The demand for liver transplantation is rising, as is the prevalence of steatotic liver disease. Steatotic grafts have inferior outcomes post-transplantation, due to increased sensitivity to ischaemia-reperfusion injury. We aimed to formally evaluate the impact of visually assessed liver steatosis in grafts donated following brainstem (DBD) versus circulatory death (DCD).

NHS registry on adult liver transplantation was reviewed retrospectively (2006-2019). We used multiple-imputation for missing data and adjusted regression models with interaction terms to compare the impact of visually assessed donor graft steatosis on transplant outcome.

9217 recipients of deceased donor grafts were included (DBD = 7349; DCD = 1868). Multivariable cox regression revealed that the negative impact on graft survival was significantly different in DCD and DBD livers (interaction P = 0.011 and P = 0.043). The largest impact was in DCD livers (moderate steatosis: aHR = 1.851, 1.296-2.645, P = 0.001 and aHR = 5.426; severe steatosis: 1.723-17.090, P = 0.004). Visually assessed steatosis did not predict longer-term graft survival in the DBD cohort.

The impact of visually assessed steatosis on post-transplant outcome is far greater in DCD grafts, despite an identical method of steatosis assessment. This highlights novel therapeutics should be considered for steatotic DCD grafts to allow this growing sector of the donor pool to be safely utilised.

Fibrinogen, a pivotal plasma glycoprotein, plays an essential role in hemostasis by serving as the precursor to fibrin, which forms the structural framework of blood clots. Beyond coagulation, fibrinogen influences immune responses, inflammation, and tissue repair. Oxidative stress, characterized by an imbalance between reactive oxygen species (ROS) and antioxidants, induces fibrinogen oxidation, significantly altering its structure and function. This narrative review synthesizes findings from in vitro, ex vivo, and clinical studies, emphasizing the impact of fibrinogen oxidation on clot formation, architecture, and degradation. Oxidative modifications result in denser fibrin clots with thinner fibers, reduced permeability, and heightened resistance to fibrinolysis. These structural changes exacerbate prothrombotic conditions in cardiovascular diseases, diabetes, chronic inflammatory disorders and cancer. In contrast, "low-dose" oxidative stress may elicit protective adaptations in fibrinogen, preserving its function. The review also highlights discrepancies in experimental findings due to variability in oxidation protocols and patient conditions. Understanding the interplay between oxidation and fibrinogen function could unveil therapeutic strategies targeting oxidative stress. Antioxidant therapies or selective inhibitors of detrimental oxidation hold potential for mitigating thrombotic risks. However, further research is essential to pinpoint specific fibrinogen oxidation sites, clarify their roles in clot dynamics, and bridge the gap between basic research and clinical practice.

The quantity of regions of interest (ROIs) constitutes the primary determinant of the time investment in image analysis. In the context of proton density fat-fraction (PDFF) magnetic resonance imaging (MRI) conducted on liver grafts in ex vivo conditions, this research systematically examines various ROI sampling strategies. The findings of this study furnish essential insights, offering a foundation for optimizing time efficiency while ensuring precise assessment of hepatic steatosis before the crucial process of liver transplantation.

This was a retrospective analysis of a prospective study and included 35 liver grafts with histopathological steatosis that underwent 3T PDFF MRI in ex vivo. One ROI of 1 cm2 was selected for each hepatic segment, and any combination of ROIs in 1-8 liver segments was used, resulting in 511 combinations. Using intraclass correlation coefficients (ICCs) and Bland-Altman analyses, the PDFFs of all these combinations were compared with the 9-ROI average PDFF. There was a moderate correlation between the average PDFF and the histological findings (R = 0.47, P＜0.01).

The average 9-ROI PDFF of all liver grafts was 4.07 ± 4.35 % (0.870-20.904). All strategies with ≥5 ROIs had intraclass correlation coefficient (ICC) ≥ 0.995 and absolute limits of agreement (|LOA|)≤ 1.5 %. Overall, 54 of 84 (67.5 %) 3-ROI sampling strategy had ICC ≥0.995, and 70 of 84 (70 %) had |LOA|≤ 1.5 %. A total of 111 of 126 (88.1 %) 4-ROI sampling strategy had ICC ≥0.995, and 125 of 126 (99.2 %) had |LOA| ≤ 1.5 %.

The employment of the 5-ROI sampling strategy proves instrumental in both time conservation and precise assessment of hepatic steatosis within liver grafts during the ex vivo phase preceding liver transplantation.

The rising prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) has led to an increased occurrence of steatotic liver grafts (SLG) in liver transplantation (LT). However, the implications of SLG on post-transplant de novo hepatic steatosis (PTHS) and advanced fibrosis (≥F3) remain uncertain. This study aimed to characterize PTHS and ≥ F3 using magnetic resonance imaging (MRI) in patients who underwent LT for non-MASLD indications and to examine their relationship with SLG.

