Positive selection of CD34+ peripheral blood progenitor cells in patients with low-grade lymphoid malignancies and bone marrow involvement.

Purpose: 16 patients with low-grade lymphoid malignancies and bone marrow involvement were transplanted with selected CD34 positive Peripheral Blood Progenitor Cell (PBSC) prepared from autologous aphereses.

Patient and methods: All but one patients were mobilized with a combination of chemotherapy (including high-dose cyclophosphamide and VP16 or adriamycin, aracytin with cysplatyl) and recombinant human Granulocyte Colony-Stimulating Factor (rhG-CSF).

Results: A median of 3 (range, 1 to 9) aphereses yielded 15.35 x 10(6) CD34+ cells/kg (range, 4.45 to 70.88). A median of 5.01 x 10(6) adsorbed CD34+ cells/kg (range 2.01 to 24.13) was obtained after selection (median purity: 86%; range, 59-99%). The CD34 PBSC were infused one day after either one of two conditioning regimens: 11 patients received the association of cyclophosphamide (120 mg/kg) and TBI (8Gy), and 5 patients received the BEAM regimen. No recombinant hematopoietic growth factor was used after cell reinfusion. Median days to 0.5 x 10(9)/l neutrophils and 50 x 10(9)/l platelets were 13 (range, 9 to 18) and 16 (range, 11 to 35), respectively. The median number of red blood cell (RBC) unit transfusions was 4 (range, 0 to 10). The median number of platelet transfusions was 3.5 (range, 0 to 8). No individual received backup PBSC, nor required platelet transfusion beyond 3 months post-transplant.

Conclusion: This study confirms the feasability of using blood CD34 cells to support hematopoietic recovery after myelo-suppressive or myelo-ablative regimens, in patients with low-grade NHL.