Background. Normothermic machine perfusion (NMP) protocols using blood-based solutions are commonly used in the assessment of kidneys before transplantation. This procedure is, nevertheless, limited by blood availability and warrants the search for alternatives. We compared a blood-based solution with a serum-like preservation solution (Aqix) enriched with colloids with and without red blood cells (RBCs). Methods. Porcine kidneys retrieved from an abattoir were subjected to 30 min of warm ischemia, followed by 3 h of hypothermic oxygenated machine perfusion at 4 °C. Subsequently, kidneys (n = 6 per group) were evaluated with NMP for 4 h with 5 different solutions: diluted blood, Aqix with BSA ± RBCs, or Aqix with dextran 40 ± RBCs. Results. Throughout NMP, markers of renal function and tubular metabolism were favorable in groups with RBCs. The addition of RBCs resulted in 4- to 6-fold higher oxygen consumption rates. Controls had significantly higher ATP levels post-NMP, exhibited decreased production of oxidative stress markers, and had the highest creatinine clearance. In conclusion, this study shows that the addition of RBCs during NMP reduced renal injury, improved function, and was associated with increased renal metabolism. Conclusions. Although the RBC-BSA–supplemented Aqix solution was also able to support metabolism and renal function, a blood-based perfusion solution remains superior.
SUMMARY Assessment of donor kidney quality is based on clinical scores or requires biopsies for histological assessment. Noninvasive strategies to identify and predict graft outcome at an early stage are, therefore, needed. We evaluated the perfusate of donation after brain death (DBD) kidneys during nonoxygenated hypothermic machine perfusion (HMP). In particular, we compared perfusate protein profiles of good outcome (GO) and suboptimal outcome (SO) 1‐year post‐transplantation. Samples taken 15 min after the start HMP (T1) and before the termination of HMP (T2) were analysed using quantitative liquid chromatography–tandem mass spectrometry (LC‐MS/MS). Hierarchical clustering of the 100 most abundant proteins showed discrimination between grafts with a GO and SO at T1. Elevated levels of proteins involved in classical complement cascades at both T1 and T2 and a reduced abundance of lipid metabolism at T1 and of cytoskeletal proteins at T2 in GO versus SO was observed. ATP‐citrate synthase and fatty acid‐binding protein 5 (T1) and immunoglobulin heavy variable 2‐26 and desmoplakin (T2) showed 91% and 86% predictive values, respectively, for transplant outcome. Taken together, DBD kidney HMP perfusate profiles can distinguish between outcome 1‐year post‐transplantation. Furthermore, it provides insights into mechanisms that could play a role in post‐transplant outcomes.
Great efforts have been made toward addressing the demand for donor kidneys. One of the most promising approaches is to use kidneys from donation after circulatory death donors. These kidneys, however, suffer from more severe ischemia and reperfusion injury than those obtained via donation after brain death and are thus more prone to develop interstitial fibrosis and tubular atrophy. Even though machine perfusion is increasingly used to reduce ischemia and reperfusion injury, there are no effective treatments available to ameliorate interstitial fibrosis and tubular atrophy, forcing patients to resume dialysis, undergo re-transplantation, or suffer from premature death. Safe and effective anti-fibrotic therapies are therefore greatly desired. We propose a new therapeutic approach in which machine perfusion solutions are supplemented with anti-fibrotic compounds. This allows the use of higher concentrations than those used in humans whilst eliminating side effects in other organs. To the authors' knowledge, no one has reviewed whether such an approach could reduce interstitial fibrosis and tubular atrophy; we therefore set out to explore its merit. In this review, we first provide background information on ischemia and reperfusion injury as well as interstitial fibrosis and tubular atrophy, after which we describe currently available approaches for preserving donor kidneys. We then present an evaluation of selected compounds. To identify promising compounds, we analyzed publications describing the effects of anti-fibrotic molecules in precision-cut kidneys slices, which are viable explants that can be cultured ex vivo for up to a few days whilst retaining functional and structural features. LY2109761, galunisertib, imatinib, nintedanib, and butaprost were shown to exert anti-fibrotic effects in slices within a relatively short timeframe (<48 h) and are therefore considered to be excellent candidates for follow-up ex vivo machine perfusion studies.
