Hemopoietic colony-forming cells in shwachman’s syndrome

Colony-forming capacities were studied in three Japanese children with Shwachman’s syndrome (chronic neu-tropenia and exocrine pancreatic insufficiency). Bone marrow granulocyte-macrophage colony-forming cells assayed in a soft agar culture were markedly reduced in all three cases. The cytochemical examination of granu-locyte-macrophage colonies by a new technique revealed that 90% of the colonies consisted exclusively of granu-locytes. Erythroid colony-forming cells assayed in a plasma clot culture were significantly reduced in two of the three cases. Bone marrow phagocytic cells did not suppress granulopoiesis in contrast to the cases of idio-pathic aplastic anemia. Moreover, the patient serum did not inhibit granulopoiesis of normal bone marrow cells. These results have been discussed with the possibility of involving the hemopoietic stem cells and other additional factors.