Liver Perfusion Research Articles

Comparison of in-gel and in-solution proteolysis in the proteome profiling of organ perfusion solutions

PurposeThe organ perfusion solution (perfusate), collected at clinically and temporally significant stages of the organ preservation and transplantation process, provides a valuable insight into the biological status of an organ over time and prior to reperfusion (transplantation) in the recipient. The objective of this study was to assess two bottom-up proteomics workflows for the extraction of tryptic peptides from the perfusate.Experimental designTwo different kinds of perfusate samples from kidney and liver trials were profiled using liquid chromatography–mass spectrometry (LC-MS/MS). The preparation of clean peptide mixtures for downstream analysis was performed considering different aspects of sample preparation; protein estimation, enrichment, in-gel and urea-based in-solution digestion.ResultsIn-solution digestion of perfusate allowed identification of the highest number of peptides and proteins with greater sequence coverage and higher confidence data in kidney and liver perfusate. Key pathways identified by gene ontology analysis included complement, coagulation and antioxidant pathways, and a number of biomarkers previously linked to ischemia-reperfusion injury were also observed in perfusate.ConclusionsThis study showed that in-solution digestion is a more efficient method for LC-MS/MS analysis of kidney and liver organ perfusion solutions. This method is also quicker and easier than in-gel digestion, allowing for greater sample throughput, with fewer opportunities for experimental error or peptide loss.

Afferent venous perfusion of fetal liver: umbilical and portal blood-flow volumes in fetuses born small-for-gestational age.

To quantify the dynamic changes in the afferent venous flow volume of the liver in low-risk pregnancies with fetuses born small-for-gestational age. This was a prospective study of low-risk singleton pregnancies with estimated fetal weight (EFW) and birth weight ≤ 10th centile attending for a routine second- or third-trimester ultrasound examination. Their umbilical and portal blood-flow volumes were compared with those of a control group of fetuses born appropriate-for-gestational age from which normal reference ranges were constructed. Absolute and Z-score differences between the groups were assessed. In total, 133 fetuses were included in the study group and 362 in the control group. The mean umbilical blood-flow volume in the study group, both absolute and normalized per kg of EFW, was below that of the appropriate-for-gestational-age fetuses for most of the period of pregnancy studied (overall mean Z-score, -0.82 and -0.84, respectively). In contrast, the mean portal blood-flow volume, per kg of EFW, showed the opposite trend (overall mean Z-score, +0.86), reaching its maximum level (+1.43) in the late third trimester. This resulted in a steep decrease in the mean placental-to-portal-blood-flow volume ratio, from 14.4 at 24 weeks of gestation (above the 60th centile) to 4.7 at 38 weeks of gestation (15th centile), corresponding to Z-scores of +0.4 and -1.02, respectively. In fetuses born small-for-gestational age, the ratio of blood-flow volume in the umbilical vein to that in the portal vein decreases consistently during pregnancy, and to a greater extent compared with those born appropriate-for-gestational age, reaching a lower nadir in the third trimester. This additional redistribution of liver perfusion affects negatively fetal growth even in low-risk pregnancy, and should be taken into account when planning delivery. We suggest considering liver venous perfusion as an ancillary tool for monitoring small-for-gestational-age pregnancies. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Normothermic Machine-perfused Human Donor Livers Produce Functional Hemostatic Proteins.

Normothermic machine perfusion (NMP) is used for the viability assessment of high-risk donor livers before transplantation. The production of hemostatic proteins is one of the major synthetic functions of the liver. The objective of this study was to measure the concentration and functionality of hemostatic proteins concentration in the NMP perfusate of human donor livers. Thirty-six livers that underwent NMP for viability assessment were included in this study. Perfusate samples taken during NMP (start, 150 min, and 300 min) were used for the measurement of antigen and activity levels of hemostatic proteins (factors II, VII, and X; fibrinogen; plasminogen; antithrombin; tissue plasminogen activator; von Willebrand factor; and proteins induced by vitamin K absence). The antigen levels were correlated with hepatocellular function according to previously proposed individual hepatocellular viability criteria: lactate clearance and perfusate pH. Antigen levels of hemostatic proteins reached subphysiological levels in the NMP perfusate. Hemostatic proteins that were produced during NMP were at least partially active. All livers produced all hemostatic proteins tested within 150 min of NMP. Hemostatic protein concentrations did not significantly correlate with perfusate lactate and perfusate pH after 150 min of NMP. All livers produce functional hemostatic proteins during NMP. The generation of a functional hemostatic system in NMP perfusate confirms the need for adequate anticoagulation of the perfusate to avoid generation of (micro)thrombi that may harm the graft.

