Normothermic machine perfusion reduces epithelial injury and prolongs allograft preservation time compared to cold storage

Intestinal transplantation (IT) is the only treatment for patients with intestinal failure who cannot tolerate parenteral nutrition. However, IT often faces high rejection rates, partly due to damage from the currently practiced preservation method, static cold storage (CS). Furthermore, CS is limited to approximately 8 hour duration to enhance chances of success. Normothermic machine perfusion (NMP) preserves organs under physiological conditions, has improved outcomes in other transplants, and may benefit IT. This study aimed to evaluate the effects of NMP versus CS on reducing epithelial injury in porcine IT and to test the possibility of prolonging storage times via NMP. We hypothesized that NMP limits tissue damage, enhances epithelial recovery, and promotes graft stability for prolonged periods compared to CS. Small intestines from 18 Yorkshire-cross pigs were preserved using either CS (n=9) or NMP (n=9) and transplanted. In initial experiments, jejunal full-thickness biopsies were collected at intestinal procurement (T0), post-storage (T6), after 1-hour post-transplant reperfusion (T1RP), and 48 hours after transplantation (T48). In follow-up experimentation, the intestine was continuously perfused for increasing durations up to 12 hours. Histological injury was assessed using the Chiu-Park grade and, for those transplanted, a graft rejection scoring system including subepithelial bleb or Gruënhagen’s space formation, epithelial surface erosion/denuded villi, and columnar attenuation. Shotgun proteomics were employed to evaluate wound healing protein expression following NMP. NMP significantly reduced subepithelial bleb grade (NMP: 1.0 ± 0.7 vs. CS: 2.2 ± 0.4, p = 0.0125) at T1RP. Moreover, at T6, jejunal columnar attenuation grade was elevated (NMP: 1.4 +/- 1.342 vs. CS: 0 +/- 0, p = 0.0479), suggesting increased epithelial flattening and barrier restitution with NMP compared to CS. Compared to control tissue, CS incurred significantly higher Chiu/Park score, subepithelial bleb grade, and denuded villi grade at T1RP. In contrast, NMP preserved epithelial integrity up to 12 hours of storage (Chiu/Park 1.2 +/- 0.8367). Proteomic analyses revealed a 7-log2 fold increase in wound healing proteins such as Filamin A and Filamin binding LIM protein 1 in NMP-stored grafts (p < 0.05). NMP reduces epithelial injury and promotes recovery, in part through increased expression of filamin proteins, even following prolonged durations of storage. Increased durations of storage would significantly expand the pool of intestines available to patients in need. Overall, these findings demonstrate the potential of this novel allograft storage method to improve transplantation outcomes and thus the quality of life for many patients. U.S. Department of Defense PR181265; NIH K01OD010199 SERCA, NIH 5T32OD011130-15; 1R01Al182590-01 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.