Perfusion Techniques in Kidney Allograft Preservation to Reduce Ischemic Reperfusion Injury: A Systematic Review and Meta-Analysis.

The limited supply and rising demand for kidney transplantation has led to the use of allografts more susceptible to ischemic reperfusion injury (IRI) and oxidative stress to expand the donor pool. Organ preservation and procurement techniques, such as machine perfusion (MP) and normothermic regional perfusion (NRP), have been developed to preserve allograft function, though their long-term outcomes have been more challenging to investigate. We performed a systematic review and meta-analysis to examine the benefits of MP and NRP compared to traditional preservation techniques. PubMed (MEDLINE), Embase, Cochrane, and Scopus databases were queried, and of 13,794 articles identified, 54 manuscripts were included (n = 41 MP; n = 13 NRP). MP decreased the rates of 12-month graft failure (OR 0.67; 95%CI 0.55, 0.80) and other perioperative outcomes such as delayed graft function (OR 0.65; 95%CI 0.54, 0.79), primary nonfunction (OR 0.63; 95%CI 0.44, 0.90), and hospital length of stay (15.5 days vs. 18.4 days) compared to static cold storage. NRP reduced the rates of acute rejection (OR 0.48; 95%CI 0.35, 0.67) compared to in situ perfusion. Overall, MP and NRP are effective techniques to mitigate IRI and play an important role in safely expanding the donor pool to satisfy the increasing demands of kidney transplantation.

Donor Lung Preservation at 10°C: Clinical and Logistical Impact.

INTRODUCTION: Cold static donor lung preservation at 10°C appears to be a promising method to safely extend the cold ischemic time (CIT) and improve lung transplant (LTx) logistics. METHODS: LTx from November 2021 to February 2023 were included in this single institution, prospective, non-randomized study comparing prolonged preservation at 10°C versus standard preservation on ice. The inclusion criteria for 10°C preservation were suitable grafts for LTx without any donor retrieval concerns. PRIMARY ENDPOINT: primary graft dysfunction (PGD) grade-3 at 72-h. Secondary endpoints: clinical outcomes, cytokine profile and logistical impact. RESULTS: Thirty-three out of fifty-seven cases were preserved at 10°C. Donor and recipient characteristics were similar across the groups. Total preservation times (h:min) were longer (p<0.001) in the 10°C group [1st lung: median 12:09 (IQR 9:23-13:29); 2nd: 14:24 (12:00-16:20)] vs. standard group [1st lung: median 5:47 (IQR 5:18-6:40); 2nd: 7:15 (6:33-7:40)]. PGD grade-3 at 72-h was 9.4% in 10°C group vs. 12.5% in standard group (p=0.440). Length of mechanical ventilation (MV), ICU and hospital stays were similar in both groups. Thirty and ninety-day mortality rates were 0% in 10°C group (vs. 4.2% in standard group). IL-8 concentration was significantly higher 6-h post-LTx in the standard group (p=0.025) and IL-10 concentration was increased 72-h post-LTx in the 10°C group (p=0.045). CONCLUSIONS: Preservation at 10°C may represent a safe and feasible strategy to intentionally prolong the CIT. In our center, extending the CIT at 10°C may allow for semi-elective LTx and improve logistics with similar outcomes compared to the current standard preservation on ice.

Ascorbic acid enhances the cold preservation period of human adipose tissue-derived mesenchymal stromal cells.

Introduction: We previously developed 3% trehalose-added lactated Ringer's solution (LR-3T) and 3% trehalose- and 5% dextran-40-added lactated Ringer's solution (LR-3T-5D), which can be used to preserve adipose-derived mesenchymal stem cells (hADSCs) for 24 h at 5 and 25 °C. However, it is necessary to further extend the storage duration of cells to expand transportation zones and ensure time for quality control testing of final cell products. Therefore, we attempted to prolong the preservation duration of hADSCs by adding supplements to LR-3T-5D. We focused on ascorbic acid as an antioxidant because it is widely clinically as a nutrient. Methods: We added the antioxidant ascorbic acid to LR-3T-5D and evaluated the viability, colony formation rate, proliferative capacity, and surface markers of hADSCs before and after preservation at 5 °C. Results: Analysis of the concentration of ascorbic acid added to LR-3T-5D indicated that 1000 mg/L was the optimal concentration for maintaining the viability of hADSCs after 72 h of cold preservation. No changes were observed in the expression of specific cell surface markers or in the potential of hADSCs to differentiate into adipocytes, osteoblasts, or chondrocytes before and after cold preservation. Discussion: These results suggest that cold preservation of hADSCs in LR-3T-5D supplemented with ascorbic acid helps maintain the quality of cells for use in cell therapy.

