Impact of stem cell source on allogeneic stem cell transplantation outcome in hematological malignancies.

BACKGROUND/AIM: Peripheral blood (PB) is used more frequently as a source of stem cells (SCs) for allogeneic transplantation. However, the influence of cell source on the clinical outcome of SC transplantation is not yet well established. The aim of this study was to compare the results of PBSC transplantation (PBSCT) with bone marrow transplantation (BMT) on the basis of engraftment, frequency and severity of immediate (mucositis, acute Graft versus Host Disease--aGvHD) and delayed (chronic GvHD--cGvHD) complications, as well as transplant-related mortality (TRM), transfusion needs, relapses and overall survival (OS). METHODS: We analyzed 158 patients, women/men ratio 64/94 median age 29 (range 9-57), who underwent allogeneic SC transplantation between 1989 and 2009. All included patients had diseases as follows: acute myeloid leukemia (AML)--39, acute lymphoblastic leukemia (ALL) 47, chronic myeloid leukemia (CML)--32, myelodysplastic syndrome (MDS)--10, Hodgkin's lymphoma (HL)- 2, multiple myeloma (MM) 3, granulocytic sarcoma (GrSa) 3, severe aplastic anemia (sAA)--22. The patients underwent transplantations were divided into two groups: BMT group (74 patients) and PBSCT group (84 patients). Each recipient had HLA identical sibling donor. SCs from bone marrow were collected by multiple aspirations of iliac bone and from PB by one "Large Volume Leukapheresis" (after recombinant human granulocyte colony stimulating factor, rHuG-CSF) application (5-12 microg/kgbm, 5 days). Conditioning regimens were applied according to primary disease, GvHD prophylaxis consisted of combination of a cyclosporine A and methotrexate. Results. Engraftment, according to the count of polymorphonuclear and platelets, were significantly (p < 0.001) faster in the PBSCT vs BMT group. The needs for transfusion support were significantly (P < 0.01) higher in the BMT group. Those patients had more frequently oropharingeal mucositis grade 3/4 (33.3% vs 10.0%, p < 0.05). There were no significant differences in the incidence of aGvHD and cGvHD between the two groups. The patients who underwent PBSCT had more frequently extensive cGvHD in comparison with the BMT group (29.1% vs 11.29%, p < 0.05). SC source (SCS) had no significant influence on the TRM (21.62% vs 23.8%, p = 0.64) and the incidence of relapses (21.6% vs 29.7%, p = 0.32). Finally, the patients treated by BMT hd a significantly better OS (logrank 2.33, p < 0.05). Conclusion. SCs harvesting from PB resulted in improved cell yield, faster engraftment, as well as in a decrease of immediate transplantation related complications with a reduced treatment cost. Allogeneic PBSCT were associated with more frequent extensive cGvHD, while the influence of SCS in TRM and relapses was not observed. Finally, the long-term OS was better in the patients treated by BMT. To verify impact of SC source on transplantation (PBSCT vs BMT) overall efficacy, more larger randomized clinical studies are needed.

Stem cell harvesting protocol research in autologous transplantation setting: large volume vs. conventional cytapheresis.

BACKGROUND/AIM: The use of peripheral blood as a source of hematopoietic stem cells (SCs) is progressively increasing and has nearly supplanted bone marrow transplantation. Interpatient variability in the degree and kinetics of SC mobilization into peripheral blood is an expected event after conventional chemotherapy-based treatment, followed by sequential administration of recombinant granulocyte-colony-stimulating factor (rHu-CSF). In this study, specific factors associated with the application of two different SC-harvesting approaches, including the use of large volume leukapheresis (LVL) vs. repetitive conventional apheresis (RCA), were analyzed. The basic goal of the study was to evaluate the influence of apheresis protocol (collection timing, processed blood volume and cell yield) upon the clinical outcome of transplantation. METHODS: Results obtained by LVL (76 pts) and RCA (20 pts--control group) were compared. The SC mobilizing regimen used was cyclophosphamide (4-7 g/m2) or polychemotherapy and rHuG-CSF 10-16 microg/kg of body mess (bm) per day. Cell harvesting was performed using Caridian-BCT Spectra (Gambro, USA). The volume of processed blood in LVL setting was > or = 3.5-fold of the patient's circulating blood quantity (ranged from 12.7 to 37.8 l). All patients tolerated well the use of intensive treatment, without any side or adverse effects. Our original controlled-rate cryopreservation was carried out with 10% dimethyl sulfoxide (DMSO) using Planer R203/200R or Planer 560-16 equipments (Planer Products Ltd, UK). Total nucleated cell (NC) and mononuclear cell (MNC) counts were examined by flow cytometry (Advia-2120 Bayer, Germany; Technicon H-3 System, USA). The CD34+ cell surface antigen was investigated by the EPICS XL-MCL device (Coulter, Germany). RESULTS: Performing LVL-apheresis, high-level MNC and CD34+ cell yields (7.6 +/- 4.6 x 10(8)/kg bm and 11.8 +/- 6.5 x 10(6)/kg bm, respectively) were obtained. As a result, rapid hematopoietic reconstitution ("graft-healing")--on the 9.4th and 12.4th day for granulocytes and platelets, respectively was achieved. Using repetitive conventional apheresis (2-3 procedures), the total MNC count was high (8.2 +/- 7.0 x 10(8)/kg bm), but the total CD34+ yield was lower 10.8 +/- 9.9 due to inferior CD34+ vs. MNC ratio. CONCLUSION: The results obtained suggest that well-timed LVL-apheresis increased SC-yield in cell harvest, resulting in faster bone marrow repopulation and hematological reconstitution, as well as better overall clinical outcome of transplantation. These results necessitate additional examinations of CD34+ subsets ratio in cell harvest.