The use of CD 34(+) mobilized peripheral blood as a donor cell source does not improve chimerism after in utero hematopoietic stem cell transplantation in non-human primates.

In utero hematopoietic stem cell transplantation is a therapeutic procedure that could potentially cure many developmental diseases affecting the immune and hematopoietic systems. In most clinical and experimental settings of fetal hematopoietic transplantation the level of donor cell engraftment has been low, suggesting that even in the fetus there are significant barriers to donor cell engraftment. In postnatal hematopoietic transplantation donor cells obtained from mobilized peripheral blood engraft more rapidly than cells derived from marrow. We tested the hypothesis that use of donor hematopoietic/stem cells obtained from mobilized peripheral blood would improve engraftment and the level of chimerism after in utero transplantation in non-human primates. Despite the potential competitive advantage from the use of CD 34(+) from mobilized peripheral blood, the level of chimerism was not appreciably different from a group of animals receiving marrow-derived CD 34(+) donor cells. Based on these results, it is unlikely that this single change in cell source will influence the clinical outcome of fetal hematopoietic transplantation.