Bioengineering: Restoring damaged human lungs via cross-circulation to a pig

Damaged human lungs that have been rejected for organ transplantation could be reconditioned through the use of cross-circulation from a pig, suggests a paper published in Nature Medicine.

The availability of lung transplantation—the only definitive cure for end-stage lung disease—remains limited due to an insufficient supply of high-quality donor lungs. Current strategies for increasing the availability of donor lungs include the use of ex vivo lung perfusion (EVLP), a technique that continuously pumps oxygen and nutrients to support the function of donor lungs outside the body before transplantation, but it remains unclear how well EVLP can rehabilitate damaged lungs.

In previous work, Gordana Vunjak-Novakovic, Matthew Bacchetta and colleagues found that damaged pig lungs could be reconditioned when connected to the circulation system of another pig. In this paper, the same researchers explored whether the same process could be used to recondition human lungs. The authors connected five damaged human lungs, which had previously been rejected for transplantation, to the circulatory system of a pig. The pigs were treated with immunosuppressive drugs to prevent rejection of the lungs. After 24 hours of connection, the histology and function of the damaged human lungs had improved, including one lung that had been declined for transplantation after EVLP. The authors propose that lungs rejected for transplantation, which cannot be recovered through the use of EVLP, could be reconditioned by this cross-circulation approach.

The authors note that future studies will be needed to assess the clinical potential of this approach, including accounting for the possibility that residual pig cells and factors in the lungs could cause immune responses in or disease transmission to the transplant recipient.