Donor lungs cold preservation at 10 ºC offers a potential logistic advantage in lung transplantation / La preservación fría a 10 ºC de los injertos ofrece ventajas logísticas en el trasplante pulmonar

Donor lung preservation at 10 °C appears to be an innovative and promising method that may improve transplant logistics by extending the cold ischemia time with excellent outcomes. We report the case of two lung transplants from two different donors involving the use of two different preservation methods, highlighting the benefits of using 10 °C lung storage. (AU)

La preservación pulmonar a 10 °C es una estrategia innovadora que podría mejorar la logística del trasplante pulmonar permitiendo prolongar el tiempo de isquemia fría de los injertos pulmonares con excelentes resultados. Presentamos el caso de dos trasplantes pulmonares de dos donantes diferentes empleando dos métodos de preservación distintos, recalcando los beneficios de utilizar este novedoso método de preservación a 10 °C. (AU)

Influence of trans-ferulic acid on the quality of ram semen upon cold preservation.

BACKGROUND: Due to lower antioxidant capacity and higher amounts of polyunsaturated fatty acids, ram spermatozoa are very susceptible during cooling process. OBJECTIVES: The objective was to examine the effect of the trans-ferulic acid (t-FA) on the ram semen during liquid preservation. METHODS: Semen samples were collected from the Qezel rams, pooled, and extended with the Tris-based diluent. Pooled samples enriched with different amounts of the t-FA (0, 2.5, 5, 10, and 25 mM) and preserved at 4°C for 72 h. Spermatozoa's kinematics, membrane functionality, and viability were assessed by CASA system, hypoosmotic swelling test, and eosin-nigrosin staining, respectively. Moreover, biochemical parameters were measured at 0, 24, 48, and 72 h. RESULTS: Results showed that 5 and 10 mM t-FA improved forward progressive motility (FPM) and curvilinear velocity compared to the other groups at 72 h (p < 0.05). Samples treated with 25 mM t-FA showed the lowest total motility, FPM, and viability at 24, 48, and 72 h of storage (p < 0.05). Higher total antioxidant activity levels were observed in the 10 mM t-FA-treated group compared to the negative control at 72 h (p < 0.05). Treatment with 25 mM t-FA increased malondialdehyde amounts and decreased superoxide dismutase activity compared to other groups at the final time assessment (p < 0.05). Nitrate-nitrite and lipid hydroperoxides values were not affected by treatment. CONCLUSIONS: The current study indicates the positive and negative influences of different concentrations of t-FA on the ram semen upon cold storage.

Donor lungs cold preservation at 10 °C offers a potential logistic advantage in lung transplantation.

Donor lung preservation at 10 °C appears to be an innovative and promising method that may improve transplant logistics by extending the cold ischemia time with excellent outcomes. We report the case of two lung transplants from two different donors involving the use of two different preservation methods, highlighting the benefits of using 10 °C lung storage.

Controlled temperatures in cold preservation provides safe heart transplantation results.

BACKGROUND: We aimed to investigate the short-term outcomes of heart transplant patients who underwent SherpaPak™ donor organ preservation. METHOD: We prospectively collected the data of patients who underwent heart transplantation using SherpaPak™ system for donor organ transportation from February 2020 to March 2021. Donor and recipient demographic data, preoperative and postoperative echocardiographic and hemodynamic parameters, total ischemic time and SherpaPak temperatures, vasoactive inotropic scores (VIS), primary graft dysfunction (PGD) status, intensive care unit stay, complications, and mortality during follow-up were assessed. RESULTS: A total of 39 consecutive heart transplant patients with SherpaPak system were included in the study. The mean donor age was 32.2 ± 6.7 (range: 16-46). The mean recipient age was 57.5 ± 12 (range: 19-73). The mean preoperative ejection fraction (EF) was 23.7 ± 15.4 (range: 5-75). All recipients underwent a standard bicaval technique for orthotopic heart implantation. The mean total ischemic time was 230.1 ± 41 (range: 149-342) min. The mean Sherpa temperature was 5.6 ± 0.8°C (range: 3.7-7.5). The mean VIS was 10.2 ± 6.5 (range: 2-32). The number of mild PGD was 5 (14.7%), and moderate PGD was 4 (11.8%). There was no severe PGD. The postoperative EF was 64.3 ± 5.5 (range: 50-78). Mean intubation time was 47.4 ± 64 (range: 8-312, median: 22) h. The mean time of intensive care unit stay was 6.3 ± 5 (range: 2-31, median: 5) days. Two patients required chest revision (5.8%), two patients had lung infection (5.8%). Two patients had a stroke (5.8%). There was no mortality. CONCLUSION: Using the SherpaPak system during heart transplantation is safe and not associated with significant recipient morbidity. None of the recipients experienced significant PGD and mortality.

