Itk protein levels correlate with T-bet expression in aplastic anemia patients. (A) Cytoplasmic extracts from unstimulated T cells from patients with aplastic anemia (n = 12) and healthy controls (n = 3) were examined in immunoblot experiments for Itk expression. T cells from patients revealed increased Itk protein levels compared with healthy controls. The elevated Itk protein levels correlated with the increased T-bet protein levels observed in the same patients. Patient no. 11, a patient in remission, showed Itk protein levels comparable with healthy controls and did not express any T-bet in unstimulated T cells (data not shown). (B) Densitometric intensity of all the subjects studied is shown. The differences in Itk protein levels expressed in aplastic anemia patients and controls in unstimulated T cells were significant (P = .02). Horizontal lines represent mean values.