DURABILITY OF HEMATOPOIESIS FOLLOWING AUTOGRAFTING WITH PERIPHERAL-BLOOD HEMATOPOIETIC PROGENITORS

Background: It is still. not known whether hematopoiesis reconstituted by autografting with the peripheral blood hematopoietic progenitors ( CPCs) after myeloablative high dose radiotherapy and/or chemotherapy i s durable and capable of coping with the increased demand imposed by b oost radiotherapy, surgery, or infection. Patients and methods: The du rability of hematopoiesis was evaluated in 34 consecutive cancer patie nts treated with myeloablative total body irradiation (n = 17, median followup 3 years, range 3-49 months) and/or alkylating-agent chemother apy (n = 17, median follow-up 8 months, range 6-41 months) and autogra fted with CPCs because bone marrow autografting was contraindicated. C PCs (greater than or equal to 8x10(6) CD34+ cells/kg) had been collect ed during mobilization into the circulation in response to previous an ticancer therapy and hematopoietic growth factor(s). Results: Followin g brief temporary pancytopenia, all patients achieved normal and durab le hematopoiesis. The newly reconstituted hematopoietic system was cap able of reacting favorably to stressful and debilitating events such a s surgery, radiotherapy, or varicella-zoster infection. No secondary i rreversible failure of blood cell production occurred. Conclusions: Th e documentation of the durability of normal hematopoiesis following my eloablative cancer therapy and autografting with mobilized CPCs implie s that the latter procedure, rather than being solely an alternative t o bone marrow autografting, represents an advantageous tool of choice permitting substantial amelioration of the therapeutic index of high-d ose cancer therapy.