Increased T-bet levels in T cells from patients with aplastic anemia. (A) Cytoplasmic and nuclear extracts from healthy volunteers were analyzed in immunoblots for T-bet expression. T-bet could be detected only in the nucleus of normal T cells after at least 18 hours of stimulation with PMA and ionomycin. STAT1 served as a control to show differences in cytoplasmic-nuclear localization. Actin was used to show equal loading of the samples. (B) Unstimulated nuclear extracts from healthy volunteers and aplastic anemia patients were analyzed for T-bet expression. All patients' samples were run side-by-side with healthy donors' samples. Patients had significantly increased levels of T-bet compared with controls. (C) Densitometric intensity of immunoblots results from all the subjects studied. The results obtained from unstimulated T-cell T-bet expression between healthy individuals and aplastic anemia patients were highly significant (P < .001). Horizontal lines indicate mean values.