Adult stem cell transplants are helping thousands of patients every year. Of the over 50,000 adult stem cell transplants per year, a little less than half use donor ("allogeneic") adult stem cells, from bone marrow or umbilical cord blood. In those cases, it is critical that a proper match be made. Without a good match, the transplanted donor cells may fail to engraft, or worse, may attack their new host, a condition called "graft versus host disease" (GVHD).

Now scientists at the University of Texas Southwestern Medical Center have shown that growing blood-forming adult stem cells in the lab for about a week can overcome much of the problem of immune rejection for these transplants. They developed a recipe for growth of both mouse and human adult stem cells in culture, greatly expanding the numbers of cells available for transplant. They also found that the lab-grown adult stem cells started to produce a specific immune system inhibitor, CD274, on their cell membranes and this also improved transplant efficiency. Overall, they achieved a 40-fold increase in transplantation ability, using mice as a model. They hope to be able to achieve as least as good a result for human adult stem cells.

According to senior author Dr. Cheng Cheng Zhang:

"If donor human [adult stem cells] can be expanded in culture and engraft non-matched or low-matched patients without graft-versus-host disease, this strategy will possibly lead to an ultimate solution to problems in allogeneic transplantation."

In other words, a short period of growth in the lab could mean no more problems in matching for donor adult stem cell transplants.

The research is published in the journal Cell Stem Cell.