High serum Aspartate transaminase levels on day 3 postliver transplantation correlates with graft and patient survival and would be a valid surrogate for outcome in liver transplantation clinical trials

Effects of Dietary Microbial Muramidase on the Growth, Liver Histoarchitecture, Antioxidant Status, and Immunoexpression of Pro-Inflammatory Cytokines in Broiler Chickens

The impact of microbial muramidase (MMUR) addition to broiler chicken rations was evaluated through growth parameters, liver histoarchitecture, antioxidant status, biochemical analysis, and expression of pro-inflammatory cytokines for 35 days. Four hundred three-day-old chicks (97.68 ± 0.59 g) were distributed to four distinct groups with ten duplicates each (100 chicks/group) consisting of: group 1 (G1): a basal diet without MMUR (control group); G2: a basal diet + 200 mg MMUR kg-1 G3: a basal diet + 400 mg MMUR kg-1; and G4: a basal diet + 600 mg MMUR kg-1. The results showed that the final body weight and total weight gain were increased (p = 0.015) in birds fed with diets supplemented with MMUR at 600 mg kg-1. The feed conversion ratio (FCR) was improved in all treatment groups compared with the control group. Birds fed with a diet supplemented with 600 mg MMUR kg-1 showed the highest body weight gain and improved FCR. The values of thyroxin hormones and growth hormones were increased in all MMUR-supplemented groups. Dietary MMUR increased the activities of antioxidant enzymes (total antioxidant activity, catalase, and superoxide dismutase) and decreased the activity of malondialdehyde (p < 0.05). In addition, it increased the values of interleukin 1 beta and interferon-gamma compared with the control group. Furthermore, dietary MMUR increased the expression of transforming growth factor-beta immunostaining in the liver and spleen tissues. Our results show that supplementing broilers' diets with 600 mg MMUR kg-1 could enhance the chicken growth rate and improve their antioxidant, inflammatory, and anti-inflammatory responses.

Hematology profile, digestive enzymes, thyroid hormones, productivity, and nitrogen balance of growing male rabbits supplemented with exogenous dietary lysozyme

In a simple randomized design trial, 420 growing male V-Line rabbits were randomly distributed into four groups to investigate the impact of exogenous dietary lysozyme on some physiological and nutritional parameters of male growing rabbits supplemented with exogenous dietary lysozyme. The witness group received a basal diet without exogenous dietary lysozyme (LYZ0), while the exogenous dietary lysozyme groups received 50, 100 and 150 mg/kg of basal diet (Groups; LYZ50, LYZ100 and LYZ150), respectively. The results showed significantly increased in blood cell count, hemoglobin concentration, total white blood cell, lipase, protease, amylase, total protein, triiodothyronine and thyroxine levels, while thyroid stimulating hormone levels significantly lessened in rabbits received LYZ. The LYZ- rabbit diets improved total digestible nutrient, digestible crude protein, and digestible energy values, with the LYZ100 group outperforming the others. LYZ-treated rabbits had significantly higher nitrogen intake, digestible nitrogen, and nitrogen balance than the witness group. The lysozyme in a rabbit's diet is taking on a new role as a digestive enzyme, enhancement thyroid hormones, as well as improvement hematology, daily protein efficiency ratio, daily performance index, hot carcass, total edible parts, nutritional value, and nitrogen balance, with decreasing the daily caloric conversion ratio and total non-edible parts.

Exploring the effects of lysozyme dietary supplementation on laying hens: performance, egg quality, and immune response

An experiment was conducted to evaluate the dietary supplementation with lysozyme's impacts on laying performance, egg quality, biochemical analysis, body immunity, and intestinal morphology. A total of 720 Jingfen No. 1 laying hens (53 weeks old) were randomly assigned into five groups, with six replicates in each group and 24 hens per replicate. The basal diet was administered to the laying hens in the control group, and it was supplemented with 100, 200, 300, or 400 mg/kg of lysozyme (purity of 10% and an enzyme activity of 3,110 U/mg) for other groups. The preliminary observation of the laying rate lasted for 4 weeks, and the experimental period lasted for 8 weeks. The findings demonstrated that lysozyme might enhance production performance by lowering the rate of sand-shelled eggs (P < 0.05), particularly 200 and 300 mg/kg compared with the control group. Lysozyme did not show any negative effect on egg quality or the health of laying hens (P > 0.05). Lysozyme administration in the diet could improve intestinal morphology, immune efficiency, and nutritional digestibility in laying hens when compared with the control group (P < 0.05). These observations showed that lysozyme is safe to use as a feed supplement for the production of laying hens. Dietary supplementation with 200 to 300 mg/kg lysozyme should be suggested to farmers as a proper level of feed additive in laying hens breeding.

Delivering siRNA Compounds During HOPE to Modulate Organ Function: A Proof-of-Concept Study in a Rat Liver Transplant Model

BACKGROUND

Apoptosis contributes to the severity of ischemia-reperfusion injury (IRI), limiting the use of extended criteria donors in liver transplantation (LT). Machine perfusion has been proposed as a platform to administer specific therapies to improve graft function. Alternatively, the inhibition of genes associated with apoptosis during machine perfusion could alleviate IRI post-LT. The aim of the study was to investigate whether inhibition of an apoptosis-associated gene (FAS) using a small interfering RNA (siRNA) approach could alleviate IRI in a rat LT model.

METHODS

In 2 different experimental protocols, FASsiRNA (500 µg) was administered to rat donors 2 h before organ procurement, followed by 22 h of static cold storage, (SCS) or was added to the perfusate during 1 h of ex situ hypothermic oxygenated perfusion (HOPE) to livers previously preserved for 4 h in SCS.

