RESUMEN
PURPOSE: Serum levels of G-CSF and GM-CSF were measured and CFU-GM assay using G- CSF, GM-CSF and SCF was conducted to evaluate the influence of hematopoietic growth factor on the precursor cells of cyclic neutropenia. METHODS: A 7-year-old male with cyclic neutropenia was studied. Marrow mononuclear cells were isolated at neutrophil nadir and recovery and cultured in methylcellulose media with or without G-CSF, GM- CSF and SCF. CD34 positive cells were evaluated using flow cytometry. Serum levels of G-CSF and GM-CSF were measured by ELISA. RESULTS: The Numbers of CFU-GM without growth factors were 50 at neutrophil nadir and 33 at the recovery phase in the patient and show increased colony forming capacity. CD34 positive cells were 9.32% at nadir and 14.17% at recovery. Increasement of CFU-GM with G-CSF at nadir and recovery were 46% and 118% and those with GM-CSF were 70% and 78% respectively, compared with 54.4% and 78.2% in control groups. In contrast, the presence of SCF did not enhance CFU-GM number in the patient, but in the control group, increasement with SCF was 28.9 %. There an was inverse relationship between serum G-CSF levels and peripheral neutrophil count whereas those of GM-CSF were constant. CONCLUSION: Serum G-CSF level showed inverse relationship with neutrophil counts. The response of progenitor cells to G-CSF and GM-CSF was not impaired. The presence of SCF did not enhance CFU-GM number in the patient. This result suggests that the abnormality in hematopoiesis in cyclic neutropenia may involve more immature progenitor cells responsive to SCF.