Impact of active oxygenation and oxygen carrier during the kidney transplant preservation in machine perfusion before transplantation

Il est prouvé que la conservation des greffons rénaux marginaux en machine de perfusion (MP) est bénéfique. Cependant, cette méthode nécessite des améliorations afin de minimiser les lésions d’ischémie-reperfusion (I/R), par l’ajout d’oxygène et/ou d’un transporteur d’oxygène. Nous avons cherché à évaluer les effets de l’oxygénation et de l’ajout d’une hémoglobine de ver marin (HbAm, M101) durant la perfusion rénale hypothermique avant transplantation. Nos critères de jugement étaient basés sur la reprise de fonction du greffon et sur les lésions tardives de dysfonction rénale. Nous avons utilisé un modèle porcin : les reins ont été exposés à 1h d’ischémie chaude, puis perfusés dans une MP WAVES® pendant 23h à 4°C avant autotransplantation. Quatre groupes ont étudié : W (MP-21% O2), W-O2 (MP-100% O2), W-M101 (MP-21% O2 + 2g/L HbAm), W-O2+M101 (100% O2 + 2g/L HbAm), (n=6 per groupe). Les reins du groupe W-M101 ont montré un débit de perfusion plus élevé et une résistance rénale plus faible comparé aux autres groupes. Pendant la première semaine post-transplantation, les groupes W-O2 et W-M101 ont montré une créatininémie significativement plus faible et un meilleur taux de filtration glomérulaire (GFR). Les niveaux circulants de KIM-1 et IL-18 étaient plus faibles dans le groupe W-M101, tandis que les niveaux de NGAL et d’ASAT étaient plus faibles dans les groupes d’oxygénation active. Trois mois post-transplantation, la fraction excrétée de sodium et le ratio protéinurie/créatininurie étaient plus élevé dans le groupe W. La créatininémie était plus faible dans le groupe W-M101. La fibrose interstitielle a évalué à 3 mois post-transplantation étaient plus faible dans les groupes W-M101 et W-O2+M101. Nous avons révélé histologiquement que l’infiltration de mastocytes était significativement élevée dans le groupe W comparé aux autres groupes. Nous avons montré que la combinaison de 21% O2 + hémoglobine améliorent la reprise de fonction du greffon rénale.Introduction: It is proved that preservation of marginal kidney graft in machine perfusion (MP) is beneficial. However, this method requires improvement to minimize the ischemia-reperfusion injuries (IRI), as addition of oxygen and/or an oxygen carrier. We aimed to evaluate the effects of oxygenation (100% or 21%) and the addition of marine worm hemoglobin (HbAm, M101) during hypothermic renal perfusion before transplantation. Our endpoints were based on graft function recovery and late renal dysfunction. Method and materials: We use a porcine model where kidneys were submitted to 1h warm ischemia, followed by WAVES® MP preservation for 23h before auto-transplantation. Four groups were studied: W (MP-21% O2), W-O2 (MP-100% O2), W-M101 (MP-21% O2 + 2g/L HbAm), W-O2+M101 (100% O2 + 2g/L HbAm), (n=6 per group). Results: Kidneys preserved in W-M101 group showed a higher perfusion flow and lower renal resistance, compared to other groups. During the first week post-transplantation, W-O2 or W-M101 groups showed lower blood creatinine and better glomerular filtration rate. Blood levels of KIM-1 and IL-18 were lower in W-M101 group, while blood levels of AST and NGAL were lower in groups with 100% O2. Three months after transplantation, the fractional excretion of sodium and the proteinuria/ creatininuria ratio were higher in W group. Blood creatinine was lower in W-M101 group. Interstitial fibrosis evaluated at 3 months was lower in groups W-M101 and W-O2+M101. We showed that the combination 21% O2 + hemoglobin improves the kidney graft outcome.Conclusion: We showed that the combination of 21% O2 + hemoglobin improved the kidney graft outcome