RESULTS

Transaminase levels were significantly lower in the SCS-FASsiRNA group at 24 h post-LT. Proinflammatory cytokines (interleukin-2, C-X-C motif chemokine 10, tumor necrosis factor alpha, and interferon gamma) were significantly decreased in the SCS-FASsiRNA group, whereas the interleukin-10 anti-inflammatory cytokine was significantly increased in the HOPE-FASsiRNA group. Liver absorption of FASsiRNA after HOPE session was demonstrated by confocal microscopy; however, no statistically significant differences on the apoptotic index, necrosis levels, and FAS protein transcription between treated and untreated groups were observed.

CONCLUSIONS

FAS inhibition through siRNA therapy decreases the severity of IRI after LT in a SCS protocol; however the association of siRNA therapy with a HOPE perfusion model is very challenging. Future studies using better designed siRNA compounds and appropriate doses are required to prove the siRNA therapy effectiveness during liver HOPE liver perfusion.

The Effect of Exogenous Lysozyme Supplementation on Growth Performance, Caecal Fermentation and Microbiota, and Blood Constituents in Growing Rabbits

The effects of exogenous lysozyme supplementation (LYZ) on growth performance, caecal fermentation and microbiota, and blood characteristics were investigated in growing rabbits. A total of 420 growing male V-Line rabbits (30 d old; weighing 528 ± 16 g) were randomly divided into four groups of 105 rabbits each, and monitored for 42 days. Experimental groups included a control group (LYZ0) fed a basal diet without LYZ supplementation, and three treated groups fed the same basal diet supplemented with LYZ at 50, 100, and 150 mg/kg diet, respectively. The results showed a quadratic improvement in the final body weight, daily growth rate, FCR, and digestibility of DM, while the digestibility of OM, CP, EE, NDF, and ADF improved linearly when LYZ supplementation was increased. The dressing percentage increased quadratically when LYZ levels were increased in the rabbit diets. In rabbits fed LYZ diets, L. acidophilus counts increased linearly (p < 0.05) and L. cellobiosus, and Enterococcus sp. counts increased quadratically, whereas E. coli counts decreased. In the LYZ-supplemented groups, the caecal pH value and NH3-N concentration declined quadratically, whereas total VFA, acetic, and butyric acids increased. Total lipids decreased linearly, whilst triglycerides and cholesterol decreased quadratically with LYZ supplementation. Total antioxidant capacity, superoxide dismutase, glutathione S-transferase, and catalase increased quadratically, while malondialdehyde decreased linearly in the LYZ-supplemented groups. In conclusion, exogenous lysozyme administration improved rabbit growth performance and antioxidant status while lowering the blood lipid profile, altering the bacterial population, and regulating caecal fermentation. Therefore, LYZ up to 150 mg/kg can be used as a potential supplement in rabbit feed.

Effect of post-operative goal-directed fluid therapy (GDFT) on organ function after orthotopic liver transplantation: Secondary outcome analysis of the COLT randomised control trial

BACKGROUND

Goal-directed fluid therapy (GDFT) has been shown to reduce the complications following a variety of major surgical procedures, possibly mediated by improved organ perfusion and function. We have shown that it is feasible to randomise patients to GDFT or standard fluid management following liver transplant in the cardiac-output optimisation following liver transplantation (COLT) trial. The current study compares end organ function in patients from the COLT trial who received GDFT in comparison to those receiving standard care (SC) following liver transplant.

METHODS

Adult patients with liver cirrhosis undergoing liver transplantation were randomised to GDFT or SC for the first 12 h following surgery as detailed in a published trial protocol. GDFT protocol was based on stroke volume (SV) optimisation using 250 ml crystalloid boluses. Total fluid administration and time to extubation were recorded. Hourly SV and cardiac output (CO) readings were recorded from the non-invasive cardiac output monitoring (NICOM) device in both groups. Pulmonary function was assessed by arterial blood gas (ABG) and ventilatory parameters. Lung injury was assessed using PaO₂:FiO₂ ratios and calculated pulmonary compliance. The KDIGO score was used for determining acute kidney injury. Renal and liver graft function were assessed during the post-operative period and at 3 months and 1-year.

RESULTS

60 patients were randomised to GDFT (n = 30) or SC (n = 30). All patients completed the 12 h intervention period. GDFT group received a significantly higher total volume of fluid during the 12 h trial intervention period (GDFT 5317 (2335) vs. SC 3807 (1345) ml, p = 0.003); in particular crystalloids (GDFT 3968 (2073) vs. SC 2510 (1027) ml, p = 0.002). There was no evidence of significant difference between the groups in SV or CO during the assessment periods. Time to extubation, PaO2: FIO₂ ratios, pulmonary compliance, ventilatory or blood gas measurements were similar in both groups. There was a significant rise in serum creatinine from baseline (77 μmol/L) compared to first (87 μmol/L, p = 0.039) and second (107 μmol/L, p = 0.001) post-operative days. There was no difference between GDFT and SC in the highest KDIGO scores for the first 7 days post-LT. At 1-year follow-up, there was no difference in need for renal replacement therapy or graft function.

CONCLUSIONS

In this randomised trial of fluid therapy post liver transplant, GDFT was associated with an increased volume of crystalloids administered but did not alter early post-operative pulmonary or renal function when compared with standard care.

Machine Perfusion in Liver Transplantation: A Systematic Review and Meta-Analysis

Background

Liver transplantation (LTx) is the only treatment option for patients with end-stage liver disease. Novel organ preservation techniques such as hypothermic machine perfusion (HMP) or normothermic machine perfusion (NMP) are under investigation in order to improve organ quality from extended criteria donors and donors after circulatory death. The aim of this study was to systematically review the literature reporting LTx outcomes using NMP or HMP compared to static cold storage (SCS).

