[Changes in NK cell activity in patients with acute leukemia]

Examination of the activity of NK-cells in peripheral mononuclear cells (PMNB) of patients with acute leukaemia (AL) was implemented before the onset of treatment and in the course of the disease following cytostatic treatment. The examination was made by the isotope method based on the release of 51Cr after 4-hour cultivation of effector cells with target cells of line K 562. The mean percentage of NK cellular activity in patients with AL was 9.9 and 5.9, as compared with normal values of 56 and 41 with ratios of effector and target cells of 40:1 and 20:1. The course of the disease after cytostatic treatment revealed that patients where complete remission occurred had before onset of treatment on average a higher NK-cell activity than those who responded poorly to treatment. In the majority of patients who were in complete remission the activity of NK-cells increased markedly.