Hepatobiliary disease after bone marrow transplant: A cross-sectional study of 377 patients.

Bone marrow transplantation (BMT) is a standard treatment for several haematologic conditions. Following BMT, patients may develop hepatobiliary complications that impact morbidity and mortality. The differential diagnosis may include drug-induced liver injury (DILI), sepsis-associated liver injury (SALI), sinusoidal obstruction syndrome (SOS), graft-versus-host disease (GVHD), viral hepatitis, ischaemic hepatitis, and fulminant hepatitis. To evaluate the frequency, clinical characteristics, and outcomes of patients with hepatobiliary alterations associated with BMT in a tertiary referral centre. This was a cross-sectional study with data collected from the medical records of patients undergoing BMT between January 2017 and June 2022. We diagnosed hepatobiliary complications based on established criteria. We included 377 patients; 55.7% had hepatobiliary complications. Female gender, pre-BMT hepatobiliary alteration, and haploidentical allogeneic transplantation were associated with increased risk with odds ratios (OR) of 1.8 (p = 0.005), 1.72 (p = 0.013) and 3.25 (p = 0.003), respectively. Patients with hepatobiliary complications spent longer in the hospital than those without (27.7 × 19.3 days, respectively; p < 0.001). Among 210 patients with hepatobiliary complications, 28 died compared to 5 of 167 without complications (OR 4.98; p = 0.001). Hepatobiliary complications are frequent in patients undergoing BMT. There is a greater risk of their occurrence in women, people with pre-BMT liver alterations, and in haploidentical transplants. The occurrence of these complications increases the length of stay and is associated with a higher risk of death.

Hepatic Glucose Production, Ureagenesis, and Lipolysis Quantified using the Perfused Mouse Liver Model.

The liver has numerous functions, including nutrient metabolism. In contrast to other in vitro and in vivo models of liver research, the isolated perfused liver allows the study of liver biology and metabolism in the whole liver with an intact hepatic architecture, separated from the influence of extra-hepatic factors. Liver perfusions were originally developed for rats, but the method has been adapted to mice as well. Here we describe a protocol for in situ perfusion of the mouse liver. The liver is perfused antegradely through the portal vein with oxygenated Krebs-Henseleit bicarbonate buffer, and the output is collected from the suprahepatic inferior vena cava with clamping of the infrahepatic inferior vena cava to close the circuit. Using this method, the direct hepatic effects of a test compound can be evaluated with a detailed time resolution. Liver function and viability are stable for at least 3 h, allowing the inclusion of internal controls in the same experiment. The experimental possibilities using this model are numerous and may infer insight into liver physiology and liver diseases.

Peripheral insulin resistance is early, progressive, and correlated with cachexia in Walker-256 tumor-bearing rats.

Insulin (INS) resistance is often found in cancer-bearing, but its correlation with cachexia development is not completely established. This study investigated the temporal sequence of the development of INS resistance and cachexia to establish the relationship between these factors in Walker-256 tumor-bearing rats (TBrats). INS hepatic sensitivity and INS resistance-inducing factors, such as free fatty acids (FFA) and tumor necrosis factor-α (TNF-α), were also evaluated. Studies were carried out on Days 2, 5, 8, and/or 12 after inoculation of tumor cells in rats. The peripheral INS sensitivity was assessed by theINS tolerance testand the INS hepatic sensitivity in in situ liver perfusion. TBrats with 5, 8, and 12 days of tumor, but not 2 days, showed decreased peripheral INS sensitivity (INS resistance), retroperitoneal fat, and body weight, compared to healthy rats, which were more pronounced on Day 12. Gastrocnemius muscle wasting was observed only on Day 12 of tumor. The peripheral INS resistance was significantly correlated (r = -.81) with weight loss. Liver INS sensitivity of TBrats with 2 and 5 days of tumor was unchanged, compared to healthy rats. TBrats with 12 days of tumor showed increased plasma FFA and increased TNF-α in retroperitoneal fat and liver, but not in the gastrocnemius, compared to healthy rats. In conclusion, peripheral INS resistance is early, starts along with fat and weight loss and before muscle wasting, progressive, and correlated with cachexia, suggesting that it may play an important role in the pathogenesis of the cachectic process in TBrats. Therefore, early correction of INS resistance may be a therapeutic approach to prevent and treat cancer cachexia.