Methods

The following data were retrieved: graft primary nonfunction rate, early allograft dysfunction (EAD) rate, biliary complication rate, and 12-month graft and patient survival. A total of 15 studies were included (6 NMP and 9 HMP studies), and meta-analysis was performed only for HMP studies because NMP had considerable differences.

Results

The systematic review showed the potential of NMP to reduce graft injury and lower the liver graft discard rate. The performed quantitative analyses showed that the use of HMP reduces the rate of EAD (odds ratio [OR] 0.51; 95% confidence interval [CI] 0.34–0.76; p = 0.001; I² = 0%) and non-anastomotic biliary strictures (OR 0.34; 95% CI 0.17–0.67; p = 0.002; I² = 0%) compared to SCS.

Conclusion

Our systematic review and meta-analysis revealed that the use of HMP reduces the rate of EAD and non-anastomotic biliary strictures compared to SCS.

Ischemic Preconditioning for Liver Transplantation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

In recent decades, liver transplantation (LTx) has increased the survival and quality of life of patients with end-stage organ failure. Unfortunately, LTx is limited due to the shortage of donors. A lot of effort is put into finding new ways to reduce ischemia-reperfusion injury (IRI) in liver grafts to increase the number of suitable organs procured from expanded-criteria donors (ECD). The aim of this study was to systematically review the literature reporting LTx outcomes when using ischemic preconditioning (IPC) or remote ischemic preconditioning (RIPC) to reduce IRI in liver grafts.

Methods

A literature search was performed in the MEDLINE, Web of Science, and EMBASE databases. The following combination was used: "Liver" OR "Liver Transplantation" AND "Ischemic preconditioning" OR "occlusion" OR "clamping" OR "Pringle." The following outcome data were retrieved: the rates of graft primary nonfunction (PNF), retransplantation, graft loss, and mortality; stay in hospital and the intensive care unit; and postoperative serum liver damage parameters.

Results

The initial search retrieved 4,522 potentially relevant studies. After evaluating 17 full-text articles, a total of 9 randomized controlled trials (RCTs) were included (7 IPC and 2 RIPC studies) in the qualitative synthesis; the meta-analysis was only performed on the data from the IPC studies. RIPC studies had considerable methodological differences. The meta-analysis revealed the beneficial effect of IPC when comparing postoperative aspartate aminotransferase (AST) corresponding to a statistically lower mortality rate in the IPC group (odds ratio [OR] 0.51; 95% confidence interval [CI] 0.27-0.98; p = 0.04).

Conclusion

IPC lowers postoperative AST levels and reduces the mortality rate; however, data on the benefits of RIPC are lacking.

Serum Glycomics on Postoperative Day 7 Are Associated With Graft Loss Within 3 Months After Liver Transplantation Regardless of Early Allograft Dysfunction

BACKGROUND

Prediction of outcome after liver transplantation (LT) is limited by the lack of robust predictors of graft failure. In this prospective study, we aimed to define a serum glycomic signature in the first week after LT that is associated with graft loss at 3 mo after LT.

METHODS

Patients were included between January 1, 2011, and February 28, 2017. Glycomic analysis was performed using DNA sequencer-associated fluorophore-associated capillary electrophoresis on a serum sample 1 wk after LT. Making use of Lasso regression, an optimal glycomic signature was identified associated with 3-mo graft survival.

RESULTS

In this cohort of 131 patients, graft loss at 3 mo occurred in 14 patients (11.9%). The optimal mode, called the GlycoTransplantTest, yielded an area under the curve of 0.95 for association with graft loss at 3 mo. Using an optimized cutoff for this biomarker, sensitivity was 86% and specificity 89%. Negative predictive value was 98%. Odds ratio for graft loss at 3 mo was 70.211 (P < 0.001; 95% confidence interval, 10.876-453.231).

CONCLUSIONS

A serum glycomic signature is highly associated with graft loss at 3 mo. It could support decision making in early retransplantation.

Design, Analysis, and Pitfalls of Clinical Trials Using Ex Situ Liver Machine Perfusion: The International Liver Transplantation Society Consensus Guidelines

BACKGROUND

Recent trials in liver machine perfusion (MP) have revealed unique challenges beyond those seen in most clinical studies. Correct trial design and interpretation of data are essential to avoid drawing conclusions that may compromise patient safety and increase costs.

METHODS

The International Liver Transplantation Society, through the Special Interest Group "DCD, Preservation and Machine Perfusion," established a working group to write consensus statements and guidelines on how future clinical trials in liver perfusion should be designed, with particular focus on relevant clinical endpoints and how different techniques of liver perfusion should be compared. Protocols, abstracts, and full published papers of clinical trials using liver MP were reviewed. The use of a simplified Grading of Recommendations Assessment, Development, and Evaluation working group (GRADE) system was attempted to assess the level of evidence. The working group presented its conclusions at the International Liver Transplantation Society consensus conference "DCD, Liver Preservation, and Machine Perfusion" held in Venice, Italy, on January 31, 2020.

RESULTS

Twelve recommendations were proposed with the main conclusions that clinical trials investigating the effect of MP in liver transplantation should (1) make the protocol publicly available before the start of the trial, (2) be adequately powered, and (3) carefully consider timing of randomization in function of the primary outcome.

CONCLUSIONS

There are issues with using accepted primary outcomes of liver transplantation trials in the context of MP trials, and no ideal endpoint could be defined by the working group. The setup of an international registry was considered vital by the working group.

Biliary complications after liver transplantation: current perspectives and future strategies

Importance

Liver transplantation (LT) is a life-saving therapy for patients with end-stage liver disease and with acute liver failure, and it is associated with excellent outcomes and survival rates at 1 and 5 years. The incidence of biliary complications (BCs) after LT is reported to range from 5% to 20%, most of them occurring in the first three months, although they can occur also several years after transplantation.

