Emphysema and cystic fibrosis patients who need new lungs are faced with a life-threatening problem: more than 80 percent of donated lungs can’t be used—they’re inflamed and barely functional [Scientific American]. Transplanted lungs also fail at a much higher rate than other transplanted organs, as they’re more likely to be rejected by the recipient’s body. But a new procedure that makes use of gene therapy may soon double or triple the supply of undamaged donated lungs, and may also improve their function once transplanted.
In both pre- and post-transplant lungs, the problem is inflammation caused by insufficient amounts of an immune molecule called IL-10. Donated lungs are immediately chilled on ice, which destroys any IL-10 that may remain in the lungs, allowing substantial damage to occur before the organ can be implanted. And a lack of the molecule after transplantation increases the likelihood that inflammation will damage the organ and induce rejection [Los Angeles Times].
To get around these problems, the researchers first built a domed chamber where pig lungs were kept at body temperature with a steady flow of oxygen and nutrients moving through them. That arrangement alone prevented substantial damage to the lungs. Next, in the gene therapy stage, the researchers used a harmless virus to bring a gene that produces IL-10 into the lung cells.
Lead researcher Shaf Keshavjee explains that the lungs that received the therapy had better blood flow and were more able to take in oxygen and expel carbon dioxide, the study showed. “It’s as if gene therapy turbocharges each individual cell to manufacture many more proteins in its own IL-10 factory,” Keshavjee said [Bloomberg]. The lungs also performed better and were better tolerated by the pigs who received the transplants, according to the study published in Science Translational Medicine.
The researchers also tried the first parts of the procedure on donated human lungs that were too damaged to transplant. The human lungs showed the same improvements in blood flow and respiration, suggesting that the therapy could repair lungs that would otherwise have been discarded, and could therefore increase the stock of available organs. Last year, 234 people in the U.S. died while waiting for a lung transplant…. Currently, more than 1,800 people in the U.S. are waiting for a lung [Bloomberg].
The human lungs weren’t transplanted into sick patients, but if Keshavjee’s experiments continue to go well human trials could begin in about a year. While questions about gene therapy remain–in some cases, the viral vectors used to transport genes have been found to cause serious side effects–the new approach has the potential to be a breath of fresh air.
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DISCOVER: The Second Coming of Gene Therapy
Image: Science / AAAS
November 2nd, 2009 at 4:21 pm
Even if there is side effects, the benefits defidently outweigh the negatives. I think if a person on their deathbed had a choice between death and possible complications, then they would take the risk.
November 4th, 2009 at 11:01 pm
I agree. A patient with no options, facing hours to days of life left, would most likely pick complications than assured death if given the choice.
November 6th, 2009 at 12:13 am
Well I’ll tell you what your assumption would be correct with me. But you must wonder why so many people who should recieve lung transplants decide that they dont want to deal with it in any way. well because 50% of lung transplant recipeints die anyways. Now if this could help increase the chances of survival I can guarantee that people like me who will one day innevitably be on that donor list will be more willing to choose life over death with lighter amount of complications. Also note that anybody under the age of 18 who recieves a transplant has about a .02% chance of living for 1 whole year after recieving the donation. Can you imagine how much hope parents could have if this increased the chances of survivability for Children. my hat goes off to this doctors discovery if it really does help with these things. I have Cystic Fibrosis I would like my chances to be better in the long run.