Marginal donor kidneys are more likely to develop ischemia-reperfusion injury (IRI), resulting in inferior long-term outcomes. Perfusion techniques are used to attenuate IRI and improve graft quality. However, machine perfusion is still in its infancy, and more research is required for optimal conditions and potential repairing therapies. Experimental machine perfusion using porcine kidneys is a great way to investigate transplant-related IRI, but these experiments are costly and time-consuming. Therefore, an intermediate model to study IRI would be of great value. We developed a precision-cut kidney slice (PCKS) model that resembles ischemia-reperfusion and provides opportunities for studying multiple interventions simultaneously. Porcine kidneys were procured from a local slaughterhouse, exposed to 30 min of warm ischemia, and cold preserved. Subsequently, PCKS were prepared and incubated under various conditions. Adenosine triphosphate (ATP) levels and histological tissue integrity were assessed for renal viability and injury. Slicing did not influence tissue viability, and PCKS remained viable up to 72 h incubation with significantly increased ATP levels. Hypothermic and normothermic incubation led to significantly higher ATP levels than baseline. William’s medium E supplemented with Ciprofloxacin (and Amphotericin-B) provided the most beneficial condition for incubation of porcine PCKS. The porcine PCKS model can be used for studying transplant IRI.
Circulatory death donor (DCD) kidneys are increasingly used to enlarge the donor pool. These kidneys undergo ischemia-reperfusion injury, frequently leading to renal fibrosis. Transforming growth factor beta 1 (TGF-β1) and matrix metalloproteases have been identified as central mediators of fibrosis and inhibition of these targets could attenuate fibrosis. We studied whether galunisertib, doxycycline, taurine, and febuxostat alleviated fibrosis in precision-cut kidney slices (PCKS). PCKS were prepared from porcine kidneys that were exposed to 30 min of warm ischemia followed by 3 h of oxygenated hypothermic machine perfusion. We subsequently incubated PCKS for 48 h at 37 °C with the described compounds. To further elucidate the antifibrotic effects of galunisertib, we cultured PCKS with TGF-β1. We first screened the effects of the compounds without TGF-β1. Most significant effects were observed for galunisertib which lowered the expression of ACTA2, TGFB1, FN2, and SERPINE1. We then investigated the effects of galunisertib in fibrotic PCKS incubated with TGF-β1. TGF-β1 significantly increased expression of TGFB1, FN1, SERPINE1, and SERPINH1. Galunisertib, however, attenuated the expression of all fibrosis-related genes. Galunisertib appears to be a promising antifibrotic compound requiring further research in a preclinical model and may ultimately be administered during machine perfusion as an antifibrotic treatment in a transplant setting.
IntroductionRoutine assessment of patient-reported outcomes (PROs) in oncology has shown to improve the quality of the delivered care and to prolong survival. However, for successful implementation of routine assessment of PROs, more knowledge on their usability in clinical practice is needed.ObjectiveThis study aimed to cross-sectionally assess the perspective of patients and clinicians on the practicality of routinely measuring PROs in clinical practice for glioma patients.MethodsSemistructured interviews were conducted evaluating the role of healthcare professionals (HCP) in discussing results of PRO measures (PROMs), and the preferred topics, methods and frequency of PRO assessment. Glioma patients, their proxies and HCPs involved in the treatment of glioma patients from eight centres in the Netherlands were included.ResultsTwenty-four patients, 16 proxies and 35 HCPs were interviewed. The majority of patients, proxies and HCPs (92%, 81% and 80%, respectively) were willing to discuss PRO results during consultations. Although HCPs prefer that results are discussed with the nurse specialist, only one-third of patients/proxies agreed. Functioning of daily life was considered important in all three groups. Most participants indicated that discussion of PROM results should take place during standard follow-up visits, and completed at home about 1 week in advance. On group level, there was no preference for administration of questionnaires on paper or digitally. Lastly, all centres had staff available to send questionnaires on paper.ConclusionThis study shows that routine assessment of PROs is desired by patients, proxies and HCP’s in neuro-oncological care in Dutch hospitals.
Normothermic machine perfusion is an emerging preservation technique for kidney allografts to reduce post-transplant complications, including interstitial fibrosis and tubular atrophy. This technique, however, could be improved by adding antifibrotic molecules to perfusion solutions. We established Machine perfusion and Organ slices as a Platform for Ex vivo Drug delivery (MOPED), to explore fibrogenesis suppression strategies. We perfused porcine kidneys ex vivo with galunisertib, a potent inhibitor of the transforming growth factor beta signaling pathway. To determine whether effects persisted, we also cultured precision-cut tissue slices prepared from the respective kidneys. Galunisertib supplementation improved the general viability, without negatively affecting renal function or elevating levels of injury markers or byproducts of oxidative stress. Galunisertib also reduced inflammation and more importantly, strongly suppressed the onset of fibrosis, especially when the treatment was continued in slices. Our results illustrate the value of targeted drug delivery, using isolated organ perfusion, for reducing post-transplant complications.
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