Susceptibility of acute myelogenous leukemia blasts to lysis by lymphokine-activated killer (LAK) cells and its clinical relevance

To help understanding host-tumor relationships in acute myelogenous leukemia (AML) and better define indications for interleukin 2 (IL-2) therapy in this disease, we studied the relationship between the susceptibility of leukemic cells of 44 AML patients to lysis by autologous (26 cases) and/or allogeneic (41 cases) lymphokine-activated killer (LAK) cells and characteristics of the leukemia. Lymphocytes were activated in the presence of 1000 u/ml recombinant IL-2 for 5 days. Lysis of AML cells was studied by 51 Cr release. Average lysis of AML cells by autologous LAK cells was 9 ± 13% and by allogeneic LAK cells 10 ± 9% with a significant correlation between lyses by both effectors ( p = 0.01). Autologous ( p = 0.005) and allogeneic ( p = 0.004) lyses were higher in patients with initial infection. Allogeneic lysis was correlated with initial WBC count ( p = 0.009), serum lactic-dehydrogenase level ( p = 0.05), and expression of CD13 ( p = 0.01). Autologous lysis was inversely correlated with expression of CD34 ( p = 0.003). Expression of adhesion molecules CD54 (ICAM-1) and CD58 (LFA-3) by the leukemic cells did not correlate with their lysis by LAK cells. Susceptibility of leukemic cells to lysis by LAK cells did not correlate with prognosis of the leukemia.