Liver Fibrosis Scores Are Associated With Resting and Exercise Fontan and Pulmonary Artery Wedge Pressures: Insights Into FALD.

Alterations in liver perfusion and venous hypertension have been implicated in the pathophysiology of Fontan-associated liver disease (FALD). However, the correlation between exercise hemodynamics and markers of FALD have not been studied. We performed a retrospective review of 32 consecutive adults undergoing exercise catheterisation at the Mayo Clinic, Minnesota. Invasive hemodynamics were correlated with aspartate transaminase to platelet ratio index (APRI) and the Fibrosis-4 (Fib-4) score, well validated surrogates of liver fibrosis. The mean age was 30.9 ± 7 years. The mean APRI was 0.5±0.2 and the mean Fib-4 score 1.3 ± 0.8. Fib-4 scores correlated with spleen size on abdominal imaging (r= 0.40; P= 0.03). Resting Fontan pressure was 13.9 ± 3.9 mm Hg and pulmonary artery wedge pressure (PAWP) 10.0 ± 3.5 mm Hg. At peak exercise (69.4 ± 23.2 W), Fontan pressures increased to 26.5 ± 6.2 mm Hg and PAWP to 22.4±7.1 mm Hg. APRI and Fib-4 score were directly related to Fontan pressure and PAWP at rest and during exercise, and inversely related to exercise arterial O2 saturation. Fib-4 inversely correlated with O2 delivery indices. Similarly, when categorising patients according to high APRI (>0.5 vs ≤ 0.5) or Fib-4 score (≥ 1.45 vs < 1.45) according to previously proposed cutoffs for diagnosis of liver fibrosis, those with elevated scores had higher resting and exercise Fontan and PAWP pressure with lower O2 arterial saturation. ARPI and Fib-4 score correlated with resting and exercise Fontan pressure and PAWP. In addition, Fib-4 scores were inversely related to O2 delivery indices. These findings support a role played by hepatic venous hypertension and reduced O2 supply in patients with FALD.

PB0565 Long-Term ex-situ Normothermic Machine Perfusion of Human Livers Provides a Platform to Study (Patho)Physiology and Production of Hemostatic Proteins

PB0565 Long-Term ex-situ Normothermic Machine Perfusion of Human Livers Provides a Platform to Study (Patho)Physiology and Production of Hemostatic Proteins

Long-term normothermic liver perfusion.

Long-term normothermic liver perfusion.

Ingestion of minoxidil associated with elevated transaminases in the absence of ischemic hepatitis

Minoxidil is a direct-acting vasodilator that induces relaxation of the vascular endothelium, and historically, it has been used as an antihypertensive agent. It caused hypertrichosis, resulting in its typical use today as an alopecia treatment. Toxicity is characterized by hypotension and tachycardia, often requiring treatment with α-adrenergic agonists. A previously healthy 18-year-old woman presented to the emergency department three hours after ingesting 60 mL of 5% W/V topical minoxidil solution. Initial vitals included sinus tachycardia at 117 beats per minute and a blood pressure of 92/44 mmHg. Laboratory analyses performed three hours post-ingestion revealed elevated aspartate and alanine aminotransferases (224 and 384 IU/L, respectively). Acetaminophen and ethanol concentrations were undetectable. Isotonic crystalloid, N-acetylcysteine, phenylephrine, and midodrine were administered. She developed pulmonary edema, requiring diuresis and supplemental oxygen via a nasal cannula. She was discharged 108 hours post-ingestion after a full recovery. Minoxidil toxicity may be an uncommon etiology of abnormal transaminase concentrations.