Impact de l'oxygénation active et d'un transporteur d'oxygène durant la conservation des greffons rénaux sur machine de perfusion avant transplantation

Introduction: It is proved that preservation of marginal kidney graft in machine perfusion (MP) is beneficial. However, this method requires improvement to minimize the ischemia-reperfusion injuries (IRI), as addition of oxygen and/or an oxygen carrier. We aimed to evaluate the effects of oxygenation (100% or 21%) and the addition of marine worm hemoglobin (HbAm, M101) during hypothermic renal perfusion before transplantation. Our endpoints were based on graft function recovery and late renal dysfunction. Method and materials: We use a porcine model where kidneys were submitted to 1h warm ischemia, followed by WAVES® MP preservation for 23h before auto-transplantation. Four groups were studied: W (MP-21% O2), W-O2 (MP-100% O2), W-M101 (MP-21% O2 + 2g/L HbAm), W-O2+M101 (100% O2 + 2g/L HbAm), (n=6 per group). Results: Kidneys preserved in W-M101 group showed a higher perfusion flow and lower renal resistance, compared to other groups. During the first week post-transplantation, W-O2 or W-M101 groups showed lower blood creatinine and better glomerular filtration rate. Blood levels of KIM-1 and IL-18 were lower in W-M101 group, while blood levels of AST and NGAL were lower in groups with 100% O2. Three months after transplantation, the fractional excretion of sodium and the proteinuria/ creatininuria ratio were higher in W group. Blood creatinine was lower in W-M101 group. Interstitial fibrosis evaluated at 3 months was lower in groups W-M101 and W-O2+M101. We showed that the combination 21% O2 + hemoglobin improves the kidney graft outcome.Conclusion: We showed that the combination of 21% O2 + hemoglobin improved the kidney graft outcome.Il est prouvé que la conservation des greffons rénaux marginaux en machine de perfusion (MP) est bénéfique. Cependant, cette méthode nécessite des améliorations afin de minimiser les lésions d’ischémie-reperfusion (I/R), par l’ajout d’oxygène et/ou d’un transporteur d’oxygène. Nous avons cherché à évaluer les effets de l’oxygénation et de l’ajout d’une hémoglobine de ver marin (HbAm, M101) durant la perfusion rénale hypothermique avant transplantation. Nos critères de jugement étaient basés sur la reprise de fonction du greffon et sur les lésions tardives de dysfonction rénale. Nous avons utilisé un modèle porcin : les reins ont été exposés à 1h d’ischémie chaude, puis perfusés dans une MP WAVES® pendant 23h à 4°C avant autotransplantation. Quatre groupes ont étudié : W (MP-21% O2), W-O2 (MP-100% O2), W-M101 (MP-21% O2 + 2g/L HbAm), W-O2+M101 (100% O2 + 2g/L HbAm), (n=6 per groupe). Les reins du groupe W-M101 ont montré un débit de perfusion plus élevé et une résistance rénale plus faible comparé aux autres groupes. Pendant la première semaine post-transplantation, les groupes W-O2 et W-M101 ont montré une créatininémie significativement plus faible et un meilleur taux de filtration glomérulaire (GFR). Les niveaux circulants de KIM-1 et IL-18 étaient plus faibles dans le groupe W-M101, tandis que les niveaux de NGAL et d’ASAT étaient plus faibles dans les groupes d’oxygénation active. Trois mois post-transplantation, la fraction excrétée de sodium et le ratio protéinurie/créatininurie étaient plus élevé dans le groupe W. La créatininémie était plus faible dans le groupe W-M101. La fibrose interstitielle a évalué à 3 mois post-transplantation étaient plus faible dans les groupes W-M101 et W-O2+M101. Nous avons révélé histologiquement que l’infiltration de mastocytes était significativement élevée dans le groupe W comparé aux autres groupes. Nous avons montré que la combinaison de 21% O2 + hémoglobine améliorent la reprise de fonction du greffon rénale

