Current Status of Leukemia Cytotherapy - Exploitation with Immune Cells

With the development of chemotherapy and hematopoietic stem cell transplantation (HSCT), the prognosis of leukemia patients has been improved greatly in the past few decades. However, relapsed and refractory leukemia is still the major cause of mortality in leukemia patients. Besides, advancing age, poor performance status and severe co-morbidities limit the applicability of cytotoxic chemotherapy in certain groups of leukemia patients. Novel agents including nucleoside analogs, kinase inhibitors targeting oncoproteins and monoclonal antibodies are under investigation for the management of leukemia. Nevertheless, the outcome remains disappointing. Since immune system plays an important role in eradicating tumor cells, a lot of studies have been conducted in the administration of cytotherapy of immune cells as an alternative method when chemotherapy and transplantation fail to cure the disease, including usage of natural killer (NK) cells, cytokine-induced killer (CIK) cells, donor lymphocyte infusion (DLI), chimeric antigen receptor (CAR)-modified T cells, dendritic cell (DC)-based vaccine and antigen-specific cytotoxic T lymphocytes (CTL). Due to overexpression of several leukemia associated antigens (LAA), leukemic cells are potentially suitable for cellular therapy approach. Here we review the recent literature regarding the different types of cytotherapy against leukemia, and talk about both efficacy and adverse effects related to the strategy.