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Nonobese diabetic‐severe combined immunodeficient mice transplantation of volume‐reduced and thawed umbilical cord blood transplants following closed‐system immunomagnetic cell selection
Author(s) -
Eichler Hermann,
Beck Christian,
Schröder Bernd,
Nguyen Xuan Duc,
Klüter Harald
Publication year - 2002
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1046/j.1537-2995.2002.00223.x
Subject(s) - transplantation , andrology , cd34 , immunomagnetic separation , umbilical cord , buffy coat , cord blood , progenitor cell , cd19 , immunology , stem cell , biology , medicine , flow cytometry , microbiology and biotechnology
BACKGROUND : Protocols for the expansion of human umbilical cord blood (UCB) progenitors begin with the selection of CD34+ cells from stored frozen and thawed units. Use of an immunomagnetic selection procedure within a closed blood bag system for volume‐reduced UCB transplants was evaluated, and the influence of CD34 cell selection on in vivo engraftment potential was studied. STUDY DESIGN AND METHODS: Eleven thawed buffy coat‐processed UCB units were processed within a standard blood bag with a washing solution. In six independent experiments, the same dosage of 2 × 104 CD34+ cells from paired selected and nonselected samples was transplanted into NOD‐SCID mice. In two experiments, cells from the negative fraction were also transplanted. RESULTS : The purity of CD34+ cells after selection was correlated with the removal of supernatant after the first washing step and therefore with adequate removal of damaged or dead cells (r = 0.86, p < 0.01). Mice transplanted with unselected UCB cells had more human cells within their marrow than animals transplanted with selected cells (8.6 ± 5.9% selected group vs. 19.8 ± 14.2% unselected group; p = 0.04), whereas no engraftment could be observed transplanting cells from the two negative fractions. A higher percentage of human CD45+ cells in the unselected group were found to be positive for CD38, CD14, CD33, and CD19, indicating a higher potential for these unselected progenitors to differentiate into myeloid cells and B cells. CONCLUSIONS : Processing of volume‐reduced and thawed UCB transplants within a closed‐bag system before immunomagnetic CD34+ cell selection allows for the preparation of CD34+ cells of significant purity at technically useful cell recoveries. However, these experiments indicate a potential impairment of engraftment capacity for the CD34+ cell‐enriched fraction.