Bioactive peptides supplemented raw buffalo milk: Biological activity, shelf life and quality properties during cold preservation.

This study aimed to prolong the raw buffalo milk handling and cold storage period by controlling the microbes, enhancing sensory properties and their functionality after supplementing bioactive peptides. The additions included hen and duck egg white protein isolates (HPI and DPI), pepper seed protein (PSP), and pepsin-kidney bean protein hydrolysate (PKH). Five milk treatments were prepared and evaluated as non-supplemented milk (M- Control), hen egg white protein isolate-supplemented milk (M-HPI), duck egg white protein isolate-supplemented milk (M-DPI), pepper seeds protein-supplemented milk (M-PSP), and kidney bean hydrolysate-supplemented milk (M-PKH). Pyrogallol, protocatechuic, catechin, benzoic and caffeine were the main phenolic compounds, Apignin-6-arabinose, naringin, hesperidin, naringenin, kaempferol 3-2-p-comaroyl were the dominant flavonoids in milk samples based on HPLC profile. During 30 days of cold storage, the antioxidant potential of peptides-supplemented milk samples was significantly decreased (p ≤ 0.05) as decrement of phenolic compounds and flavonoids; the pH was nearly stable, the titratable acidity and total soluble solids (TTS) were (p ≤ 0.05) raised. PSP and PKH were inhibited (p ≤ 0.05) the decay of sugars in M-PSP, and M-PKH by reducing 45% of bacterial load as compared to other milk samples. PSP was significantly (p ≤ 0.05) scavenged 87% of DPPH compared to other peptides. Besides, PSP followed by PKH reduced considerably (p ≤ 0.05) the growth of tested bacteria, molds, and yeasts. The PSP has significantly increased the whiteness of M-PSP as compared to other milk samples. M-PSP had the highest score in color, taste, and flavor, followed by M-PKH.

Characterizing Autophagy in the Cold Ischemic Injury of Small Bowel Grafts: Evidence from Rat Jejunum.

Cold ischemic injury to the intestine during preservation remains an unresolved issue in transplantation medicine. Autophagy, a cytoplasmic protein degradation pathway, is essential for metabolic adaptation to starvation, hypoxia, and ischemia. It has been implicated in the cold ischemia (CI) of other transplantable organs. This study determines the changes in intestinal autophagy evoked by cold storage and explores the effects of autophagy on ischemic grafts. Cold preservation was simulated by placing the small intestines of Wistar rats in an IGL-1 (Institute George Lopez) solution at 4 °C for varying periods (3, 6, 9, and 12 h). The extent of graft preservation injury (mucosal and cellular injury) and changes in autophagy were measured after each CI time. Subsequently, we determined the differences in apoptosis and preservation injury after activating autophagy with rapamycin or inhibiting it with 3-methyladenine. The results revealed that ischemic injury and autophagy were induced by cold storage. Autophagy peaked at 3 h and subsequently declined. After 12 h of storage, autophagic expression was reduced significantly. Additionally, enhanced intestinal autophagy by rapamycin was associated with less tissue, cellular, and apoptotic damage during and after the 12-h long preservation. After reperfusion, grafts with enhanced autophagy still presented with less injury. Inhibiting autophagy exhibited the opposite trend. These findings demonstrate intestinal autophagy changes in cold preservation. Furthermore, enhanced autophagy was protective against cold ischemia-reperfusion damage of the small bowels.

The Phenolic Antioxidant 3,5-dihydroxy-4-methoxybenzyl Alcohol (DHMBA) Prevents Enterocyte Cell Death under Oxygen-Dissolving Cold Conditions through Polyphyletic Antioxidant Actions.