Post-LT patients with implant biopsy fat content data were recruited for MRI assessments. MRI-proton density fat fraction (MRI-PDFF) and MR elastography (MRE) were performed using a 1.5 Tesla Optima 450 W MR scanner with a 3D volumetric sequence. PTHS and ≥ F3 were defined as MRI-PDFF ≥5% and MRE ≥3.64 kPa, respectively. SLG was defined as implant biopsy fat content ≥5%.

A total of 292 patients (70.5% men, median age at LT: 51.9 years, 22.6% with SLG) were recruited. The majority (73.6%) were transplanted for hepatitis B virus (HBV)-related complications. MRI performed at a median of 12.2 years post-LT identified PTHS in 27.4 and 10.6% of patients. PTHS was independently associated with SLG (OR 2.067, 95% CI 1.082-3.951), central obesity (OR 3.952, 95% CI 1.768-8.832), and hypertension (OR 2.510, 95% CI 1.268-4.966). In contrast, ≥F3 was associated with sex, change in BMI, and abnormal liver biochemistry but not with PTHS or SLG.

MRI identified a high prevalence of PTHS, which was associated with SLG and metabolic risk factors among Chinese patients transplanted for non-MASLD indications. Advanced graft fibrosis was not associated with PTHS or SLG.

Several donor-specific factors influence the functional recovery and long-term outcomes of liver grafts. This study investigated the association between donor fasting glucose (DFG) and recipient outcomes after living donor liver transplantation (LDLT) in 950 cases at a single center. Patients were divided into two groups: low-DFG (< 85 mg/dL, n = 120) and control (≥ 85 mg/dL, n = 830). The five-year graft survival rate was significantly lower in the low-DFG group (71.5%) compared to the control group (80.0%) (P = 0.02). Multivariable Cox regression analysis showed that low DFG was independently associated with graft loss (hazard ratio 1.72, 95% CI 1.15-2.56, P = 0.008). In propensity score-matched groups, the low-DFG group also had lower survival rates (71% vs. 83.1%, P = 0.004). The presence of additional risk factors, such as low graft-to-recipient weight ratio, older donor age, and longer cold ischemic time, further reduced graft survival in the low-DFG group. A DFG level < 85 mg/dL is associated with higher risk of graft failure after LDLT, especially when combined with other risk factors. Low DFG should be considered a prognostic marker in LDLT planning, with potential to improve patient outcomes as further research clarifies the underlying pathophysiological mechanisms.

The viability of the liver pre-transplant depends on the type of donor, age, medical history, circumstances of death, result of analytics, and complementary exploration of the abdominal cavity. Abdominal ultrasound is the initial option for the assessment of previously unknown liver disease, such as the qualitative determination of hepatic steatosis. The presence of hepatic steatosis is considered a risk factor for graft failure after liver transplantation, therefore, at the time of clinical assessment of the donor or its presence in the macroscopic assessment in the operating room can be cause for rejection of the organ by the transplant teams. The objective is the usefulness of ultrasound for the diagnosis of hepatic steatosis and degree of agreement with macroscopic and microscopic findings of the hepatic graft accepted for transplantation.

We analyzed the results of ultrasound in the population of donors accepted for assessment of the hepatic graft for transplantation and the correlation with the macroscopic finding determined by surgery in the operating room and with the microscopic finding determined by histology in the transplanted grafts. The determinations made describe the demographic variables of the different types of donors, probability of presenting hepatic steatosis, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of the use of ultrasound and degree of agreement with macroscopic and microscopic findings.

Of the grafts evaluated, hepatic steatosis was described by ultrasound in 48 of 299 cases (16.05%) and by macroscopic aspect in 79 of 299 cases (26.4%). Coinciding in 29 of 79 (36.70%) of the cases (kappa = 0.328, P = .000). The 63.21% (189/299) of the livers evaluated were valid for transplantation. Of the valid grafts, 9.6% presented steatosis by ultrasound, 8.4% by macroscopy, and 21.4% by histology. An ultrasound that reports hepatic steatosis implies an increase of 1.87 of log-odds that the donor presents macroscopic steatosis (95% confidence interval [CI] = 3.34-12.65, P = .000) according to the binary logistic regression model. The sensitivity of ultrasound for hepatic steatosis based on microscopy was 29%, specificity 91%, PPV 66%, and NPV 68%.

Given the moderate or low agreement among ultrasound, macroscopy, and histology, the bedside portable ultrasound for the diagnosis of hepatic steatosis seems to be a method that undervalues the presence of hepatic steatosis in potential donors accepted for liver transplantation.

