Natural cytotoxicity in adult acute leukemia

Natural cytotoxic activity was studied in 32 adult patients with acute non-lymphoid leukemia (ANLL) and 27 adult patients with acute lymphoblastic leukemia (ALL). Thirteen patients with active ANLL had a significantly reduced natural cytotoxicity in peripheral blood compared with that of healthy controls, 5.0 +/- 3.4 versus 27.1 +/- 11.5 (p less than 0.0005). Patients with ANLL in remission had a normal natural cytotoxicity (p greater than 0.05). Patients with active ANLL had a significantly reduced number of Leu-7-positive cells (p less than 0.001), while patients in remission had normal proportions of these cells (p greater than 0.05). Peripheral blood from patients with ALL showed reduced natural killer (NK) cell activity, both in active disease and in remission (p less than 0.0005). The percentage of Leu-11b (CD 16)-positive cells was increased in patients in remission from ALL (p less than 0.05). Bone marrow cells from patients with ALL in remission had a reduced natural cytotoxicity, 2.8 +/- 4.0 versus 16.3 +/- 9.0 in bone marrow controls (p = 0.01). In contrast, patients with ANLL in remission showed a normal bone marrow cytotoxicity (p greater than 0.05) while patients with active ANLL had a reduced NK cell activity (p less than 0.03). The low NK activity observed in leukemic patients may be of importance for the pathogenesis of the diseases. Acute non-lymphoid leukemia (ANLL) is a malignant disease of the multipotential hemapoietic stem cell. The stem cell is capable of differentiating into various cell lineages, i.e. erythroid, granulocytic, monocytic and megacariocytic cell lineages.(ABSTRACT TRUNCATED AT 250 WORDS)