Cold preservation in University of Wisconsin (UW) solution is not enough to maintain the viability of the small intestine, due to the oxidative stress. The novel phenolic antioxidant 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA) has dual properties to reduce oxidative stress, radical scavenging, and antioxidant protein induction, in other cells. This study was designed to determine whether DHMBA reduces cold preservation injury of enterocytes, and to identify the effector site. Enterocytes were subjected to 48-h cold preservation under atmosphere in UW solution (±DHMBA), and then returned to normal culture to replicate reperfusion of the small intestine after cold preservation. At the end of cold preservation (ECP) and at 1, 3, 6, and 72 h after rewarming (R1h, R3h, R6h, and R72h), we evaluated cell function and the injury mechanism. The results showed that DHMBA protected mitochondrial function mainly during cold preservation, and suppressed cell death after rewarming, as shown by the MTT, ATP, mitochondrial membrane potential, LDH, and lipid peroxidation assays, together with enhanced survival signals (PI3K, Akt, p70S6K) and induction of antioxidant proteins (HO-1, NQO-1, TRX-1). We found that DHMBA mitigates the cold-induced injury of enterocytes by protecting the mitochondria through direct and indirect antioxidative activities.

Application of dual hypothermic oxygenated machine perfusion in ex vivo split liver transplantation / 器官移植

The technology of split liver transplantation is becoming increasingly mature with rapid development. During ex vivo splitting, the depletion of intracellular energy sources [such as adenosine triphosphate (ATP)] and other metabolic disorders may lead to cell damage and dysfunction, which will be aggravated by reperfusion injury of liver transplantation, clinically manifested as postoperative complications and transplantation failure. To further improve the quality of donor liver in ex vivo split liver transplantation, research teams at home and abroad apply machine perfusion to enhance the quality of donor liver. In this article, the research progresses worldwide on machine perfusion of donor liver in ex vivo split liver transplantation were reviewed, and the application and prospect of dual hypothermic oxygenated machine perfusion (D-HOPE) in ex vivo split liver transplantation were elucidated, aiming to provide reference for increasing the source of donor liver for ex vivo split liver transplantation and further resolving the current status of donorliver shortage.

Current techniques and the future of lung preservation.

Although lung transplant remains the only option for patients suffering from end-stage lung failure, donor supply is insufficient to meet demand. Static cold preservation is the most common method to preserve lungs in transport to the recipient; however, this method does not improve lung quality and only allows for 8 h of storage. This results in lungs which become available for donation but cannot be used due to failure to meet physiologic criteria or an inability to store them for a sufficient time to find a suitable recipient. Therefore, lungs lost due to failure to meet physiological or compatibility criteria may be mitigated through preservation methods which improve lung function and storage durations. Ex situ lung perfusion (ESLP) is a recently developed method which allows for longer storage times and has been demonstrated to improve lung function such that rejected lungs can be accepted for donation. Although greater use of ESLP will help to improve donor lung utilization, the ability to cryopreserve lungs would allow for organ banking to better utilize donor lungs. However, lung cryopreservation research remains underrepresented in the literature despite its unique advantages for cryopreservation over other organs. Therefore, this review will discuss the current techniques for lung preservation, static cold preservation and ESLP, and provide a review of the cryopreservation challenges and advantages unique to lungs.

Heavy Water (D2O) Containing Preservation Solution Reduces Hepatic Cold Preservation and Reperfusion Injury in an Isolated Perfused Rat Liver (IPRL) Model.

BACKGROUND: Heavy water (D2O) has many biological effects due to the isotope effect of deuterium. We previously reported the efficacy of D2O containing solution (Dsol) in the cold preservation of rat hearts. Here, we evaluated whether Dsol reduced hepatic cold preservation and reperfusion injury. METHODS: Rat livers were subjected to 48-hour cold storage in University of Wisconsin (UW) solution or Dsol, and subsequently reperfused on an isolated perfused rat liver. Graft function, injury, perfusion kinetics, oxidative stress, and cytoskeletal integrity were assessed. RESULTS: In the UW group, severe ischemia and reperfusion injury (IRI) was shown by histopathology, higher liver enzymes leakage, portal resistance, and apoptotic index, oxygen consumption, less bile production, energy charge, and reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio (versus control). The Dsol group showed that these injuries were significantly ameliorated (versus the UW group). Furthermore, cytoskeletal derangement was progressed in the UW group, as shown by less degradation of α-Fodrin and by the inactivation of the actin depolymerization pathway, whereas these changes were significantly suppressed in the Dsol group. CONCLUSION: Dsol reduced hepatic IRI after extended cold preservation and subsequent reperfusion. The protection was primarily due to the maintenance of mitochondrial function, cytoskeletal integrity, leading to limiting oxidative stress, apoptosis, and necrosis pathways.

