The Influence of Warm Ischemic Time on the Viability of Deceased Organ Donor Derived Bone Marrow

Abstract

It was recognized 60 years ago that deceased donor bone marrow (BM) could be a useful source of viable hematopoietic stem cells (HSCs) for transplantation. Validated procedures have since been published for the recovery of viable deceased donor HSCs and their safe use in immune tolerance clinical trials. It is the goal of Ossium Health to streamline the process of obtaining deceased donor derived BM on an industrial scale. It has been shown by previous studies that BM is tolerant to a wide range of cold and warm ischemic times during collection. CD34+ HSCs prefer a hypoxic environment and remain quiescent in vivo. This observation indicates that BM procured during routine organ and tissue recovery may remain viable for extended periods following cardiac arrest and, thus, will be suitable for transplantation. Ossium is evaluating the range of ischemia times to determine if organ and tissue donor bone marrow recovered using a standardized approach is suitable for transplantation.Vertebral bodies (VBs) and ilia of 34 deceased organ donors were recovered by Ossium's network of organ procurement organizations (OPOs) over warm ischemia times ranging from 1:03–22:03 (hr:min). Recovered VBs were then cooled and shipped overnight on wet ice to Ossium Health, Indianapolis, IN, for BM recovery using grinding and elution methods. The CD34+ HSC population was enumerated using flow cytometric ISHAGE protocols and a mean viability over the entire ischemia range was determined to be 79.3 ± 3.7% (mean ± SEM) as determined by 7‐Aminoactinomycin D (7‐AAD).While gross membrane viability is a useful measure, engraftment potential correlates strongly with functional viability as measured through colony forming unit (CFU) assay, and engraftment of transplanted units requires the presence of Granulocyte/Macrophage (GM) colonies specifically. To confirm that the deceased donor marrow would be suitable for engraftment, the CFU assay was performed and CFU‐GM were scored. Over the entire range of ischemic times, an average of 37.05 ±11.16 CFU‐GM (mean ± SEM) per 105 nucleated cells plated was observed.Rapid neutrophil and platelet engraftment in living donor allogeneic grafts has previously been correlated with a dose containing CFU‐GM of 5.6 per 105 TNC in for an average patient of 70kg. The results of this preliminary study indicate deceased donor marrow can easily meet this requirement. These data demonstrate the potential to recover viable and functional HSCs after extended periods of warm ischemia; thus, establishing the feasibility and utility of banking cells from deceased organ and tissue donors.Support or Funding InformationThis work was funded by a Grant from the NIH‐NIAID (1R43AI129444‐01A1, PI: Woods, EJ), and Ossium Health, Inc.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.