Lithium therapy of children with chronic neutropenia.

We treated five children with chronic neutropenia using lithium carbonate and studied the effect in vivo on granulopoiesis. Granulocyte precursors (CFU-C) from blood and marrow, and colony-stimulating activity (CSA) from peripheral blood leukocytes, were assayed in a methylcellulose tissue culture system. Three patterns of response to lithium were seen. In patients with aplastic anemia (one acquired and two Fanconi's aplastic anemia) despite increased colony-stimulating activity, CFU-C numbers remained very low and the neutropenia persisted. In a patient with Kostmann neutropenia colony-stimulating activity, and blood and marrow CFU-C numbers increased, but the agranulocytosis was unchanged. An impressive therapeutic effect was seen in one patient with idiopathic neutropenia with low colony-stimulating activity who responded to lithium with an increase in colony-stimulating activity and CFU-C resulting in persisting normal neutrophil counts. Lithium appears useful in treating a select group of neutropenic patients in whom colony-stimulating activity production is responsive to lithium, and the granulocytic progenitor compartment is capable of producing mature neutrophils.