Objective

The aim of this review is to summarize the available evidences on pathophysiology, risk factors, diagnosis and therapeutic management of BCs after LT.

Evidence Review

a literature review was performed of papers on this topic focusing on risk factors, classifications, diagnosis and treatment.

Findings

Principal risk factors include surgical techniques and donor's characteristics for biliary leakage and anastomotic biliary strictures and vascular alterations for non- anastomotic biliary strictures. MRCP is the gold standard both for intra- and extrahepatic BCs, while invasive cholangiography should be restricted for therapeutic uses or when MRCP is equivocal. About treatment, endoscopic techniques are the first line of treatment with success rates of 70-100%. The combined success rate of ERCP and PTBD overcome 90% of cases. Biliary leaks often resolve spontaneously, or with the positioning of a stent in ERCP for major bile leaks.

Conclusions and Relevance

BCs influence morbidity and mortality after LT, therefore further evidences are needed to identify novel possible risk factors, to understand if an immunological status that could lead to their development exists and to compare the effectiveness of innovative surgical and machine perfusion techniques.

Effect of remote ischemic preconditioning among donors and recipients following pediatric liver transplantation: A randomized clinical trial

BACKGROUND

Studies suggested that remote ischemic preconditioning (RIPC) may effectively lessen the harmful effects of ischemia reperfusion injury during organ transplantation surgery.

AIM

To investigate the protective effects of RIPC on living liver donors and recipients following pediatric liver transplantation.

METHODS

From January 2016 to January 2019 at Renji Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, 208 donors were recruited and randomly assigned to four groups: S-RIPC group (no intervention; n = 55), D-RIPC group (donors received RIPC; n = 51), R-RIPC group (recipients received RIPC, n = 51) and DR-RIPC group (both donors and recipients received RIPC; n = 51). We primarily evaluated postoperative liver function among donors and recipients and incidences of early allograft dysfunction, primary nonfunction and postoperative complications among recipients.

RESULTS

RIPC did not significantly improve alanine transaminase and aspartate aminotransferase levels among donors and recipients or decrease the incidences of early allograft dysfunction, primary nonfunction, and postoperative complications among recipients. Limited protective effects were observed, including a lower creatinine level in the D-RIPC group than in the S-RIPC group on postoperative day 0 (P < 0.05). However, no significant improvements were found in donors who received RIPC. Furthermore, RIPC had no effects on the overall survival of recipients.

CONCLUSION

The protective effects of RIPC were limited for recipients who received living liver transplantation, and no significant improvement of the prognosis was observed in recipients.

A nomogram for prediction of early allograft dysfunction in living donor liver transplantation

Liver transplantation is the treatment of choice for end-stage liver diseases. However, early allograft dysfunction (EAD) is frequently encountered and associated with graft loss or mortality after transplantation. This study aimed to establish a predictive model of EAD after living donor liver transplantation. A total of 77 liver transplants were recruited to the study. Multivariate analysis was utilized to identify significant risk factors for EAD. A nomogram was constructed according to the contributions of the risk factors. The predictive values were determined by discrimination and calibration methods. A cohort of 30 patients was recruited to validate this predictive model. Four independent risk factors, including donor age, intraoperative blood loss, preoperative alanine aminotransferase (ALT), and reperfusion total bilirubin, were identified and used to build the nomogram. The c-statistics of the primary cohort and the validation group were 0.846 and 0.767, respectively. The calibration curves for the probability of EAD presented an acceptable agreement between the prediction by the nomogram and the actual incidence. In conclusion, the study developed a new nomogram for predicting the risk of EAD following living donor liver transplantation. This model may help clinicians to determine individual risk of EAD following living donor liver transplantation.

A simple scoring model for predicting early graft failure and postoperative mortality after liver transplantation

INTRODUCTION AND OBJECTIVES

Graft failure and postoperative mortality are the most serious complications after liver transplantation. The aim of this study is to establish a prognostic scoring system to predict graft and patient survival based on serum transaminases levels that are routinely used during the postoperative period in human cadaveric liver transplants.

PATIENTS AND METHODS

Postoperative graft failure and patient mortality after liver transplant were analyzed from a consecutive series of 1299 patients undergoing cadaveric liver transplantation. This was correlated with serum liver function tests and the rate of reduction in transaminase levels over the first postoperative week. A cut-off transaminase level correlating with graft and patient survival was calculated and incorporated into a scoring system.

RESULTS

Aspartate-aminotransferase (AST) on postoperative day one showed significant correlation with early graft failure for levels above 723U/dl and early postoperative mortality for levels above 750U/dl. AST reduction rate (day 1 to 3) greater than 1.8 correlated with reduced graft failure and greater than 2 with mortality. Alanine-aminotransferase (ALT) reduction in the first 48h post transplantation also correlated with outcomes.

CONCLUSION

A scoring system with these three variables allowed us to classify our patients into three groups of risk for early graft failure and mortality.

Effect of Remote Ischemic Preconditioning Conducted in Living Liver Donors on Postoperative Liver Function in Donors and Recipients Following Liver Transplantation: A Randomized Clinical Trial

OBJECTIVE

This study aimed to assess the effects of remote ischemic preconditioning (RIPC) on liver function in donors and recipients after living donor liver transplantation (LDLT).

BACKGROUND

Ischemia reperfusion injury (IRI) is known to be associated with graft dysfunction after liver transplantation. RIPC is used to lessen the harmful effects of IRI.

