Optimal timing of G-CSF administration after CD34(+) immunoselected peripheral blood progenitor cell transplantation

G-CSF accelerates neutrophil recovery after autologous peripheral blood pro genitor cell transplantation (aPBPCT), although the optimal timing for its administration is currently unknown. In order to establish the role and the optimal timing of administration of G-CSF after immunoselected CD34(+) aPB PCT, we analyzed the data from 21 consecutive patients affected by haematol ogical malignancies. Patients were randomized into three groups according t o G-CSF administration after transplantation: day +1 (group B); day +7 (gro up C) or no G-CSF (group A). Serum G-CSF level was evaluated until engraftm ent, The CD34+ cell dose reinfused was similar (P = 0.48), G-CSF significan tly reduced time to recovery of PMN >0.5 x 10(9)/l (11 vs 14 vs 20.5 days) (P = 0.00046); >1.0 x 10(9)/l (12 vs 15 vs 22) (P = 0.001), No difference w as observed in the number of days with PMN <0.1 x 10(9)/l (5.5 vs 7 vs 8 da ys), Platelet count >50 x 10(9)/l and >100 x 10(9)/l, reticulocytes >1%, le ngth of hospitalization, non-prophylactic antibiotic therapy, fever, incide nce of sepsis and transfusion support did not differ, Early or delayed G-CS F after immunoselected CD34(+) aPBPCT significantly accelerated PMN recover y but did not reduce the amount of supportive treatment or the duration of hospitalization. Delaying the initiation of G-CSF did not reduce the length of treatment (11.5 vs 12 days). Early or delayed G-CSF administration resu lted in G-CSF peak serum levels 7 (early)-12 (delayed)-fold greater than an endogenous response to neutropenia.