CD34 Positive Cells Mobilized with Chemotherapy Plus Recombinant Human Growth Hormone (rhGH) and Recombinant Human Granulocyte Colony-Stimulating Factor (rhG-CSF) Allows Sustained Engraftment in Previously Non-Mobilizer Patients.

The availability of adequate amounts of peripheral blood progenitor cells (PBPC) is a prerequisite for the feasibility of high-dose therapy program in patients with neoplastic diseases. Due to prior chemio-radiotherapy or disease related factors, 20–30% of patients fails to mobilize sufficient amounts of PBPC. Therefore, non-mobilizer patients cannot complete their therapeutic program. The aims of the present study were: 1) to evaluate the combination rhGH+rhG-CSF after chemiotherapy as a mobilization regimen in previously non-mobilizers patients; 2) to assess safety and tolerability of rhGH+rhG-CSF treatment; 3) to evaluate hematopoietic recovery after reinfusion of rhGH+rhG-CSF mobilized PBPC. After informed consent, three patients (2 male, 1 female), that failed a previous mobilization cycle, were remobilized with chemotherapy plus rhGH (100μg/Kg/d, sc) and rhG-CSG (5μg/Kg/d, sc).

No specific side effects were noticed due to rhGH treatment. Reinfusionof PBPC after myeloablative therapy resulted in hematopoietic recovery with 16, 9, 11 days respectively to reach an absolute neutrophil count ≥ 500/μl and 24, 15, 15 days respectively to reach a platelet count ≥ 50000/μl. Hematopoietic engraftment is complete and sustained with a follow-up of 18, 11 and 9 months, respectively.

In conclusion our data confirm that the addition of rhGH to rhG-CSF allows mobilization and collection of PBPC in previously non-mobilizer patients, and therefore the programmed high-dose therapy program can be satisfactorily completed, with sustained hematopoietic recovery.