Doctors perform organ transplants as a last resort when a person has failure of their major organs such as the heart, lungs, liver or kidneys. Unfortunately, the patient's immune system tends to recognize the transplanted tissue as foreign and hence reject it . For years, scientists have eyed stem cells as the solution. They reasoned that if a patient's own stem cells were harvested and then coaxed into producing the necessary cell types the organ could be repaired and perhaps full organ transplant could be avoided. Since the patient could provide their own stem cells, availability is not a problem, and also the patient's immune system would accept the new tissue.
Did You Know?
A stem cell is a cell that has not yet committed to a specialized function in the body. These immature cells retain their ability to produce the other more specialized cell types in the body. How to coax these cells to become more "mature" and specialize is still an active area of research.
Recently, a research and surgical team in Spain reported that they have been able to help a young woman with a narrowed trachea. She had tuberculosis which caused narrowing of her trachea (major passageway for air into the lungs) and was having difficulty getting enough air to function in her day-to-day activities. As a result of the team's effort, they helped her regain full breathing ability by transplanting a trachea colonized by the patient's own stem cells. First, the researchers took a donated trachea and stripped it of all the live cells (which would have been rejected by the woman's immune system), leaving a shell or scaffold on which they seeded the patient's own stem cells.
Did You Know?
Like many organs or tissues the cells that line the trachea are held in place by a protein shell, or scaffold. These scaffolds control many properties of the cells that attach to them.
Next, the woman's stem cells attached to the scaffold and grew and divided to produce a new trachea. The surgical team then took the new tissue and transplanted it into the patient. Amazingly, the new trachea segment has been accepted by the woman's immune
system and after 4 months continues to function normally.
Did You Know?
Don't get caught up in the hype! Despite news reports suggesting that this breakthrough was made possible by stem cells, even the people who did the research admit that they were not entirely sure whether the stem cells they added before the transplant, or the patient's body cells after transplant, were the cells that made the graft work in the end.
Although this is an exciting breakthrough for stem cell research and transplant medicine, there remains much work to be done. Researchers still don't entirely understand why this transplant worked so successfully, and extending the positive results from the trachea transplant to other more complex organs or tissues will be much more difficult. But this work has certainly highlighted that what was once a distant dream, repairing our damaged bodies with stem cells, is quickly emerging as a reality.
An article from the BBC with an interesting video describing the transplant:
The Canada Stem Cell Network provides background information on stem cells and their future applications:
Read the profile of a Canadian stem cell researcher at The Hospital for Sick Children (SickKids) in Toronto:
Learn more about Stem Cells on our Stem Cells Theme Page!
Kevin Graham received a Ph.D in Medical Biophysics from the University of Western Ontario in 2007, and currently does stem cell research at the Hospital for Sick Children in Toronto. Although Kevin has great expectations for stem cell research, he has signed his organ donor card, just in case.
Article first published December 6, 2008
In a summary of an article published in The Lancet, Harvard Bioscience Inc. reports that, in a 5-year follow up to her 2008 trachea transplant, Claudia Castillo, is healthy and living a normal life. The article reports that her lung functions and immune responses are all normal. For more detail refer to the summary article at http://www.harvardbioscience.com/releasedetail.cfm?ReleaseID=799230 or the complete Lancet article at http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(13)62033-4/fulltext.
Update as of 05/05/2014 provided by Craig White