Enhancing generation efficiency of liver organoids in a collagen scaffold using human chemically derived hepatic progenitors.

Liver organoids have emerged as a powerful tool for studying liver biology and disease and for developing new therapies and regenerative medicine approaches. For organoid culture, Matrigel, a type of extracellular matrix, is the most commonly used material. However, Matrigel cannot be used for clinical applications due to the presence of unknown proteins that can cause immune rejection, batch-to-batch variability, and angiogenesis. To obtain human primary hepatocytes (hPHs), we performed 2 steps collagenase liver perfusion protocol. We treated three small molecules cocktails (A83-01, CHIR99021, and HGF) for reprogramming the hPHs into human chemically derived hepatic progenitors (hCdHs) and used hCdHs to generate liver organoids. In this study, we report the generation of liver organoids in a collagen scaffold using hCdHs. In comparison with adult liver (or primary hepatocyte)-derived organoids with collagen scaffold (hALO_C), hCdH-derived organoids in a collagen scaffold (hCdHO_C) showed a 10-fold increase in organoid generation efficiency with higher expression of liver- or liver progenitor-specific markers. Moreover, we demonstrated that hCdHO_C could differentiate into hepatic organoids (hCdHO_C_DM), indicating the potential of these organoids as a platform for drug screening. Overall, our study highlights the potential of hCdHO_C as a tool for liver research and presents a new approach for generating liver organoids using hCdHs with a collagen scaffold.

Advancing Perfusion Models: Dual-Vessel Ex Vivo Rat Liver Perfusion Based on a Clinical Setup.

Normothermic ex vivo liver machine perfusion (NEVLP) has been developed to address the increasing organ shortage in liver transplantation, through optimal preservation, assessment, and conditioning of grafts from extended criteria donors. There remains a need to establish simple and standardized animal models that simulate clinical NEVLP to test novel therapies. Liver grafts from 36 Sprague-Dawley rats were perfused for 6 h in a dual-vessel NEVLP system with a Dulbecco's modified Eagles medium-based perfusate supplemented with rat plasma and erythrocytes. Varying doses of the clinically used vasodilator epoprostenol, Kupffer cell inhibitor glycine, and a Steen™-based perfusate were assessed. Perfusion pressures and bile production were recorded, and perfusate was analyzed for transaminase secretion. Tissue samples were evaluated histologically, and levels of cytokines and 8-Isoprostane were measured. Increasing levels of epoprostenol and the addition of glycine resulted in a stepwise decrease of transaminase secretion and improved bile production. Steen further decreased transaminase release and interleukin 1 beta levels. Liver grafts perfused with the optimized Steen-based protocol exhibited lowest levels of oxidative stress and best-preserved liver integrity. In conclusion, epoprostenol seemed to ameliorate liver function and prevent cellular damage beyond its vasodilatory effect, with glycine acting synergistically. The anti-inflammatory and antioxidative properties of Steen further improved the outcome of perfusion. Our rodent NEVLP system may be used to rapidly test new agents for the pharmacologic conditioning of livers and help translate findings from bench-to-bedside.

Prolonged warm ischemia time increases mitogen-activated protein kinase activity and decreases perfusate cytokine levels in ex vivo rat liver machine perfusion.

