Abstract
Granulopoiesis was studied in five children with congenital neutropenia.
Marhinal granulocyte pool and bone marrow granulocyte reserve were reduced in all patients. Leukocytes mobilization to inflammatory sites was also reduced.
Assay of granulocyte-macrophage colony forming cells in a double agar culture system demonstrated normal CFU-C numbers in four patients but reduced in one patient with Shwachman's syndrome (chronic neutropenia and exocrine pancreatic insufficiency). In one patient with normal CFU-C number, colonies consisted exclusively of macrophages. In another patients, colonies were indistinguishable from normal colonies morphologically.
Production of colony stimulating factor (CSF) from patients' peripheral blood leukocytes appeared normal when tested on normal marrow.
No serum inhibitors against CFU-C could be demonstrated.
By in vitro culture, three patterns of congenital neutropenia emerged:
In type 1, in vitro parameters were normal.
In type 2, commited stem cell showed reduced number.
In type 3, defective commited stem cell differentiation along the granulocyte cell line was presumed.
We conclude that etiology of congenital neutropenia is heterogeneous.
