Acquired agranulocytosis is a rare, drug-induced blood disorder that is characterized by a severe reduction in the number of white blood cells (granulocytes) in the circulating blood. The name granulocyte refers to grain-like bodies within the cell. Granulocytes include basophils, eosinophils, and neutrophils.
Acquired agranulocytosis may be caused by a variety of drugs. However, among the drugs to which a patient may be sensitive are several used in the treatment of cancer (cancer chemotherapeutic agents) and others used as antipsychotic medications (e.g., clozapine). The symptoms of this disorder come about as the result of interference in the production of granulocytes in the bone marrow.
People with acquired agranulocytosis are susceptible to a variety of bacterial infections, usually caused by otherwise benign bacteria found in the body. Not infrequently, painful ulcers also develop in mucous membranes that line the mouth and/or the gastrointestinal tract.