Researchers Grow Human Lungs in Lab

OK, they didn’t “grow” lungs – they took parts from two sets of lungs, assembled them, and caused the lung cells to replicate until the whole structure was functional.  Still, pretty impressive.

Lungs are a notoriously delicate organ. That makes useable donor lungs hard to come by—in 2010, just 1,800 lung transplants took place in the United States. However, researchers are getting closer to addressing the shortage by growing lungs, for the first time, in the lab. Although these lungs haven’t been actually transplanted, the technology could someday help shorten the list of people waiting for donors.

…In the past, washing a donor organ of its cells could take up to four months to accomplish, but the latest study introduced a device that sped that process up to three days. The resulting lungs are eggshell white, because of the lack of blood flowing in the new organ.

…it will take at least 10 years before they are ready for people in need of a transplant.

Source: Scientists Grow First Functioning Human Lungs

The proof of concept used portions of lungs from deceased children – cadaveric donation is nothing new.  Next step is testing in pigs…

This is actually hope for cystic fibrosis (CF) patients. CF patients get on a waiting list for a maximum of two lung transplants (regardless of if their bodies reject the lungs or not) in their lifetimes, beginning when their pulmonary function tests reach a certain percent of normal lung capacity. The average life expectancy of CF patients is 37 years, but lungs that match their DNA and reduce risk of rejection show promise for greatly increasing this life expectancy.

How is this better than a regular lung transplant?

Besides the lack of viable donor organs, the main issue with transplants today is chronic rejection. If you receive a lung transplant, you’re put on immunosuppressants to stop your immune system from attacking those donor lungs, yet in the long run it usually does just that anyhow. The immune system begins to attack the donor lungs and eventually they’re so damaged that most lung transplant patients end up needing another transplant after a few years.  The life expectancy of lung transplant recipients is 6 years on average before dying either from chronic rejection or one of the side effects of immunosuppression (cancer, opportunistic infections, kidney/liver failure).

With the technique described, rejection and in turn the need for immunosuppression (and all associated negative consequences of being immunocompromised) might be avoided entirely. Doctors could one day take the lung of a deceased donor, reduce it to only the scaffolding, then “rebuild” the lung itself using material from the prospective recipient.  The result would be lungs that are as good as new and genetically identical to the recipient’s own lungs – thus invisible to the recipients’ immune system.

This is an important step towards growing solid organs from scratch. Right now they need to strip down a real lung, but one day it might be possible to 3d-print such a structure without requiring a donor organ. This would solve the organ shortage, eliminating the organ donation waiting lists.  But then the bottleneck will be hospital beds and staff…