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Cord Blood; Researchers from the United States, Iran and Japan Report Details of New Studies and Findings in the Area of Cord Blood
Medical Devices & Surgical Technology Week
30 May 2006
2006 MAY 30 - (NewsRx.com) -- Cord blood data are the focus of recent research from the United States, Iran and Japan.
Study 1: Umbilical cord blood cell expansion is improved following bone marrow-derived mesenchymal stem cell co-culture.
According to recent research from the United States, "One factor limiting the therapeutic efficacy of cord blood (CB) hematopoietic progenitor cell (HPC) transplantation is the low cell dose of the graft. This is associated with an increased incidence of delayed or failed engraftment."
"Cell dose can be increased and the efficacy of CB transplantation potentially improved, by ex vivo CB expansion before transplantation. Two ex vivo CB expansion techniques were compared: (1) CD133+ selection followed by ex vivo liquid culture and (2) co-culture of unmanipulated CB with bone-marrow-derived mesenchymal stem cells (MSCs)," researchers said.
"Ex vivo culture was performed in medium supplemented with granulocyte colony-stimulating factor, stem cell factor and either thrombopoietin or megakaryocyte growth and differentiation factor.
"Expansion was followed by measuring total nucleated cell (TNC), CD133+ and CD34+ cell, colony-forming unit and cobblestone area-forming cell output," wrote S.N. Robinson and colleagues at M.D. Anderson Cancer Center in Houston.
The authors reported, "When compared to liquid culture, CB-MSC co-culture (1) required less cell manipulation resulting in less initial HPC loss and (2) markedly improved TNC and HPC output."
"CB-MSC co-culture therefore holds promise for improving engraftment kinetics in CB transplant recipients," suggested Robinson.
Robinson and colleagues published their study in Bone Marrow Transplantation (Superior ex vivo cord blood expansion following co-culture with bone marrow-derived mesenchymal stem cells. Bone Marrow Transplant, 2006;37(4):359-366).
For additional information, contact S.N. Robinson, University of Texas, MD Anderson Cancer Center, Dept. Blood & Marrow Transplantation, 1515 Holcombe Blvd., Unit 65, Houston, TX 77030, USA.
Study 2: Cryopreservation does not impair the clonogenic capacity and in vitro expansion potential of umbilical cord blood stem cells.
"Umbilical cord blood progenitor cells have been demonstrated to possess significant advantages over bone marrow in terms of proliferative capacity and immunologic reactivity.
"But the low number of hematopoietic stem cells (HSC) is the most important limitation of its use," scientists writing in the journal Transplantation Proceedings report.
According to the authors, "The ex vivo expansion of cord blood progenitor cells is the current strategy to overcome this problem. Furthermore, among the factors that enable successful cord blood transplantation is the ability to store and subsequently recover a sufficient number of viable cells.
"Since it would be costly to expand umbilical cord blood (UCB) progenitor cells, it is important to determine the feasibility and reproducibility of progenitor cell expansion after cryopreservation."
"We evaluated whether cryopreservation procedures might impair the clonogenic capacity and in vitro expansion of UCB.
"We evaluated the cell viability, clonogenic capacity, CD34+38- content and in vitro expansion potential of progenitor cells from UCB (n=10) separated mononuclear cells (MNC), before and after 1 month of cryopreservation by programmed rate freezing," wrote L. Moezzi and colleagues at the University of Teheran..
"Although cell viability decreased after cryopreservation (p<0.05)," continued researchers, "there was no significant difference in CD34+ or CD34+38- absolute count, clonogenic capacity and in vitro expansion potential of cord blood progenitor cells (p>0.05).
"Since the survival of CD34+ cells was greater than other elements, CD34+ cells seem more tolerant to cryopreservation than the other nucleated populations. Moreover in vitro expansion of UCB progenitor cells may be obtained following cryopreservation."
Moezzi concluded, "Our results suggest that cryopreservation procedures do not impair the clonogenic capacity and in vitro expansion potential of cord blood stem/progenitor cells."
Moezzi and colleagues published their study in Transplantation Proceedings (The effect of cryopreservation on clonogenic capacity and in vitro expansion potential of umbilical cord blood progenitor cells. Transplant Proc, 2005;37(10):4500-4503).
Additional information can be obtained by contacting L. Moezzi, University of Teheran, Iranian Blood Transfusion Org, Hemat High Way, Tehran 4686, Iran.
Study 3: Umbilical cord blood transplantation cures severe chronic active Epstein-Barr virus infection after double failure of hematopoietic stem cell transplantation.
According to a study from Japan, "An 11-year-old boy with severe chronic active Epstein-Barr virus infection (CAEBV) underwent successful cord blood transplantation (CBT) after consecutive failure of peripheral blood and bone marrow transplantation from his HILA-mismatched mother.
"CB cells from an unrelated donor were infused after conditioning with total body irradiation (12 Gy), melphalan (120 mg/m2), and etoposide (600 mg/m2). Complete remission without circulating EBV-DNA has continued for 15 months after a delayed hematologic recovery."
"This is the first successful report of CBT for CAEBV," wrote M. Ishimura and colleagues at Kyushu University in Fukuoka.
The authors concluded, "CB may, therefore, be an alternate source of stem cells for the curative treatment of CAEBV, despite the absence of EBV-specific cytotoxic T lymphocytes."
Ishimura and colleagues published the results of their research in American Journal of Hematology (Successful umbilical cord blood transplantation for severe chronic active Epstein-Barr virus infection after the double failure of hematopoietic stem cell transplantation. Am J Hematol, 2005;80(3):207-212).
For additional information, contact S. Ohga, Kyushu University, Graduate School of Medicine Science, Dept. Pediatrics, 3-1-1 Maidashi, Fukuoka 8128582, Japan.
Keywords: Fukuoka, Japan, Chronic Active Epstein-Barr Virus Infection, Umbilical Cord Blood Transplantation, Failed Stem Cell Transplantation, Curative Treatment.
This article was prepared by Medical Devices & Surgical Technology Week editors from staff and other reports. Copyright 2006, Medical Devices & Surgical Technology Week via NewsRx.com.
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