1H MAS NMR of Donor Pancreatic Tissue is a Useful Predictor of Islet Viability Prior to Islet Isolation

Abstract

AbstractA significant limitation and cost to any clinical islet program is the related to processing human pancreas and not recovering significant numbers of viable islets for clinical transplantation. The development of an assay system that could be utilized and provide an index of cell and tissue viability before islet isolation would provide a major impact on the scientific aspects of organ preservation and a huge cost saving to any clinical islet transplantation program.Metabolomic analysis by 1H MAS NMR was used to assess samples of donor pancreatic tissue taken prior to islet isolation. A significant correlation was observed between the ratio of the combined integrals of the sugar (3.5-4.5 ppm) and choline (3.0-3.5 ppm) regions to the integrals of the CH3 (0.9 ppm) and CH2 (1.3 ppm) peaks of the 1H MAS NMR spectra of pancreatic tissue samples taken prior to islet isolation and the glucose responsiveness, a measure of islet viability, of the isolated islets (P<0.05). The effect of the two-layer (University of Wisconsin solution/perfluorochemical [UW/PFC]) cold-storage method, previously shown to restore ischemically damaged pancreases by increasing oxygenation, was also studied using 1H MAS NMR spectroscopy. PFC recovery of the donor pancreas also correlated with an increase in the combined integrals of the sugar and choline regions to the CH3 and CH2 peaks of the 1H MAS NMR spectra (P<0.05). In addition, significant differences in the integrals of the sugar region and CH2 peaks were observed between the pre- and post-PFC samples (P<0.05). These results support the notion that specific metabolites observed in 1H MAS NMR can be used as a means to assess reversible/irreversible tissue damage and offers a means to assess donor pancreatic tissue prior to islet isolation for transplantation.