference between the percentage (means indicated by bars) of circulating CD45RA⁺CD8⁺ T cells in patients with thymoma and normal controls is more significant when thymoma is not associated with MG (Tm/MG−) (n = 6) (P = .01) than when it is (Tm/MG+) (n = 9) (P = .05).