Studies in acute leukemia. II. Chemotaxis of leukemic blasts from patients with acute nonlymphoid leukemia: its relationship with IgG Fc receptors and role of surface-bound immunoglobulin.

Leukemic blasts from patients with acute myeloblastic and acute monocytic leukemia were studied for their chemotaxis towards casein- or endotoxin-activated serum as well as for the presence of Fc receptors and surface immunoglobulins. Leukemic blasts from patients with acute myeloblastic leukemia lacked both Fc receptors and surface immunoglobulin and did not migrate towards chemoattractants. Leukemic blasts from patients with acute monocytic leukemia, however, demonstrated heterogeneity with regard to Fc receptors, surface immunoglobulins and chemotaxis, and could be divided into three groups: in group I, leukemic blasts which lacked both Fc receptors and surface immunoglobulin moved poorly; in group II, large proportions of leukemic blasts and Fc receptors but lacked surface immunoglobulins. These blasts migrated well towards the chemoattractants, and in group III, leukemic blasts which had both Fc receptors and surface immunoglobulins lacked chemotactic property. A correlation between the presence or absence of Fc receptors and chemotaxis was observed. In group III, lack of blast cell migration appears to be due to passive binding of IgG via the Fc receptors.