Myocardial protection by propolis during prolonged hypothermic preservation.

Oxidative stress is involved in the pathogenesis of ischemia-reperfusion during myocardial transplantation. Therefore, graft preservation solutions may be improved by supplementation with antioxidants to minimize graft dysfunction caused by cold ischemic injury. Propolis is a polyphenol-rich substance which has an important antioxidant activity. The protective effect of propolis against oxidative stress induced by prolonged cold preservation of heart was investigated. Mice were subjected to a hypothermic model of ischemia in which hearts were preserved for 24 h at 4 °C in Krebs-Hensleit (KH) solution in the absence or presence of propolis concentrations (50, 150 and 250 µg/ml). Levels of released Lactate dehydrogenase (LDH), Creatine phosphokinase (CPK) and Troponine-I (Trop I) were assessed in the preservation solution and histological assessement of heart ischemia injuries was performed. Oxidative stress biomarkers malondialdehyde (MDA) and advanced oxidation protein products (AOPP) and antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were assessed in cardiac tissue. Mitochondria were isolated from stored hearts and production of reactive oxygen species (ROS) was tested. Propolis supplementation protected efficiently hearts during preservation by reducing significantly levels of lipids and proteins oxidation and restoring activities of antioxidant enzymes. Also, propolis preserved tissue integrity altered by hypothermic ischemia in a concentration-dependent manner. Propolis reduced significantly the rate of H2O2 produced by mitochondrial respiration, the best antioxidant effect being obtained at the highest propolis concentration (250 µg/ml). Algerian propolis is a non-temperature sensitive scavenger that protects heart from oxidative damage induced by prolonged hypothermic ischemia.

Efficacy of the natural oxygen transporter HEMO2 life® in cold preservation in a preclinical porcine model of donation after cardiac death.

The 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.

Hypothermic machine perfusion versus static cold preservation in kidney transplantation. / Perfusión hipotérmica de máquina versus preservación en frío estático en el trasplante de riñón.

INTRODUCTION: The adequate preservation of the allograft prior to kidney transplant is key for a good outcome after transplantation. Currently, there are two main methods: hypothermic machine perfusion and static cold preservation. The main objective of this summary is to compare both preservation systems. METHODS: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified 10 systematic reviews including 34 primary studies, of which 13 were randomized trials. We concluded preservation by hypothermic machine perfusion probably decreases the risk of delayed graft function and could lead to a slight increase in graft survival. However, there are no differences in patient survival between the two methods.

INTRODUCCIÓN: La adecuada preservación del aloinjerto previo al trasplante renal es crucial para mantener buenos resultados luego del trasplante. En la actualidad existen dos métodos principales, la perfusión hipotérmica asistida por una máquina y la preservación en frío estático. El objetivo principal de este resumen es comparar ambos sistemas de preservación. MÉTODOS: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos 10 revisiones sistemáticas que en conjunto incluyeron 34 estudios primarios, de los cuales 13 corresponden a ensayos aleatorizados. Concluimos que la preservación mediante perfusión hipotérmica de máquina probablemente disminuye el riesgo de retraso en el funcionamiento del injerto y podría llevar a un leve aumento en la sobrevida del injerto. Sin embargo, no existen diferencias en la sobrevida del paciente entre ambos métodos.

Dopamine in transplantation: Written off or comeback with novel indication?

Renal-dose dopamine has fallen out of favor in the intensive care unit (ICU) during past years due to its ineffectiveness to prevent impending or to ameliorate overt renal failure in the critically ill. By contrast, growing evidence indicates that low-dose dopamine administered to the stable organ donor after brain death confirmation improves the clinical course of transplanted organs after kidney and heart transplantation. Ensuring a thorough monitoring for potential circulatory side effects, employment of dopamine at a dose of 4 µg/kg/min is safe in the deceased donor. Among recipients, the advantageous effect is easy to achieve, inexpensive, and devoid of adverse side effects. The mode of action relies on dopamine's propensity to mitigate injury in various cell systems from isolated transplantable organs under cold storage conditions. The present review article summarizes the clinical evidence of dopamine donor pretreatment in solid organ transplantation and focuses on the underlying molecular mechanisms of cellular protection. Introducing the routine use of low-dose dopamine for the management of the brain-dead donor in the ICU before procurement provides an evidence-based strategy to improve graft outcome after kidney transplantation without conferring harm to non-renal grafts, namely to livers and hearts, in cases of multi-organ donation.

