A lectin affinity plasmapheresis device removes extracellular vesicles and microRNAs from renal perfusates following controlled oxygenated rewarming of discarded donor kidneys

Kidney transplantation is considered the benchmark treatment for end-stage kidney disease patients, yet the scarcity of suitable kidneys poses a significant hindrance for patients and healthcare providers. One approach is to extend the criteria for the use of kidneys from deceased brain death and deceased circulatory death donors. Use of these organs, especially from these extended criteria donors, is associated with ischemia reperfusion injury and resultant delayed graft function as well as increased rates of allograft rejection. To lessen these complications as well as increase the time of organ viability assessment, machine perfusion has been evaluated on recovered kidneys. In this study we examined the immunogenic molecular content of perfusates from discarded organs that had undergone Controlled Oxygenated Rewarming (COR). Perfusates were analyzed for extracellular vesicles (EVs), DNA (Deoxyribonucleic acid), and microRNAs. These perfusates were then pumped over a plasma separator containing a lectin affinity resin. Following treatment, a significant diminution in extracellular vesicles, dsDNA (double-stranded DNA) associated with EVs, and microRNAs (miRNA) were observed. Specifically, in three out of the four renal perfusates analyzed there was significant removal of small EVs (<200 nm) and vesicles loaded with dsDNA (p < 0.05). Notably, depletion of larger EVs (100-500 nm) was found to be significant in all treated perfusates (p < 0.01). NanoString analysis of miRNA found 5 species potentially involved in renal dysfunction (hsa-let 7a-5p, hsa-miR-148b-3p, hsa-miR-148a-3p, hsa-miR-29b-3pb and hsa-miR-99a5p) to be significantly depleted in treated renal perfusates (p ≤ 0.05). These results support a future study incorporating this treatment method into a dynamic machine perfusion circuit to explore if reduction of these mediators is associated with improved function of retrieved kidneys.