Drug-induced agranulocytosis: evidence for the commitment of bone marrow haematopoiesis.

Clinical and haematological features of 61 patients with drug-induced agranulocytosis (63 episodes) are presented. Multiple drug consumption was a common observation and complicated the attempt to incriminate a particular drug as being aetiologically involved. Bone marrow analysis shortly after the diagnosis revealed evidence for an impairment of proliferative granulopoiesis in the majority of cases. This observation was confirmed by in vitro culturing of granuloid precursor cells (CFU-c). Moreover, the data clearly demonstrated that drug-induced agranulocytosis may not be restricted to the granulocytic series. Thrombocytosis and reticulocytosis during the recovery phase are taken as an indication for the commitment of all haemopoietic cell lineages in agranulocytosis. These observations were in accordance with cytomorphological studies and in vitro culture data of erythroid precursor cells (CFU-e, BFU-e) of bone marrow aspirates taken in the initial phase of agranulocytosis. More than 25% of the patients showed a marked erythroid depression in the marrow.