Perfusión hipotérmica de máquina versus preservación en frío estático en el trasplante de riñón / Hypothermic machine perfusion versus static cold preservation in kidney transplantation

INTRODUCCIÓN: La adecuada preservación del aloinjerto previo al trasplante renal es crucial para mantener buenos resultados luego del trasplante. En la actualidad existen dos métodos principales, la perfusión hipotérmica asistida por una máquina y la preservación en frío estático. El objetivo principal de este resumen es comparar ambos sistemas de preservación. MÉTODOS: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos 10 revisiones sistemáticas que en conjunto incluyeron 34 estudios primarios, de los cuales 13 corresponden a ensayos aleatorizados. Concluimos que la preservación mediante perfusión hipotérmica de máquina probablemente disminuye el riesgo de retraso en el funcionamiento del injerto y podría llevar a un leve aumento en la sobrevida del injerto. Sin embargo, no existen diferencias en la sobrevida del paciente entre ambos métodos.

INTRODUCTION: The adequate preservation of the allograft prior to kidney transplant is key for a good outcome after transplantation. Currently, there are two main methods: hypothermic machine perfusion and static cold preservation. The main objective of this summary is to compare both preservation systems. METHODS: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified 10 systematic reviews including 34 primary studies, of which 13 were randomized trials. We concluded preservation by hypothermic machine perfusion probably decreases the risk of delayed graft function and could lead to a slight increase in graft survival. However, there are no differences in patient survival between the two methods.

Effects of Triptolide on Biological Activity of Sciatic Nerve in Cold Preservation and Nerve Regeneration after Allogeneic Transplantation in Rats / 中国康复理论与实践

@#Objective To investigate the effects of triptolide (T10) on biological activity of sciatic nerve in cold preservation and nerve regeneration after allogeneic transplantation. Methods Cell Counting Kit-8 (CCK-8) was used to test the proliferation of SCs in logarithmic phase in 1×10-6 mol/L, 1×10-7 mol/L, 1×10-8 mol/L and 1×10-9 mol/L of T10 solution. The sciatic nerves from Sprague-Dawley rats were pretreated in 0 mol/L, 1×10-6 mol/L, 1×10-7 mol/L, 1×10-8 mol/L and 1×10-9 mol/L of T10 solution at 4 ℃ or 37 ℃ for 24 hours (n = 6). The expression of nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) was detected with Western blotting. Other sciatic nerve fragments were randomly divided into fresh nerve group (group A, n = 30), DMEM preservation group (group B, n = 30), T10 preservation group (group C, n = 30), T10 pretreatment DMEM preservation group (group D, n = 30) and T10 pretreatment T10 preservation (group E, n = 30), and were stored under 4 ℃ for four weeks. Calcein-AM/PI double staining laser confocal microscope and flow cytometry were used to detect the living cells and dead cells. The expression of the major histocompatibility complex (MHC)-I, MHC-II and intercellular cell adhesion molecule-1 (ICAM-1) was detected with Western blotting. The corresponding sciatic nerves were used to repaire 10 mm defects in Wistar rats (named groups A', B', C', D' and E'), and fresh sciatic nerve from Wistar rats were also used to do it (group F'). Compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) were tested 16 weeks after transplantation, and then the grafts were observed for the nerve regeneration. Results SCs proliferated as the controls in the T10 solution with a concentration of 1×10-9 to 1×10-7 mol/L (P > 0.05). The expression of all the neurotrophic factors was more under 37 ℃ than under 4 ℃ in all the concentrations of T10 solution, and it was the most in the concentration of 1×10-8 mol/L whenever under 37 ℃ or 4 ℃ (P < 0.05). After four weeks of cold preservation, compared with groups B, C and D, the living nerve cells were the most in group E, and the expression of MHC-I, MHC-II and ICAM-1 was the least (P < 0.05). CMAP, MNCV and the never regeneration were better in group E' than in groups A', B', C' and D' (P < 0.05). A large number of myelinated nerve fibers were observed in groups E' and F', uniformity in size, wide distribution, and with myelin sheath, compared with those in groups A', B', C' and D'. Conclusion A certain concentration of T10 can induce the sciatic nerve of rats to express neurotrophic factor in vitro, which can improve the biological activity of cold preservation nerves, reduce the immunogenicity, and promote the regeneration of recipient nerve after allogeneic transplantation. It is even better to be pretreated with T10 before cold preservation.