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agranulocytosis(əgrăn'yəlōsītō`sis), disease in which the production of granulated white blood cells by the bone marrow is impaired. Although the disease may occur spontaneously it is usually induced by exposure to antithyroid drugs, sulfonamides, phenothiazines, chemotherapy, and radiation therapies. Granulocytes protect the body against infectious agents; their depletion results in severe respiratory infections, ulceration of the mouth and colon, high fever, and prostration. These symptoms may occur suddenly or over a period of days or weeks. Penicillin is usually the drug of choice to combat the bacterial invasion. Treatment may require bone marrow transplants to start the production of healthy white blood cells. The fatality rate is high (approaching 80%) in untreated cases, and deaths are common even with antibiotic treatment.
(also, agranulocytic angina), the absence or drastic reduction of granulocytes in the blood. Agranulocytosis may develop during various infectious diseases, avitaminoses, and diseases of the hematic system and as a result of the direct action of chemicals (benzene), drugs (aminopyrine, sulfanilamides, antibiotics, and others), and ionizing radiation on the bone marrow. Sometimes agranulocytosis results from an allergic reaction and the formation of autoantibodies against the leukocytes. Acute agranulocytosis is characterized by general indisposition, fever, and ulcerations of the skin and mucous membranes, especially of the oral and pharyngeal cavities. The number of neutrophils in the blood diminishes. Recurrent agranulocytosis is most often connected with repeated ingestion of certain drugs or repeated contact with certain chemicals; periods of aggravation and improvement alternate during its course. Treatment includes elimination of the causes; blood transfusions; administration of vitamins of the B group (B2, B6, B12), hormonal preparations (corticotrophic hormones), and antibiotics; and topical treatment of the ulcerative processes. In especially severe cases, treatment calls for transplanting bone marrow. Prophylaxis involves the isolation of the causative agent and elimination of contact with it.