Pre-transplantation 31P-magnetic resonance spectroscopy for quality assessment of human pancreatic grafts – A feasibility study

Abstract

ObjectiveTo investigate the feasibility of using 31P-MRS for objective non-invasive quality assessment of human pancreas grafts prior to transplantation or islet isolation. Materials and methodsPancreata from 5 human donors, 3 males and 2 females, aged 49–78years, with body mass index (BMI) 22–31kg/m2, were included. Pancreata were perfused with histidine-tryptophan-ketoglutarate solution during procurement and stored in hypothermic condition (4°C) for 21–44h. During the period of hypothermic storage repeated spectra were obtained for each graft by 31P-MRS (1.5Tesla) to measure the cold ischemia time (CIT) dependent changes of the phosphorous metabolites adenosine triphosphate (ATP), phosphomonoesters (PME), phosphodiesters (PDE) and inorganic phosphate (Pi), in the grafts. Graft temperature was measured immediately before and after MR-examination. Reference spectrum for non-viable tissue was obtained after graft exposure to room temperature. ResultsPME/Pi, PDE/Pi and ATP/Pi spectral intensities ratios decreased with increasing CIT, reflecting the decreased viability of the grafts. PME/Pi ratio was the most discriminatory variable at prolonged CIT. 31P-MRS could be performed without significantly increasing graft temperature. Conclusions31P-MRS may provide quantitative parameters for evaluating graft viability ex vivo, and is a promising tool for objective non-invasive assessment of the quality of human pancreas grafts prior to transplantation or islet isolation.