|
Stem Cell Transplantation; Findings in Stem Cell Transplantation Provide New Insights
Cancer Weekly
25 October 2005
2005 OCT 25 - (NewsRx.com) -- Reports from the United Kingdom, Spain and Japan highlight recent research on stem cell transplantation.
Study 1: Peripheral blood stem cells speed neutrophil/platelet engraftment in lymphoma patients.
"Lymphoma patients who require high dose chemotherapy are 'rescued' by reinfusion of stem cells to repopulate their bone marrow and minimize the risk of fatal infections or hemorrhage.
"This review evaluated the evidence for the use of stem cells derived from the peripheral blood to speed the engraftment of neutrophil and platelets when compared to standard bone marrow transplant," scientists in England wrote.
"A systematic search of the Cochrane Library, Medline, and Embase was carried out to identify randomized controlled trials comparing hematological recovery following these two interventions which met predetermined inclusion and exclusion criteria. Four studies were critically appraised and found to follow heterogeneous protocols but were otherwise of satisfactory quality.
"All four studies demonstrated an advantage of peripheral blood stem cell transplantation over bone marrow transplantation in terms of neutrophil recovery and three out of four demonstrated the same trend for platelet engraftment," said A. Lewis and colleagues at Darent Valley Hospital in Dartford.
"In sum," continued the authorsthere is evidence to support the use of peripheral blood stem cell transplantation for this population of lymphoma patients. Nurses can share this information confidently with patients and other staff."
"However, a more extensive review of studies which have investigated the association between extended neutrophil and platelet recovery and length of hospitalization, number of septic neutropenic episodes and cost reduction is needed to give a fuller picture of the effects for treatment," Lewis concluded.
Lewis and colleagues published their study in International Journal of Nursing Studies (Autologous stem cells derived from the peripheral blood compared to standard bone marrow transplant; time to engraftment: A systematic review. Int J Nurs Stud, 2005;42(5):589-596).
For additional information, contact A. Lewis, Darent Valley Hospital, Dartford & Gravesham NHS Trust Kent, Darenth Wood Rd., Dartford DA2 8DA, Kent, England.
Study 2: Umbilical cord blood is better than haploidentical mobilized peripheral blood for sustained engraftment.
According to recent research published in the journal Bone Marrow Transplantation, "We have reported short periods of post transplant neutropenia in human patients co-transplanted with cord blood (CB) and low numbers of haploidentical mobilized peripheral blood (MPB) CD34+ cells.
"To investigate the effect that the proportion of MPB to CB cells may have on engraftment kinetics, we have co-transplanted fixed numbers of human CB CD34+ cells mixed with different numbers of MPB CD34+ cells into NOD/SCID mice."
"We periodically quantified the proportion of human cells and the relative contribution of MPB and CB cells to the human engraftment on marrow aspirates.
"At the lowest MPB/CB ratios (5:1, 10:1), the contribution of CB cells predominated at all time points analyzed, and in three out of four experiments MPB cell contributions progressively decreased from day +15," reported M. Ramirez and colleagues at the University Autonoma, Madrid.
"At higher MPB/CB ratios," the authors continued, "MPB cells had a more important contribution to both early and late engraftment, with the highest cell ratio resulting in only marginal CB cell engraftment."
"Therefore, our results showed greater potential, on a per cell basis, of human CB vs. MPB cells for competitive sustained engraftment in the xenogeneic model used, which was only abrogated by the co-infusion of very high numbers of MPB cells," Ramirez concluded.
Ramirez and colleagues published their study in Bone Marrow Transplantation (Engraftment kinetics of human CD34+cells from cord blood and mobilized peripheral blood cotransplanted into NOD/SCID mice. Bone Marrow Transplant, 2005;35(3):271-275).
For additional information, contact M.N. Fernandez, University Autonoma Madrid, Hospital University Clinical Puerta Hierro, Service Hematology & Hemoterapia, C San Martin de Porres 4, Madrid 28035, Spain.
Study 3: Surrogate markers and agents for peripheral blood stem cells mobilization improve collection efficiency.
"Factors affecting collection efficiency of peripheral blood stem cells (PBSCs) include patient's age, diagnosis, preceding chemoradiotherapy, disease invasion of the bone marrow and mobilizing chemotherapy in PBSC collection for autologous transplants.
"Mobilizing cytokines, timing for apheresis, machines and operating software would affect mobilization and collection of PBSCs both for autologous and allogeneic transplantation. Also donor's age and gender would affect PBSC yield for allogeneic transplantation," investigators in Japan report.
"Surrogate markers including peripheral blood CD34+ cell counts before mobilization and on day of collection have been reported to predict the yield of PBSC harvest," wrote K. Ikeda and coworkers.
The authors concluded, "A number of standard procedures have been developed based on these findings. Newer agents for PBSC mobilization are being evaluated and still other factors affecting mobilization are being sought to better predict and cope with poor mobilization."
Ikeda and colleagues published their study in Transfusion and Apheresis Science (Factors for PBPC collection efficiency and collection predictors. Transfus Apher Sci, 2004;31(3):245-259).
For additional information, contact K. Ikeda, Okayama University, School of Medicine, Division Blood Transfusion, 2-5-1 Shikata Cho, Okayama 7008558, Japan.
The information in this article comes under the major subject areas of Stem Cell Mobilization, Surrogate Markers, Cell Yield and Allogeneic Stem Cell Transplantation.
This article was prepared by Cancer Weekly editors from staff and other reports. Copyright 2005, Cancer Weekly via NewsRx.com.
|
