Functional evaluation of circulating leukemic cells in acute non-lymphocytic leukemia

Abstract

Peripheral blood leukemic cells from 32 patients with acute non-lymphocytic eukemia (ANLL) were tested in vitro for their ability to adhere to nylon fibers and to phagocytize latex particles and S. aureus. In vivo migration to skin windows was also assessed. Using heparinized whole blood, leukemic cells from 47% of patients ( 9 19 ) adhered to fibers although the percent adherence was decreased compared to the per cent of granulocyte adherence in these patients. Phagocytosis by leukemic cells of S. aureus and latex was seen in 44% ( 12 77 ) of patients studied and migration to skin windows occurred in 44% ( 10 23 ). Only cells from patients with some degree of monocytic differentia-(monocytic or myelomonocytic leukemia) were functional while blasts from patients with myelocytic, promyelocytic or poorly differentiated leukemia were non-functional. Prominent extramedullarly leukemic involvement was more common in patients with functional monoblasts and on occasion dominated the patient's clinical course. These data indicate that some degree of monocytic functional maturation takes place in many patients with ANLL and may account for the increase in extramedullary infiltration seen in patients with monocytic leukemia. The simple functional tests described may supplement morphologic criteria in the characterization of ANLL.