This study explores a combined strategy of Raman and reflectance spectroscopy for quantifying liver fat content and fat droplet size, crucial in assessing donor livers. By using Monte Carlo simulations and experimental setups with oil-in-water phantoms, our findings indicate that Raman scattering can solely differentiate between varying fat contents. At the same time, reflectance intensity is influenced by both fat content and oil droplet size, with a more pronounced sensitivity to fat droplet size. This study demonstrates the efficacy of combined Raman and reflectance spectroscopy in assessing liver steatosis and fat droplet size, potentially aiding in assessing donor livers for transplantation.

Living donor liver transplantation using hepatic steatosis-improved grafts mitigates donor shortage. Herein, we aimed to evaluate the safety and feasibility of right-lobe adult-to-adult living donor liver transplantation using grafts improved through donor weight loss.

In this retrospective study conducted in a single institution in the Republic of Korea, we reviewed the medical records of living liver donors who lost ≥ 10% of their body weight to improve steatosis before right lobe donation between January 2015 and December 2020. Overall, 1040 right-lobe donors were included, with 150 and 890 donors in the weight loss and control (non-steatosis) groups, respectively.

We performed 1:1 individual matching using the greedy matching method, by which 124 patients were included in each group. The median period from the date of the first visit to donation was 113 (interquartile range: 78-184) days in the weight loss group. As body weight changed from 82.8 ± 13.7 kg to 70.8 ± 11.8 kg (p < 0.0001), body mass index also improved from 27.8 ± 3.9 kg/m2 to 23.8 ± 3.1 kg/m2 (p < 0.0001). No significant between-group differences existed in the postoperative laboratory data for living donors and recipients. The incidence of postoperative complications in donors was comparable between the groups (control group, 9.7%; weight loss group, 13.7%; p = 0.3185). The graft and recipient survival rates were comparable between the groups (p = 1.000).

Weight loss through diet and exercise significantly could improve hepatic steatosis in living donor candidates for liver transplantation, with the surgical outcomes in recipients and donors being equivalent to those in recipients and non-steatotic donors.

Liver transplantation (LT) is a major treatment for patients with end-stage liver diseases. Steatosis is a significant risk factor for primary graft nonfunction and associated with poor long-term graft outcomes. Traditionally, the evaluation of steatosis is based on frozen section examination to estimate the percentage of hepatocytes containing lipid vesicles. However, this visual evaluation correlates poorly with the true lipid content. This study aimed to address the potential of infrared (IR) microspectroscopy for rapidly estimating lipid content in the context of LT and assessing its impact on survival. Clinical data were collected for >20 months from 58 patients who underwent transplantation. For each liver graft, macrovacuolar steatosis and microvesicular steatosis were evaluated through histologic examination of frozen tissue section. Triglycerides (TG) were further quantified using gas phase chromatography coupled with a flame ionization detector (GC-FID) and estimated by IR microspectroscopy. A linear relationship and significant correlation were observed between the TG measured by GC-FID and those estimated using IR microspectroscopy (R2 = 0.86). In some cases, microvesicular steatosis was related to high lipid content despite low levels of macrovacuolar steatosis. Seven patients experienced posttransplantation liver failure, including 5 deceased patients. All patients underwent transplantation with grafts containing significantly high TG levels. A concentration of 250 nmol/mg was identified as the threshold above which the risk of failure after LT significantly increased, affecting 35% of patients. Our study established a strong correlation between LT outcomes and lipid content. IR microspectroscopy proved to be a rapid and reliable approach for assessing the lipid content in clinical settings.

Cardiovascular events represent a major cause of non-graft-related death after liver transplant. Evidence suggest that chronic inflammation associated with a remarkable oxidative stress in the presence of endothelial dysfunction and procoagulant environment plays a major role in the promotion of thrombosis. However, the underlying molecular mechanisms are not completely understood.

In order to elucidate the mechanisms of posttransplant thrombosis, the aim of the present study was to investigate the role of oxidation-induced structural and functional fibrinogen modifications in liver transplant recipients.

A case-control study was conducted on 40 clinically stable liver transplant recipients and 40 age-matched, sex-matched, and risk factor-matched controls. Leukocyte reactive oxygen species (ROS) production, lipid peroxidation, glutathione content, plasma antioxidant capacity, fibrinogen oxidation, and fibrinogen structural and functional features were compared between patients and controls.

Patients displayed enhanced leukocyte ROS production and an increased plasma lipid peroxidation with a reduced total antioxidant capacity compared with controls. This systemic oxidative stress was associated with fibrinogen oxidation with fibrinogen structural alterations. Thrombin-catalyzed fibrin polymerization and fibrin resistance to plasmin-induced lysis were significantly altered in patients compared with controls. Moreover, steatotic graft and smoking habit were associated with high fibrin degradation rate.

