Impaired NK cells and increased T regulatory cell numbers during cytotoxic maintenance therapy in AML

• We studied immunomodulatory effects of cyclic cytotoxic maintenance therapy in AML.
• Patients in CR had low NK, TH and Treg counts and a reduced NK activation capacity.
• After maintenance therapy, NK counts declined, while TH and Treg cells increased.
• The proliferative potential of TH cells was reduced after maintenance therapy.
• Immunotherapeutic approaches in post-remission have to consider these impairments.

Cyclic cytotoxic maintenance therapy can be applied to patients with AML in post-remission. We studied the immune status of AML patients in complete remission and the effect of maintenance therapy on different immune cell populations. Patients in complete remission had reduced NK, TH and Treg counts and a reduced NK activation capacity. In the course of cytotoxic maintenance therapy, NK counts further declined, while TH and Treg cells increased, with lower proliferative potential of TH cells. We conclude that immunotherapeutic approaches in post-remission have to consider reduced NK cell function and further impairment of cellular immune responses during cytotoxic therapy.