A cell-free nutrient-supplemented perfusate allows four-day ex vivo metabolic preservation of human kidneys.

The growing disparity between the demand for transplants and the available donor supply, coupled with an aging donor population and increasing prevalence of chronic diseases, highlights the urgent need for the development of platforms enabling reconditioning, repair, and regeneration of deceased donor organs. This necessitates the ability to preserve metabolically active kidneys ex vivo for days. However, current kidney normothermic machine perfusion (NMP) approaches allow metabolic preservation only for hours. Here we show that human kidneys discarded for transplantation can be preserved in a metabolically active state up to 4 days when perfused with a cell-free perfusate supplemented with TCA cycle intermediates at subnormothermia (25 °C). Using spatially resolved isotope tracing we demonstrate preserved metabolic fluxes in the kidney microenvironment up to Day 4 of perfusion. Beyond Day 4, significant changes were observed in renal cell populations through spatial lipidomics, and increases in injury markers such as LDH, NGAL and oxidized lipids. Finally, we demonstrate that perfused kidneys maintain functional parameters up to Day 4. Collectively, these findings provide evidence that this approach enables metabolic and functional preservation of human kidneys over multiple days, establishing a solid foundation for future clinical investigations.

Reanimating Pancreatic Grafts Subjected to Prolonged Cold Ischemic Injury Using Normothermic Ex Vivo Perfusion.

Background: Pancreas transplant volumes are limited because of poor utilization of "extended criteria grafts." Prolonged cold ischemia is a risk factor associated with poor allograft survival. We aimed to establish the feasibility of transplantation using grafts subjected to prolonged cold ischemia and determine whether these grafts could be optimized using normothermic ex vivo perfusion (NEVP) in a porcine model. Methods: The study population consisted of 35 to 40 kg male Yorkshire pigs in an allotransplantation model with a 3-d survival plan for recipients. Control grafts were subjected to cold storage (CS) in a University of Wisconsin solution for 21 to 24 h (n = 6), whereas the test group received an additional 3 h NEVP after CS of 21 h (n = 5). Results: The 3-d survival was 60% in the NEVP arm versus 0% in the control arm (P = 0.008; log rank). Graft parenchyma was 60% to 70% preserved in the NEVP arm at necropsy on gross appearance. In addition, the islet function was well preserved, and both the pancreas (including the islets) and the duodenal morphology were maintained histologically. The intravenous glucose tolerance test on the day of euthanasia was in the normoglycemic range for 80% of cases in the NEVP arm. Conclusions: Optimization of pancreas grafts exposed to extended CS with NEVP seems promising at rescuing and reanimating these grafts for transplantation, resulting in significantly improved survival in a porcine pancreas transplant model.

Increasing Age Hinders the Decline in B-Type Natriuretic Peptide Following Parathyroidectomy in Dialysis Patients.

BACKGROUND/AIM: Parathyroidectomy has beneficial effects on all-cause and cardiovascular mortality in patients with uncontrolled hyperparathyroidism. B-Type natriuretic peptide (BNP) correlates with the severity of heart failure. We aimed to investigate whether parathyroidectomy modulates the BNP levels in dialysis patients. PATIENTS AND METHODS: Patients who underwent surgical intervention for hyperparathyroidism were included. The serum BNP levels were determined before parathyroidectomy and during follow-up. RESULTS: The preoperative and postoperative BNP levels were 499±561 and 453±442 pg/ml, respectively (p=0.82). The baseline BNP level was positively correlated with weakness and headache, but not biochemical parameters. In multivariate analysis, age (odds ratio=0.837) and preoperative symptom score (odds ratio=0.935) were independent predictors for the postoperative decline in BNP levels Conclusion: The serum BNP levels may increase or decrease after parathyroidectomy. Younger age and lower symptom burden are associated with decline in BNP levels.