Flow cytometric assessment of leukocyte function in sickle cell anemia.

Sickle cell anemia is associated with susceptibility to infection due to hyposplenism and the reduced ability of neutrophils to kill pathogenic organisms. In this study, blood samples from sickle cell anemia patients were divided into two groups: the painful crisis group and the steady state group. Flow cytometric assessment of phagocytosis and burst formation of neutrophils and monocytes as well as basophil function were performed, and these were compared to those of age- and sex-matched normal control subjects. Neutrophils and monocytes in sickle cell anemia patients were significantly different from those in the normal control subjects in the areas of weaker phagocytosis, fewer ingested bacteria and reduced burst formation. Basophil degranulation was normal. This pilot study using flow cytometry explains in part the susceptibility to infection of sickle cell anemia patients despite their high neutrophil and monocyte counts.