[LAK cells and cancer]

The effectiveness of LAK cells (lymphokine-activated killer cells) on malignant tumors in vivo and in vitro was discussed. LAK cells induced from lymphocytes by interleukin-2 (IL-2) were able to kill target malignant cells in a nonspecific manner. Combination of IL-2 enhanced LAK activity. Adoptive immunotherapy with LAK cells and IL-2 carried out in the USA has produced effective results in several cases; complete regression of skin metastases of malignant melanoma and partial regression of other malignancies. However, high doses of IL-2 mediated a toxic side effect, capillary permeability leak syndrome. Our studies have revealed that LAK cells after one to two weeks incubation do not require such a high concentration of IL-2, and that adoptive immunotherapy using such, LAK cells and IL-2 can be carried out safely.