Felty's syndrome. Effect of lithium on granulopoiesis

The effect of lithium carbonate upon granulopoiesis was studied in eight patients with Felty's syndrome. Absolute granulocyte counts increased in all patients receiving 900 mg lithium carbonate daily for six weeks. Increased urinary and serum granulocyte colony-stimulating activity was observed in all patients during lithium therapy. A casual relationship between increases in colony-stimulating activity and increased granulocytes is postulated.