[Acute agranulocytosis induced by pyramidon or phenothiazines. Apropos of 31 cases].

The authors present 31 cases of acute agranulocytosis due to drugs. 27 resulted from amidopyrine poisoning and 4 were due to phenothiazines. The clinical picture in most cases, was that of severe septicemia with lesions of the mucosae. On blood count agranulocytosis was complete, associated on bone marrow examination with an appearance of selective hypoplasia of the granular series or an aspect of maturation blockage at the stage of the myelocyte or the metamyelocyte. The course was fatal in 6 cases. A search for leukocyte agglutinating antibodies, carried out in 29 cases, was positive in only 5 cases. These facts correspond, on the whole, to the, clinical and etiological data found in the literature. Although the agranulocytoses induced by phenothiazines, seem to be mainly of toxic origin, the agranulocytoses induced by amidopyrine associated both an immunological mechanism and a toxic mechanism. Among all the biological tests proposed, the most useful is the le ukocyte agglutination test, but the serological diagnosis is rarely conclusive.