Machine perfusion is increasingly being utilized in liver transplantation in lieu of traditional cold static organ preservation. Nevertheless, better understanding of the molecular mechanisms underlying the ischemia-reperfusion injury (IRI) during ex vivo perfusion is necessary to improve the viability of liver grafts after transplantation using machine perfusion technology. Since key cellular signaling pathways involved in hepatic IRI may allow a chance for designing a promising approach to improve the clinical outcomes from this technology, we determined how warm ischemia time (WIT) during procurement affects the activity of mitogen-activated protein kinase (MAPK) and perfusate concentration of cytokines in an ex vivo rat liver machine perfusion model. Male Sprague-Dawley rats underwent in situ hepatic ischemia with varying WIT (0, 10, 20, 30 min, n = 5 each), and subsequently 3 h of cold ischemia time and 2 h of machine perfusion prior to determining the degree of MAPK activation-phosphorylation and cytokine concentration in liver tissue and perfusates, respectively. Our data revealed a strong correlation between incremental WIT and a series of liver injury markers, and that prolonged WIT increases ERK1/2 and p54 JNK phosphorylation during machine perfusion. Notably, specific cytokine levels (MCP-1, MIP-2, GRO/KC, IL-10, and IL-5) were inversely correlated with the phosphorylation levels of ERK1/2, p38 MAPK, and p46/p54 JNK. These results suggest that MAPK activation, specifically ERK1/2 and p54 JNK phosphorylation, have potential as a biomarker for hepatic IRI pathophysiology during machine perfusion. Elucidation of their functional significance may lead to designing a novel strategy to increase the clinical benefit of machine perfusion.

Comparative Study Evaluating the Effect of the Administration of Vitamin K1 versus Placebo on Vascular Calcification in Haemodialysis Patients

Abstract Background Cardiovascular calcification is a risk factor and contributor to morbidity and mortality in End stage kidney disease patients. Patients with chronic kidney disease develop accelerated calcification of the intima, media, heart valves and myocardium as well as the rare condition of calcific uremic arteriolopathy (calciphylaxis). Pathomechanistically, Cardiovascular calcification is most likely due to an imbalance of promoters (e.g. Calcium and phosphate) and inhibitors (e.g. fetuin-A and matrix Gla protein). Objective to study the effect of oral vitamin k1 on serum Matrix gla protein in patients on maintenance hemodialysis and to study its effect as an important marker of vascular calcification. Patients and Methods This Placebo Controlled clinical trial was conducted for 3 months on 80 adult ESRD patients on regular Hemodialysis recruited from Ain shams university Hospitals hemodialysis unit, their age ranged from 18 to 75 years each participant signed informed consent classified into two groups, with the study group containing 40 patients who received Vitamin K1 therapy 5 mg every other day for three months duration and the control placebo group containing 40 patients who received Placebo every other day for three months duration. Results There was no statistically significant difference between the two groups according to their risk factors regarding smoking, HTN, HCV, DM, and ISHD. In this clinical trial only 29 % of patients were diabetic, but their diabetes was well controlled and there was no significant difference between groups regarding incidence of diabetes. There was no significant difference between groups regarding vascular access (AVF, Double lumen tunneled dialysis catheter) and duration of dialysis (P &amp;gt; 0.05). The current study showed that vitamin k1 therapy resulted in no significant effect in comparison to the placebo group on calcium, phosphorus, calcium-phosphorus product and (P = 0.435), (P = 0.142), (P = 0.191) respectively. Age has non-significant effect on MGP level neither in the study group (P = 0.636) before vitamin k1 therapy nor in the placebo group (P = 0.841) and after vitamin k1 therapy in study group (P = 0.605) and placebo group (P = 0.332). Conclusion Different risk factors including Hypertension, Diabetes Mellitus, Smoking, Heart failure, Ischemic heart disease and hepatitis c virus has no significant effect on serum MGP levels neither before nor after therapy in both study and placebo groups.

An adapted liver perfusion in a shark species, Squalus suckleyi: investigation of energy mobilization.