METHODS

A total of 148 donors were randomly assigned to RIPC (n = 75) and control (n = 73) groups. RIPC involves 3 cycles of 5-minute inflation of a blood pressure cuff to 200 mm Hg to the upper arm, followed by 5-minute reperfusion with cuff deflation. The primary aim was to assess postoperative liver function in donors and recipients and the incidence of early allograft dysfunction and graft failure in recipients.

RESULTS

RIPC was not associated with any differences in postoperative aspartate aminotransferase (AST) and alanine aminotransferase levels after living donor hepatectomy, and it did not decrease the incidence of delayed graft hepatic function (6.7% vs 0.0%, P = 0.074) in donors. AST level on postoperative day 1 [217.0 (158.0, 288.0) vs 259.5 (182.0, 340.0), P = 0.033] and maximal AST level within 7 postoperative days [244.0 (167.0, 334.0) vs 296.0 (206.0, 395.5), P = 0.029) were significantly lower in recipients who received a preconditioned graft. No differences were found in the incidence of early allograft dysfunction (4.1% vs 5.6%, P = 0.955) or graft failure (1.4% vs 5.6%, P = 0.346) among recipients.

CONCLUSIONS

RIPC did not improve liver function in living donor hepatectomy. However, RIPC performed in liver donors may be beneficial for postoperative liver function in recipients after living donor liver transplantation.

The Influence of Dietary Chicken Egg Lysozyme on the Growth Performance, Blood Health, and Resistance Against Escherichia coli in the Growing Rabbits' Cecum

The dietary chicken egg lysozyme (LZM) at different concentrations was tested on the growth performance, blood health, and resistance against Escherichia coli of growing rabbits. A total number of 48 rabbits averaged 611.25 g (5 weeks of age) of APRI line-rabbits (Egyptian developed line) were allocated into four treatments (three replicates and each contained four rabbits) of 5-week weaning APRI rabbits. The first group was fed a basal diet without LZM supplementation and served as a control group, whereas the remaining groups of rabbits were fed a basal diet supplemented with LZM at 50, 100, and 200 mg/kg diet, respectively, for 8 weeks. The obtained results revealed that rabbits fed the basal diet supplemented with different concentrations of LZM linearly (P < 0.05) displayed improved growth performance and reduced feed intake and FCR. The best result was for rabbits fed a 200 mg per kg diet supplemented with LZM, followed by a 100 mg per kg diet. The total count of Escherichia coli and Clostridium count was linearly (P < 0.05) decreased by adding LZM at 100 and 200 mg/kg in the diets compared to the control groups. In contrast, total bacterial count and the total count of Lactobacilli had increased considerably by increasing LZM at different levels relative to the control groups. The LZM supplementation linearly (P < 0.05) increased hematological parameters (RBCs, PCV, Hb, and WBCs) together with an increase in lymphocyte count compared to the control group. The total protein and globulin concentrations were significantly (P < 0.05) increased by feeding with LZM. On the other hand, ALT, AST, urea, and creatinine were significantly (P < 0.05) decreased by increasing LZM supplementation. It could be concluded that supplementation of the rabbit's diet with chicken egg LZM was able to improve the growth performance and hematological and serum biochemical parameters compared with the control group. Therefore, LZM is required at the rate of the hobx100-200 mg/kg diet as a potential feed additive and a friendly alternative for antibiotics in rabbit feed.

Impact of Rifaximin Therapy on Ischemia/Reperfusion Injury in Liver Transplantation: A Propensity Score-Matched Analysis

Intestinal microbiota is thought to play an important role in hepatic ischemia/reperfusion injury (IRI) after liver transplantation (LT). Rifaximin, a nonabsorbable antibiotic used to treat encephalopathy, exhibits antibacterial activity within the gut. We report the first study examining the impact of pre-LT rifaximin use on reducing hepatic IRI and inflammatory cell infiltration after LT. This retrospective single-center study included adult LT recipients from January 2013 through June 2016. Patients were divided into 2 groups based on duration of rifaximin use before LT: rifaximin group (≥28 days) and control group (none or <28 days). Patients receiving other antibiotics within 28 days of LT and re-LTs were excluded. Outcomes and messenger RNA (mRNA) expression in the graft were compared by 1:1 propensity score-matching and multivariate analyses. On 1:1 matching (n = 39/group), rifaximin patients had lower postoperative serum transaminase levels and lower early allograft dysfunction (EAD; 10.3% versus 33.3%; P = 0.014). Of the matched patients, 8 patients (n = 4/group) had postreperfusion liver biopsies (approximately 2 hours after reperfusion) available for mRNA analysis. Hepatic expression of CD86 (macrophage marker) and cathepsin G (neutrophil marker) was significantly lower in rifaximin patients than controls (P < 0.05). The multivariate analysis included 458 patients. Rifaximin treatment <28 days was identified as an independent risk factor EAD in all patients and those with high Model for End-Stage Liver Disease (MELD) score (MELD ≥35; n = 230). In conclusion, the propensity score-matched and multivariate analyses suggest a therapeutic role of rifaximin in reducing EAD. Pre-LT rifaximin administration exerted a protective function against early liver injury, potentially by suppressing inflammatory cell activation in the graft.

