Objective

To investigate the association between the T cell inhibitory receptor programmed death 1 (PD-1) and T cell exhaustion status in T cells from patients with de novo acute myeloid leukemia (AML) and AML in complete remission (CR).

Methods

Surface expression of PD-1 and the exhaustion and immunosenescence markers CD244 and CD57 on CD3+, CD4+ and CD8+ T cells from peripheral blood samples from 20 newly diagnosed, untreated AML patients and 10 cases with AML in CR was analyzed by flow cytometry. Twenty-three healthy individuals served as control.

Results

A significantly higher percentage of PD-1+ cells were found for CD3+ T cells in the de novo AML group compared with healthy controls. In addition, an increased level of PD-1+ CD8+ T cells, but not PD-1+ CD4+, was found for CD3+ T cells in the de novo AML and AML-CR samples. A higher percentage of CD244+ CD4+, CD244+ CD8+, CD57+ CD4+ and CD57+ CD8+ T cells was found in CD3+ T cells in samples from those with de novo AML compared with those from healthy controls. Strong increased PD-1+ CD244+ and PD-1+ CD57+ co-expression was found for CD4+ and CD8+ T cells in the de novo AML group compared with healthy controls.

Conclusions

We characterized the major T cell defects, including co-expression of PD-1 and CD244, CD57-exhausted T cells in patients with de novo AML, and found a particular influence on CD8+ T cells, suggesting a poor anti-leukemia immune response in these patients.