Phenotypic changes in neutrophil granulocytes of healthy donors after G-CSF administration.

BACKGROUND AND OBJECTIVE The aim of the present work was to analyze the immunophenotypic changes in neutrophil granulocytes (NG) and their evolution over time in 16 healthy donors who received G-CSF for stem cell mobilization for allogeneic peripheral blood stem cells (PBSC) transplantation. DESIGN AND METHODS The mobilization schedule consisted of G-CSF (Filgrastimq, Amgen) 10 microg/kg, s.c. for five consecutive days. Apheresis began 16-24h after the last dose of G-CSF. Immunophenotypic analysis (CD10, CD14, CD15, CD16, CD71, CD34 and HLA-DR) of NG and measurement of G-CSF serum levels were performed before G-CSF administration (day 0), on the fifth day of G-CSF treatment and days +7 and +30 after the last dose of G-CSF. RESULTS After G-CSF administration, peripheral blood NG presented increased expression of HLA-DR, CD34, CD14, and CD71, in addition to decreased expression of CD10 and CD15 and CD16 fluorescence mean intensity. The phenotypic changes on NG were parallel to serum G-CSF levels. All the phenotypic changes returned to the baseline values by one month after the end of G-CSF treatment. No changes were found in the expression of HLA-DR on T and B-lymphocytes. INTERPRETATION AND CONCLUSIONS These immunophenotypic changes suggest that after G-CSF administration NG from healthy donors who received G-CSF for stem cell mobilization carry transient features of immature phenotype and have increased functional activity.