Impaired marrow granulocyte reserve and leukocyte mobilization in leukemic reticuloendotheliosis.

Cytotoxic chemotherapy often induces sustained, severe granulocytopenia in patients with leukemic reticuloendotheliosis. Many of the patients so treated subsequently develop serious infections. Poor marrow reserve has been implicated but lacks supporting evidence as the cause of the granulocytopenia. In six patients we studied with leukemic reticuloendotheliosis, bone marrow showed severe granulocytopenia, blood neutrophil response after intravenous hydrocortisone injection was poor, and leukocyte migration to the site of inflammation showed suboptimal neutrophilia and poor or no mononuclear response. Splenic hypersequestration and pooling were probably not important factors in causing neutropenia, since similar results were seen in patients without spleens. These findings suggest that in this disease the marrow granulocyte reserve and leukocyte mobilization are impaired and the neutropenia is due to poor granulocyte production and not to increased migration of leukocytes to tissues. Cytotoxic chemotherapy should be used with caution in patients with this disease.