Effect of Fermented Corn-Soybean Meal on Serum Immunity, the Expression of Genes Related to Gut Immunity, Gut Microbiota, and Bacterial Metabolites in Grower-Finisher Pigs

Fermented corn-soybean meal (fermented feed, FF) is commonly used in swine production, but the effects of FF on gut health remain unclear. In this study, serum immunity, mRNA abundances of antimicrobial peptides (AMPs) and Toll-like receptors (TLR1-9), bacterial abundance in the duodenum and colon, and colonic metabolic phenotypes were determined in crossbred barrows (Duroc × Landrace × Large White) fed FF or normal feed (unfermented feed, UF) (n = 6). When compared to the UF group, the results showed that serum levels of IgG and IgM were significantly increased in FF group pigs (P < 0.05). FF significantly decreased the abundances of Bacteroides and Verrucomicrobia in the duodenum and decreased the abundances of Bacteroides, Proteobacteria, and Verrucomicrobia in the colon while it significantly increased the abundances of Firmicutes and Actinobacteria (P < 0.05). Furthermore, a Spearman's correlation analysis showed that serum immunity and the expression of genes related to gut immunity were associated with bacterial strains at the family level. Moreover, differentially abundant colonic microbiota were associated with colonic metabolites. LC-MS data analyses identified a total of 1,351 metabolites that markedly differed between the UF and FF groups. C5-Branched dibasic acid metabolism was significantly upregulated whereas the purine metabolism was significantly downregulated (P < 0.05) in the colonic digesta of pigs in the FF meal group compared to the UF meal group. Collectively, these results indicated that FF meal could influence serum immunity and the expression of genes related to gut immunity, correlating with the gut microbiota and bacterial metabolites in grower-finisher pigs. This study may provide an alternative strategy for improving the intestinal health of grower-finisher pigs.

Urinary Neutrophil Gelatinase Associated Lipocalins (NGALs) predict acute kidney injury post liver transplant

BACKGROUND

Acute Kidney Injury, a common complication of liver transplant, is associated with a significant increase in the risk of morbidity, mortality and graft loss. Current diagnostic criteria leaves a delay in diagnosis allowing further potential irreversible damage. Early biomarkers of renal injury are of clinical importance and Neutrophil Gelatinase Associated Lipocalins (NGALs) and Syndecan-1 were investigated.

METHODS

AKI was defined according to the Acute Kidney Injury Network criteria. Urine and blood samples were collected pre-operatively, immediately post-op and 24 h post reperfusion to allow measurement of NGAL and Syndecan-1 levels.

RESULTS

13 of 27 patients developed an AKI. Patients who developed AKI had significantly higher peak transaminases. Urinary NGAL, plasma NGAL and Syndecan-1 levels were significantly elevated in all patients post reperfusion. Urinary NGAL levels immediately post-op were significantly higher in patients who developed an AKI than those that didn't [1319 ng/ml vs 46.56 ng/ml, p ≤ 0.001]. ROC curves were performed and urinary NGAL levels immediately post-op were an excellent biomarker for AKI with an area under the curve of 0.948 (0.847-1.00).

CONCLUSIONS

Urinary NGAL levels measured immediately post-op accurately predict the development of AKI and their incorporation into clinical practise could allow early protocols to be developed to treat post transplant AKI.

Dietary Lysozyme Alters Sow's Gut Microbiota, Serum Immunity and Milk Metabolite Profile

The aim of current study was to determine variations in sow's gut microbiota, serum immunity, and milk metabolite profile mediated by lysozyme supplementation. Twenty-four pregnant sows were assigned to a control group without supplementation and two treatments with 0.5 kg/t and 1.0 kg/t lysozyme provided in formula feed for 21 days (n = 8 per treatment). Microbiota analysis and metagenomic predictions were based on 16s RNA high-throughput sequencing. Milk metabolome was assessed by untargeted liquid chromatography tandem mass spectrometry. Serum biochemical indicators and immunoglobulins were also determined. Gut microbial diversity of sows receiving 1.0 kg/t lysozyme treatment was significantly reduced after the trial. Spirochaetes, Euryarchaeota, and Actinobacteria significantly increased while Firmicutes showed a remarkable reduction in 1.0 kg/t group compared with control. Lysozyme addition rebuilt sow's gut microbiota to beneficial composition identified by reduced richness of Escherichia coli and increased abundance of Lactobacillus amylovorus. Accordingly, microbial metabolic functions including pyrimidine metabolism, purine metabolism, and amino acid related enzymes were significantly up-regulated in 1.0 kg/t group. Microbial metabolic phenotypes like the richness of Gram-positive bacteria and oxidative stress tolerance were also significantly reduced by lysozyme treatment. Serum alanine transaminase (ALT) activity and IgA levels were significantly down-regulated in the 1.0 kg/t group compared with control, but IgM levels showed a significantly increase in 1.0 kg/t group. Milk metabolites such as L-glutamine, creatine, and L-arginine showed significantly dose-dependent changes after treatment. Overall, lysozyme supplementation could effectively improve the composition, metabolic functions, and phenotypes of sow's gut microbiota and it also benefit sows with better serum immunity and milk composition. This research could provide theoretical support for further application of lysozyme in promoting animal gut health and prevent pathogenic infections in livestock production.

Impact of Donor Pre-Procurement Cardiac Arrest (PPCA) on Clinical Outcomes in Liver Transplantation

Background

Transplantation of liver grafts from deceased donors who experienced cardiac arrest prior to liver procurement is now common. This single-center study analyzed the impact of pre-donation arrest time on clinical outcomes in liver transplantation.

Material/Methods

Records of all orthotopic liver transplants performed at a single center over a 15-year period were reviewed. Donor records were reviewed and total arrest time was calculated as cumulative minutes. Post-transplant liver graft function was assessed using laboratory values. Graft survival was assessed with Cox regression analysis.

