Type I and Type II T Cell Profiles in Chronic Myelogenous Leukemia

T cell immunity is considered to play an important role in the control of cell growth in chronic myelogenous leukemia (CML) although information regarding the characteristics of T lymphocytes in CML patients is limited. Using flow cytometric analysis of intracellular cytokine expression at the single-cell level, we analyzed helper T and cytotoxic T subsets in 8 CML patients. The percentage of interferon-(gamma) (IFN-(gamma)) single-positive CD4 cells (Th1) and that of interleukin-4 (IL-4) singlepositive CD4 cells (Th2) was markedly decreased in pretreated CML patients compared to normal controls. In addition, the percentage of IFN-(gamma)/IL-4 double-positive CD4 cells (Th0) was also reduced. Consequently, the percentage of IFN-(gamma)/IL-4 double-negative CD4 cells was markedly increased. Similarly, a reduction in IFN(gamma) single-positive CD8 cells (Tc1) and IFN-(gamma)/IL-4 double-positive CD8 cells (Tc0) and an increase in IFN-(gamma)/IL-4 double-negative CD8 cells were observed in pretreated CML patients. Imbalance of these parameters was markedly improved following cytoreduction therapy. Our findings directly indicate anergic states in CML patients. Determination of the factors that affect Th and Tc profiles may lead to further understanding of immunological states and the development of effective immunotherapy.