Bone marrow colony-forming cells in acute drug-induced agranulocytosis.

The capacity to differentiate and form colonies in vitro by bone marrow granulocytic precursor cells and its evolution were studied in eight cases of drug-induced acute agranulocytosis. In three cases colonies and clusters count were normal or high. These cases were probably immunological agranulocytosis. In the five other cases this number was very low and returned to normal from three to thirteen days. These were probably cases of marrow suppression by the drug.