Results

Records for 1830 deceased donor transplants were reviewed, and 521 donors experienced pre-procurement cardiac arrest (28%). Median arrest time was 21 min (mean 25 min, range 1–120 min). After transplant, the peak alanine aminotransferase and bilirubin levels for liver grafts from donors with arrest were lower compared to those for donors without arrest (p<0.001). Early allograft dysfunction occurred in 25% (arrest) and 28% (no arrest) of patients (p=0.22). There were no differences in risk of early graft loss (3% vs. 3%, p=0.84), length of hospital stay (10 vs. 10 days, p=0.76), and 1-year graft survival (89% vs. 89%, p=0.94). Cox regression analysis comparing 4 groups (no arrest, <20 min, 20–40 min, and >40 min arrest) demonstrated no statistically significant difference in survival at 10 years. Subgroup analysis of 93 donation after cardiac death grafts showed no significant difference for these same outcomes.

Conclusions

These results support the use of select deceased liver donors who experience pre-donation cardiac arrest. Pre-donation arrest may be associated with less early allograft dysfunction, but had no impact on long-term clinical outcomes. The results for donation after cardiac death donors were similar.

Systematic review on the treatment of deceased organ donors

BACKGROUND

Currently, there is no consensus on which treatments should be a part of standard deceased-donor management to improve graft quality and transplantation outcomes. The objective of this systematic review was to evaluate the effects of treatments of the deceased, solid-organ donor on graft function and survival after transplantation.

METHODS

Pubmed, Embase, Cochrane, and Clinicaltrials.gov were systematically searched for randomized controlled trials that compared deceased-donor treatment versus placebo or no treatment.

RESULTS

A total of 33 studies were selected for this systematic review. Eleven studies were included for meta-analyses on three different treatment strategies. The meta-analysis on methylprednisolone treatment in liver donors (two studies, 183 participants) showed no effect of the treatment on rates of acute rejection. The meta-analysis on antidiuretic hormone treatment in kidney donors (two studies, 222 participants) indicates no benefit in the prevention of delayed graft function. The remaining meta-analyses (seven studies, 334 participants) compared the effects of 10 min of ischaemic preconditioning on outcomes after liver transplantation and showed that ischaemic preconditioning improved short-term liver function, but not long-term transplant outcomes.

CONCLUSIONS

There is currently insufficient evidence to conclude that any particular drug treatment or any intervention in the deceased donor improves long-term graft or patient survival after transplantation.

Expanding the donor pool: Donation after circulatory death and living liver donation do not compromise the results of liver transplantation

Because of the shortfall between the number of patients listed for liver transplantation (LT) and the available grafts, strategies to expand the donor pool have been developed. Donation after circulatory death (DCD) and living donor (LD) grafts are not universally used because of the concerns of graft failure, biliary complications, and donor risks. In order to overcome the barriers for the implementation of using all 3 types of grafts, we compared outcomes after LT of DCD, LD, and donation after brain death (DBD) grafts. Patients who received a LD, DCD, or DBD liver graft at the University of Toronto were included. Between January 2009 through April 2017, 1054 patients received a LT at our center. Of these, 77 patients received a DCD graft (DCD group); 271 received a LD graft (LD group); and 706 received a DBD graft (DBD group). Overall biliary complications were higher in the LD group (11.8%) compared with the DCD group (5.2%) and the DBD group (4.8%; P < 0.001). The 1-, 3-, and 5-year graft survival rates were similar between the groups with 88.3%, 83.2%, and 69.2% in the DCD group versus 92.6%, 85.4%, and 84.7% in the LD group versus 90.2%, 84.2%, and 79.9% in the DBD group (P = 0.24). Furthermore, the 1-, 3-, and 5-year patient survival was comparable, with 92.2%, 85.4%, and 71.6% in the DCD group versus 95.2%, 88.8%, and 88.8% in the LD group versus 93.1%, 87.5%, and 83% in the DBD group (P = 0.14). Multivariate Cox regression analysis revealed that the type of graft did not impact graft survival. In conclusion, DCD, LD, and DBD grafts have similar longterm graft survival rates. Increasing the use of LD and DCD grafts may improve access to LT without affecting graft survival rates. Liver Transplantation 24 779-789 2018 AASLD.

Ex situ liver perfusion: Organ preservation into the future

In recent years, remarkable progress has occurred in the development of technologies to support ex situ liver perfusion. Building upon extensive preclinical studies in large animal models, pilot and randomized clinical trials have been initiated, and preliminary outcomes suggest more optimal protection of both standard and extended criteria liver grafts. There currently exists an incredible opportunity and need to further refine this technology, determine appropriate viability measures to predict usable liver grafts, and to explore potent protective additive strategies to further optimize the quality of extended criteria organs. These findings will have major bearing in expanding the limited liver donor pool, and may save lives where up to a quarter of listed patients die on wait-lists. Herein we offer a brief overview of the history and current status of ex situ liver perfusion, and discuss future directions that will likely have major impact on the practice of clinical liver transplantation.

The case for normothermic machine perfusion in liver transplantation

In recent years, there has been growing interest in normothermic machine perfusion (NMP) as a preservation method in liver transplantation. In most countries, because of a donor organ shortage, an unacceptable number of patients die while awaiting transplantation. In an attempt to increase the number of donor organs available, transplant teams are implanting a greater number of high-risk livers, including those from donation after circulatory death, older donors, and donors with steatosis. NMP maintains the liver ex vivo on a circuit by providing oxygen and nutrition at 37°C. This permits extended preservation times, the ability to perform liver viability assessment, and the potential for liver-directed therapeutic interventions during preservation. It is hoped that this technology may facilitate the enhanced preservation of marginal livers with improved posttransplant outcomes by reducing ischemia/reperfusion injury. Clinical trials have demonstrated its short-term superiority over cold storage in terms of early biochemical liver function, and it is anticipated that it may result in increased organ utilization, helping to reduce the number of wait-list deaths. However, further studies are required to demonstrate longer-term efficacy and the impact on biliary complications as well as further knowledge to exploit and maximize the potential of this exciting new technology. Liver Transplantation 24 269-275 2018 AASLD.

