Agranulocytosis: a report of 30 cases.

Thirty cases of acute agranulocytosis, as defined by Schultz, were observed between 1946 and 1964 at the Hôtel-Dieu Hospital, Montreal. In 14 cases agents incriminated were: aminopyrine, phenylbutazone, sulfonamides and chlorpromazine. Aminopyrine alone was responsible for eight cases. In the remaining 16 cases no definite etiology was established. Clinical manifestations included fever, prostration, angina and multiple pharyngeal ulcerations; these were associated with severe leukopenia and agranulocytosis. The bone marrow showed hypoplasia, lymphocytosis and maturation arrest. Localized and pulmonary infections, pseudomembranous enterocolitis and septicemia were frequent complications in 21 cases and were usually responsible for death, which occurred in 12 cases. Almost all patients who developed septicemia or pseudomembranous enterocolitis died. The pathogenesis is still not clear, but chlorpromazine and its analogues may act as a metabolic inhibitor, while the aminopyrine group probably operates through an immune mechanism.