Diverse clinical applications using advantages of allogeneic peripheral blood stem cell transplantation

A Comparison of Fresenius Com.Tec Cell and Spectra Optia Cell Separators for Autologous and Allogeneic Stem Cell Collections: Single Center Experience

Peripheral blood is the prefered source for hematopoietic stem cells for hematopoietic stem cell transplantation. The efficiency of peripheral blood stem cell (PBSC) collection can vary among devices. In this study we aimed to compare feasibility and effectivity of apheresis procedures of the different systems. Two apheresis systems [Com.Tec (Fresenius Healthcare) and Spectra Optia (Caridian BCT)] were used in our center for the collection of PBSCs for autologous and allogeneic transplantation. We retrospectively analysed 190 apheresis procedures performed in healthy donors and patients between June 2012 and November 2014 in Department of Hematology, Dokuz Eylul University. PBSCS were collected by Fresenius cell separator (64 procedure) or Spectra Optia cell separator (126 procedure). Mobilization treatments were G-CSF (26.8%), cyclophosphamide plus G-CSF (48.4%), prelixafor plus G-CSF (14.7%), ESHAP (10%) and others. Patient and donor characteristics (age, weight, volume processed, disease, mobilization regimes) were similar in Fresenius and Spectra Optia apheresis groups. Altough both collected PBSCs efficiently, the amount of CD34+ cell in product collected by Spectra Optia device was significantly higher (p < 0.05) and product volume was lower than Fresenius Com.Tec significantly (p < 0.05). "CD34+ collection efficiency" with Spectra Optia was significantly higher than Fresenius Com.Tec (CE2: 87%, 70%, p = 0.033) regarding all procedures. High collection efficiency and low product volume may be a significant characteristic of Spectra Optia device (mean 187 mL, product CD34+ cell: 1576 µL).

The human-sheep chimeras as a model for human stem cell mobilization and evaluation of hematopoietic grafts' potential

OBJECTIVE

To investigate whether the sheep xenograft model of human hematopoiesis can be used to mimic mobilization of human hematopoietic stem cells in vivo.

MATERIAL AND METHODS

Sheep transplanted with 3.6 x 10(6) CD34+ from human adult bone marrow were mobilized 1.5 years posttransplantation with human granulocyte colony-stimulating factor for 5 days. At day 3 and 4 of mobilization, human cells were harvested from peripheral blood (PB) and bone marrow (BM) and were injected into secondary sheep recipients (n = 6) and these animals were analyzed for the presence of human cells in their BM and PB, starting at 3.5 months posttransplantation.

RESULTS

Maximum mobilization of human cells in PB occurred at day 3, with a 21-fold increase in total numbers of human cells, and a recovery of 5.5 x 10(4)/mL CD34+. In the BM, maximal numbers of human cells were achieved at day 4, with a 6.3-fold increase and a recovery of 1.5 x 10(4)/mL CD34+ cells. PB and BM mobilized human cells were then transplanted into new sheep recipients, and analysis at 3.5 months posttransplantation demonstrated that levels of human cell engraftment in BM of the group transplanted with mobilized PB were significantly lower than those transplanted with BM cells (0.6% +/- 0.1% vs 8.0% +/- 1.8%). Furthermore, in sheep transplanted with mobilized PB, the levels of human cells in circulation remained 2.5-fold higher than the levels of human cells found in their BM.

CONCLUSION

Mobilization of human cells in the sheep model parallels human PB and BM hematopoietic stem cells (HSC) mobilization in healthy human donors in their ability to engraft, differentiate, and repopulate secondary hosts. Thus, this model can become a useful tool to study mobilization regimens, mechanisms, and quality of products obtained.

Tailored strategy for AML patients receiving allogeneic peripheral blood stem cell transplantation

Considering the heterogeneity of acute myelogenous leukemia (AML), along with the pros and cons of allogeneic peripheral blood stem cell transplantation (PBSCT), a tailored strategy is needed to minimize the transplant-related mortality and maximize the transplant outcomes in AML patients exhibiting certain factors that have an impact on the post-transplant quality of life and outcomes. The factors that need to be considered when tailoring a strategy in an allogeneic PBSCT setting include the recipient's performance status and co-morbid disease include AML risk stratification, disease status, expected severity of graft-versus-host disease, and the necessity of a graft-versus-leukemia effect. Accordingly, this review article describes a possible tailoring strategy for AML patients receiving allogeneic PBSCT based on certain factors influencing the transplant outcome.

Clinical impact of a new automated system employed for peripheral blood stem cell collection

At the moment, PBSC collections can be performed using semi-automated or automated cell separator devices. The automated methods offer the advantages of a decreased working load for dedicated personnel and high standardization of the collection procedure. Herein we report our single institutional experience in 80 PBSC collections employing the new automated COM.TEC Fresenius autoMNC program that provides the ability to predict the total number of CD34(+) cells collected, based on the pre-leukapheresis CD34(+) cell count in peripheral blood. Fourty-eight patients and 21 healthy donors were mobilized with chemotherapy + G-CSF or G-CSF alone, respectively. Eighty leukapheresis collections were performed starting with a CD34(+) cell count in peripheral blood at least of 20/microL. Collection parameters and related side effects were evaluated. The mean CD34(+) cell collection efficiency in patients and donors was 81.8% (sd 27.6) and 95.1% (sd 15.6), respectively. The mean difference between real and predicted CD34(+) cells was +30.2% (sd 92.9) for patients and +4.6% (sd 30.3) for donors. The mean leukapheresis bag volume was 240.7 ml (sd 67.3) and 310.3 ml (sd 86.8) with a mean HCT of 10.9% (sd 34.4) and 9.2% (sd 3.9) for patients and donors, respectively. The automated PBSC collection with the new program COM.TEC Fresenius autoMNC demonstrated a very high CD34(+) cell collection efficiency. Moreover, the ability to predict the CD34(+) cell yield permits improved management of the leukapheresis collection, with the only disadvantage of larger leukapheresis volume and higher hematocrit.