Cold storage or normothermic perfusion for liver transplantation: probable application and indications

PURPOSE OF REVIEW

Preservation of the liver via normothermic machine perfusion (NMP) is rapidly becoming an area of great academic and clinical interest. This review focuses on the benefits and limitations of NMP and where the role for static cold storage may lie.

RECENT FINDINGS

Clinical studies have recently been published reporting the use of NMP in liver preservation for transplantation. They have described the technology to be well tolerated and feasible with potentially improved posttransplant outcomes. NMP facilitates extended preservation times as well as the potential to increase organ utilization through viability assessment and regeneration. However, this technology is considerably more costly than cold storage and carries significant logistical challenges. Cold storage remains the gold standard preservation for standard criteria livers with good long-term patient and graft survival.

SUMMARY

NMP is an exciting new technological advancement in liver preservation, which is likely to have a positive impact in liver transplantation. However, randomized controlled trials are required to justify its inclusion into standard practice and provide evidence to support its efficacy.

Remote ischaemic preconditioning in orthotopic liver transplantation (RIPCOLT trial): a pilot randomized controlled feasibility study

BACKGROUND

Ischaemia Reperfusion (IR) injury is a major cause of morbidity, mortality and graft loss following Orthotopic Liver Transplantation (OLT). Utilising marginal grafts, which are more susceptible to IR injury, makes this a key research goal. Remote Ischaemic Preconditioning (RIPC) has been shown to ameliorate hepatic IR injury in experimental models. Whether RIPC can reduce IR injury in human liver transplant recipients is unknown.

METHODS

Forty patients undergoing liver transplantation were randomized to RIPC or a sham. RIPC was induced through three 5 min cycles of alternate ischaemia and reperfusion of the left leg prior to surgery. Data on clinical outcomes was collected prospectively. Per-operative cytokine levels were measured.

RESULTS

Fourty five of 51 patients approached (88%) were willing to enroll in the study. Five patients were excluded and 40 randomized, of which 20 underwent RIPC which was successfully completed in all patients. There were no complications following RIPC. Median day 3 AST levels were slightly higher in the RIPC group (221 IU vs 149 IU, p = 1.00).

CONCLUSIONS

RIPC is acceptable and safe in liver transplant recipients. This study has not demonstrated evidence of a reduction in short-term measures of IR injury. Longer follow up will be required and consideration of an altered protocol.

Early acute kidney injury after liver transplantation: Predisposing factors and clinical implications

AIM

To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation.

METHODS

This was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 × baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor (< 1000 IU/L), moderate (1000-5000 IU/L) or severe (> 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome.

RESULTS

Out of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P < 0.001) and intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049).

CONCLUSION

HIRI has an important role in the development of AKI post-OLT and has a negative impact on patient outcomes, especially when occurring alongside AKI.

A systematic review and meta-analysis of donor ischaemic preconditioning in liver transplantation

Ischaemic preconditioning (IPC) is a strategy to reduce ischaemia-reperfusion (IR) injury. Its benefit in human liver transplantation is unclear. The aim of this study was to analyse the current evidence for donor IPC in liver transplantation. Systematic review and meta-analysis of studies involving IPC of liver transplant donors. Ovid Medline, Embase and Cochrane CENTRAL were searched up until January 2015. Data retrieved included the primary outcomes of 1-year mortality, incidence of primary graft non-function (PGNF) and retransplantation. Secondary outcomes included aspartate aminotransferase (AST) levels on day 3 post-op. Pooled odds ratios (ORs) were calculated for dichotomous data and mean weighted ratios for continuous data. Ten studies included 593 patients (286 IPC; 307 control). IPC was associated with a reduction in mortality at 1 year (6% vs. 11%) although this was not statistically significant (OR 0.54, 95% C.I. 0.28-1.04, P = 0.06). The IPC group had a significantly lower day 3 AST level (WMD -66.41iU, P = 0.04). This meta-analysis demonstrates that IPC reduces liver injury following transplantation and produces a large reduction in 1-year mortality which was not statistically significant. Confirmation of clinical benefit from IPC requires an adequately powered prospective RCT.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1^th and the 5^th day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Protocol for a prospective randomized controlled trial of recipient remote ischaemic preconditioning in orthotopic liver transplantation (RIPCOLT trial)

Abstract

Ischaemic reperfusion (IR) injury is a major cause of graft loss, morbidity and mortality following orthotopic liver transplantation (OLT). Demand for liver transplantation has resulted in increasing use of marginal grafts that are more prone to IR injury. Remote ischaemic preconditioning (RIPC) reduces IR injury in experimental models, but recipient RIPC has not been evaluated clinically.

Methods

A single-centre double-blind randomized controlled trial (RCT) is planned to test the hypothesis that recipient RIPC will reduce IR injury. RIPC will be performed following recipient anaesthetic induction but prior to skin incision. The protocol involves 3 cycles of 5 min of lower limb occlusion with a pneumatic tourniquet inflated to 200 mmHg alternating with 5 min of reperfusion. In the control group, the sham will involve the cuff being placed on the thigh but without being inflated.

The primary endpoint is ability to recruit patients to the trial and safety of RIPC. The key secondary endpoint is a reduction in serum aspartate transferase levels on the third post-operative day.

Discussion

RIPC is a promising strategy to reduce IR injury in liver transplant recipients as there is a clear experimental basis, and the intervention is both inexpensive and easy to perform. This is the first trial to investigate RIPC in liver transplant recipients.

Trial registration

Clinicaltrials.gov NCT00796588

Electronic supplementary material

The online version of this article (doi:10.1186/s13737-016-0033-4) contains supplementary material, which is available to authorized users.