The liver is an essential energy storage organ in vertebrates. In teleosts and elasmobranchs, previous studies examining hepatic energy balance have used isolated hepatocytes. Although these studies have been informative, the high-fat content in the elasmobranch liver limits isolation of hepatocytes and therefore the utility of this method to understand hepatic metabolic processes. In the present study, we developed an in situ liver perfusion in the North Pacific spiny dogfish Squalus suckleyi. Perfusions were conducted by cannulating the hepatic portal vein (inflowing cannulation) and the sinus venosus through the heart (outflowing cannulation). Changes in major elasmobranch metabolites (glucose and 3-hydroxybutarate [3-HB]) were determined by the arterial (inflow)-venous (outflow) difference in metabolite concentration. Liver preparations were considered viable due to consistent oxygen consumption over 3 h and the maintenance of predictable vasoconstriction following administration of homologous 10-7 M angiotensin II (ANG II). Removal and reintroduction from the perfusate of metabolites showed endogenous 3-HB production in the isolated perfused livers but did not affect glucose balance. However, the arterial-venous difference of both metabolites did not change following perfusion with heterologous insulin and homologous glucagon, which may be due to the glucose intolerant nature of elasmobranchs. Ultimately, we show the viability of this perfusion for the investigation of hepatic energy mobilization in sharks.NEW & NOTEWORTHY We describe a viable liver perfusion in a shark species for the first time as determined by oxygen consumption and hormone-mediated changes in hemodynamics (angiotensin II, ANG II). In addition, removal of major energy metabolites confirms hepatic ketone [3-hydroxybutyrate (3-HB)] production by an elasmobranch liver. Perfusion with heterologous insulin and homologous glucagon did not cause changes in glucose balance, however, possibly demonstrating differences in glucose metabolism in this taxon as compared with more derived vertebrates.

SP3.6 Does a novel preservation solution improve organ performance in an ex-vivo perfusion of porcine liver?

Abstract Aims This project aims to compare LS-A (Leeds solution for abdomen) to a gold standard solution, IGL-1 (Institute George-Lopez solution) at clinically acceptable CIT (Cold ischaemic time) in a DCD (Donation after cardiac death) model of porcine liver transplant. An ex-vivo Perfusion device will then provide normothermic machine perfusion to simulate the immediate post-transplant stage. Methods DCD livers retrieved from landrace pigs, were preserved at 4-hours CIT in LS-A or IGL-1. They were re-perfused on a normothermic machine perfusion device, using autologous blood as a perfusate. Biochemical analysis was performed hourly for various markers of tissue and hepatocyte damage. Results Livers stored in LS-A (n=6) and IGL-1 (n=6) have no significant differences when compared for ALT, AST, ALP, LDH and glucose. Perfusate lactate was significantly lower in the LS-A group (p=0.008) as was the perfusate potassium(p=0.001) across the perfusion period. Conclusions Analysis has shown significantly lower lactate and potassium in LS-A preserved livers, in DCD retrieval, with 4-hours CIT. There are no other observed significant differences between LS-A and IGL-1 when comparing liver function tests and LDH production. This suggests better tissue preservation with LS-A in the setting of very high risk donor livers. The next stage of the project will look at LS-A vs IGL-1 in an extended preservation period (&amp;gt;14 hours) in a DBD (Donation after brainstem death) model.

Effectiveness of machine perfusion in liver transplantation: A meta-analysis of randomized controlled trials

BackgroundIn contemporary transplantation research, the utilization of machine perfusion to facilitate the perfusion, preservation, evaluation, and repair of donor livers has garnered considerable attention.In an effort to comprehensively assess the clinical outcomes of liver transplantation procedures incorporating machine perfusion, a meta-analysis of published randomized controlled trials (RCTs) was undertaken. MethodsThe relevant literature was obtained from PubMed, EMBASE, Web of Science, and other databases up until December 2022. Subsequently, the authors extracted the requisite data, conducted a meta-analysis, and arrived at a conclusion based on the findings derived from the analysis. ResultsA total of seven high-quality prospective RCTs, comprising 917 patients, were included in the analysis. Machine perfusion demonstrated significant superiority over cold storage in reducing the incidence of major postoperative complications (RR 0.55, 95% CI 0.42 to 0.73; p < 0.0001) and early allograft dysfunction (RR 0.52, 95% CI 0.41 to 0.67; p < 0.00001). Notably, postoperative aspartate aminotransferase peak, bilirubin levels, and post-reperfusion lactate were also found to decrease. However, no statistically significant differences were observed for other outcomes. Hypothermic oxygenation machine perfusion demonstrated a lower frequency of re-transplantation (RR 0.29, 95% CI 0.10 to 0.86; p = 0.03), rejection (RR 0.55, 95% CI 0.32 to 0.95; p = 0.03), and resulted in shorter hospital stays (Std, MD -0.30, 95% CI -0.52 to -0.07; p = 0.009). ConclusionsThe application of machine perfusion can yield significant improvements in the outcomes of liver transplantation.