Individual and Combined Impact of Oxygen and Oxygen Transporter Supplementation during Kidney Machine Preservation in a Porcine Preclinical Kidney Transplantation Model

Marginal kidney graft preservation in machine perfusion (MP) is well-established. However, this method requires improvement in order to mitigate oxidative stress during ischemia-reperfusion, by using oxygenation or an O2 carrier with anti-oxidant capacities (hemoglobin of the marine worm; M101). In our preclinical porcine (pig related) model, kidneys were submitted to 1h-warm ischemia, followed by 23 h hypothermic preservation in Waves® MP before auto-transplantation. Four groups were studied: W (MP without 100%-O2), W-O2 (MP with 100%-O2; also called hyperoxia), W-M101 (MP without 100%-O2 + M101 2 g/L), W-O2 + M101 (MP with 100%-O2 + M101 2 g/L) (n = 6/group). Results: Kidneys preserved in the W-M101 group showed lower resistance, compared to our W group. During the first week post-transplantation, W-O2 and W-M101 groups showed a lower blood creatinine and better glomerular filtration rate. KIM-1 and IL-18 blood levels were lower in the W-M101 group, while blood levels of AST and NGAL were lower in groups with 100% O2. Three months after transplantation, fractional excretion of sodium and the proteinuria/creatinuria ratio remained higher in the W group, creatininemia was lower in the W-M101 group, and kidney fibrosis was lower in M101 groups. We concluded that supplementation with M101 associated with or without 100% O2 improved the Waves® MP effect upon kidney recovery and late graft outcome

Efficacy of the natural oxygen transporter HEMO 2 life ® in cold preservation in a preclinical porcine model of donation after cardiac death

International audienceThe growing use of marginal organs for transplantation pushes current preservation methods toward their limits, and the need for improvement is pressing. We previously demonstrated the benefits of M101, a natural extracellular oxygen carrier compatible with hypothermia, for the preservation of healthy renal grafts in a porcine model of autotransplantation. Herein, we use a variant of this preclinical model to evaluate M101 potential benefits both in static cold storage (CS) and in machine perfusion (MP) preservation in the transplantation outcomes for marginal kidneys. In the CS arm, despite the absence of obvious benefits within the first 2 weeks of follow-up, M101 dose-dependently improved long-term function, normalizing creatininemia after 1 and 3 months. In the MP arm, M101 improved short- and long-term functional outcomes as well as tissue integrity. Importantly, we provide evidence for the additivity of MP and M101 functional effects, showing that the addition of the compound further improves organ preservation, by reducing short-term function loss, with no loss of function or tissue integrity recorded throughout the follow-up. Extending previous observations with healthy kidneys, the present results point at the M101 oxygen carrier as a viable strategy to improve current organ preservation methods in marginal organ transplantation

Preventing acute kidney injury during transplantation: the application of novel oxygen carriers

International audienceIntroduction: Delayed graft function (DGF) has a significant impact on kidney transplantation outcome. One of the underlying pivotal mechanisms is organ preservation and associated hypothermia and biochemical alteration. Area covered: This paper focuses on organ preservation and its clinical consequences and describes 1. A comprehensive presentation of the pathophysiological mechanism involved in delayed graft function development; 2. The impact on endothelial cells and microvasculature integrity and the consequences on transplanted organ outcome; 3. The reassessment of dynamic organ preservation motivated by the growing use of extended criteria donors and the interest in the potential of normothermia; 4. The role of oxygenation during dynamic preservation; and 5. Novel oxygen carriers and their proof of concept in transplantation, among which M101 (HEMO(2)life (R)) is currently the most extensively investigated. Expert opinion: Metabolic disturbances and imbalance of oxygen supply during preservation highlight the importance of providing oxygen. Normothermia, permitted by recent advances in machine perfusion technology, appears to be the leading edge of preservation technology. Several oxygen transporters are compatible with normothermia; however, only M101 also demonstrates compatibility with standard hypothermic preservation