Clonal growth of functionally normal and deficient neutrophils from the bone marrow of a patient with variant chronic granulomatous disease : lack of reconstitution of oxidative burst defect by G-CSF, GM-CSF, and IFN-γ in vitro

To evaluate the effect of colony-stimulating factors and interferon gamma on the oxidative burst capacity of neutrophils in chronic granulomatous disease (CGD) we studied the neutrophils of a patient with variant CGD both from peripheral blood and from bone marrow culture on day 7 and 14. The results revealed that preincubation of peripheral neutrophils for 24 h in medium containing recombinant human granulocyte colony-stimulating factor (rhG-CSF), recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF), and recombinant human interferon gamma (rhIFN-gamma) alone or in combination did not improve the maximal oxidative burst activity measured by MTT assay. The colonies of this patient formed in agar assay were either composed of predominantly nitroblue tetrazolium (NBT)-positive cells or completely unable to reduce NBT. Despite variable colony numbers in the presence of different cytokines, the rate of NBT-positive colonies was less than 17% of the total number of colonies. However, more than 72% of the colonies were NBT positive in controls. In liquid culture, bone marrow cells yielded a comparable rate of NBT-positive and -negative populations at day 7. These data indicate that rhG-CSF, rhGM-CSF, and rhIFN-gamma alone or rhG-CSF and rhGM-CSF in combination with rhIFN-gamma are not able to reconstitute the oxidative burst defect in CGD in vitro. Indeed, regarding colony-forming capacity, the bone marrow cells from the patient responded to CSFs as well as those from control donors did. This fact may warrant the administration of hematopoietic growth factors, at least in variant CGD, in order to enhance the absolute number of functionally normal neutrophils.