24-hour normothermic machine perfusion of discarded human liver grafts: Case series single-center study

BackgroundThe persistent shortage of liver allografts contributes to significant waitlist mortality. Normothermic machine perfusion (NMP) has the potential to extend viability and allow liver function evaluation in discarded organs. The main aim of the study was to evaluate the possibility for extended preservation and the potential recovery of non-usable human livers utilizing NMP. Methods6 high-risk human liver grafts that were discarded after national allocation underwent normothermic liver preservation for an extended period of 24 h. Transmedics Organ Care System™ liver perfusion device was used to preserve a donor liver in a functioning, near physiologic state. Parameters of biochemical and synthetic liver function were collected periodically and subsequently analyzed. Liver parenchyma and bile duct biopsies were obtained pre- and 24 h post-NMP. Results4/6 (67%) grafts were DCDs with a median age of 54 (IQR: 42–61) years and median CIT of 262 (IQR: 209–1024) minutes. 5/6 (83%) livers produced a median of 75 ml of bile (Range 55–100) after 24 h of NMP. Lactate dropped to normal levels (<2 mmol/L) for all livers after around 4 h on NMP. The overall cellular architecture, lobular steatosis and necrosis grades were preserved after extended NMP. Biopsies showed improvement of liver parenchyma architecture with reduced inflammation for 2/6 (33%) at the end of the perfusion. ConclusionProlonged NMP for discarded liver grafts can be safely maintained on NMP and may identify certain grafts that are suitable for transplantation. Further studies utilizing NMP with subsequent transplantation would validate this strategy, as well as existing viability markers.

Long-term ex situ normothermic perfusion of human split livers for more than 1 week

Current machine perfusion technology permits livers to be preserved ex situ for short periods to assess viability prior to transplant. Long-term normothermic perfusion of livers is an emerging field with tremendous potential for the assessment, recovery, and modification of organs. In this study, we aimed to develop a long-term model of ex situ perfusion including a surgical split and simultaneous perfusion of both partial organs. Human livers declined for transplantation were perfused using a red blood cell-based perfusate under normothermic conditions (36 °C) and then split and simultaneously perfused on separate machines. Ten human livers were split, resulting in 20 partial livers. The median ex situ viability was 125 h, and the median ex situ survival was 165 h. Long-term survival was demonstrated by lactate clearance, bile production, Factor-V production, and storage of adenosine triphosphate. Here, we report the long-term ex situ perfusion of human livers and demonstrate the ability to split and perfuse these organs using a standardised protocol.

Effect of Kinins on the Hepatic Oxidative Stress in Mice Treated with a Methionine-Choline Deficient Diet.

Non-alcoholic fatty liver is the leading cause of hepatic disease worldwide and ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) due to cell injury, oxidative stress, and apoptosis. The kinins' role in the liver has been studied in experimental fibrosis, partial hepatectomy, and ischemia-reperfusion and is related to cell death and regeneration. We investigated its role in experimental NASH induced by a methionine-choline deficient diet for 4 weeks. After that, liver perfusion was performed, and bradykinin (BK) or des-Arg9-BK was infused. Cell death was evaluated by cathepsin-B and caspase-3 activity and oxidative stress by catalase (CAT), glutathione S-transferase, and superoxide dismutase (SOD) activities, as well as malondialdehyde and carbonylated proteins. In control livers, DABK increased CAT activity, which was reversed by antagonist DALBK. In the NASH group, kinins tend to decrease antioxidant activity, with SOD activity being significantly reduced by BK and DABK. Malondialdehyde levels increased in all NASH groups, but carbonylated protein did not. DABK significantly decreased cathepsin-B in the NASH group, while caspase-3 was increased by BK in control animals. Our results suggest that B1R and/or B2R activation did not induce oxidative stress but affected the antioxidant system, reducing SOD in the NASH group.