Peripheral blood-derived stem cell collections for use in autologous transplantation after high dose chemotherapy: an alternative approach.

Peripheral blood-derived hematopoietic stem cells (PBHSC) can be utilized to reconstitute hematopoiesis in patients after high dose myeloablative chemotherapy. We have performed PBHSC reinfusion in 18 patients who have or had a history of tumor involving the bone marrow or a hypocellular bone marrow. The PBHSC were collected by continuous flow leukapheresis and subsequently cryopreserved. A median of 31.9 X 10(9) (range 18 X 10(9)-67.2 X 10(9)) mononuclear cells or a median of 4.85 X 10(8) mononuclear cells/kg (range 2.7 X 10(8)-11.0 X 10(8)) were collected. Fifteen patients had in vitro assays of granulocyte-monocyte colony-forming cells (CFU-GM) performed with a median of 2.7 X 10(4) (range 0-11.5 X 10(4)) CFU-GM/kg. To date, of the 18 patients collected, all have undergone high dose chemotherapy and PBHSC reinfusion. For the evaluable patients, granulocyte recovery (greater than 500 X 10(6)/ml) has occurred in a median of 15 days and platelet recovery (greater than 50 X 10(9)/ml without transfusion support) has occurred in a median of 43 days. Four patients have had prolonged thrombocytopenia and still require platelet transfusion at 80+, 97+, 124+, and 270+ days. PBHSC collection is safe and effective for hematopoietic reconstitution after high dose chemotherapy in the majority of patients; however incomplete hematopoietic reconstitution has been observed in 4/18 evaluable patients. This procedure requires further investigation.