ROS-induced fibrinogen structural changes might increase the risk of thrombosis in liver transplant recipients.

Graft survival is a critical end point in adult-to-adult living donor liver transplantation (ALDLT), where graft procurement endangers the lives of healthy individuals. Therefore, ALDLT must be responsibly performed in the perspective of a positive harm-to-benefit ratio. This study aimed to develop a risk prediction model for early (3 months) graft failure (EGF) following ALDLT. Donor and recipient factors associated with EGF in ALDLT were studied using data from the European Liver Transplant Registry. An artificial neural network classification algorithm was trained on a set of 2073 ALDLTs, validated using cross-validation, tested on an independent random-split sample (n=518), and externally validated on United Network for Organ Sharing Standard Transplant Analysis and Research data. Model performance was assessed using the AUC, calibration plots, and decision curve analysis. Graft type, graft weight, level of hospitalization, and the severity of liver disease were associated with EGF. The model ( http://ldlt.shinyapps.io/eltr_app ) presented AUC values at cross-validation, in the independent test set, and at external validation of 0.69, 0.70, and 0.68, respectively. Model calibration was fair. The decision curve analysis indicated a positive net benefit of the model, with an estimated net reduction of 5-15 EGF per 100 ALDLTs. Estimated risks>40% and<5% had a specificity of 0.96 and sensitivity of 0.99 in predicting and excluding EGF, respectively. The model also stratified long-term graft survival ( p <0.001), which ranged from 87% in the low-risk group to 60% in the high-risk group. In conclusion, based on a panel of donor and recipient variables, an artificial neural network can contribute to decision-making in ALDLT by predicting EGF risk.

Although the incidence of recipients and donors with overweight and obesity is increasing worldwide, few reports have focused on outcomes of preoperative weight reduction (WR) in living-donor liver transplantation (LDLT). Therefore, we examined the outcomes and the impact of WR on the postoperative course.

We analyzed 217 consecutive LDLT procedures performed from 2017 to 2022. We divided the recipients and donors into a WR group and non-WR group.

Twenty-two recipients (10.1%) achieved WR (preoperative recipient WR [RWR] group), reducing their weight by 6.8% ± 6.0% within 2.2 ± 1.4 months with a significant decrease in body mass index (BMI) (P < .0001). The RWR group showed no significant differences in short-term postoperative outcomes (operative factors, postoperative liver function tests, amount of ascites, and morbidity) or in the graft survival rate as a long-term outcome (P = .24) compared with the non-RWR group. Forty-one donors (18.9%) achieved WR (preoperative donor WR [DWR] group), reducing their weight by 9.7% ± 6.3% within 3.2 ± 5.8 months with a significant decrease in BMI (P < .0001). Compared with the non-DWR group, the DWR group showed no significant differences in short-term postoperative outcomes between themselves and recipients or in the graft survival rate (P = .49). Furthermore, WR resulted in an increase to 32 donor-eligible and 6 recipient-eligible patients.

WR in LDLT recipients and donors had no harmful effect on postoperative outcomes and should lead to increase recipients' chance of undergoing LDLT and to expand the donor pool.

Liver disease is the third leading cause of premature death in the UK. Transplantation is the only successful treatment for end-stage liver disease but is limited by a shortage of suitable donor organs. As a result, up to 20% of patients on liver transplant waiting lists die before receiving a transplant. A third of donated livers are not suitable for transplant, often due to steatosis. Hepatic steatosis, which affects 33% of the UK population, is strongly associated with obesity, an increasing problem in the potential donor pool. We have recently tested defatting interventions during normothermic machine perfusion (NMP) in discarded steatotic human livers that were not transplanted. A combination of therapies including forskolin (NKH477) and L-carnitine to defat liver cells and lipoprotein apheresis filtration were investigated. These interventions resulted in functional improvement during perfusion and reduced the intrahepatocellular triglyceride (IHTG) content. We hypothesise that defatting during NMP will allow more steatotic livers to be transplanted with improved outcomes.

In the proposed multi-centre clinical trial, we will randomly assign 60 livers from donors with a high-risk of hepatic steatosis to either NMP alone or NMP with defatting interventions. We aim to test the safety and feasibility of the defatting intervention and will explore efficacy by comparing ex-situ and post-reperfusion liver function between the groups. The primary endpoint will be the proportion of livers that achieve predefined functional criteria during perfusion which indicate potential suitability for transplantation. These criteria reflect hepatic metabolism and injury and include lactate clearance, perfusate pH, glucose metabolism, bile composition, vascular flows and transaminase levels. Clinical secondary endpoints will include proportion of livers transplanted in the two arms, graft function; cell-free DNA (cfDNA) at follow-up visits; patient and graft survival; hospital and ITU stay; evidence of ischemia-reperfusion injury (IRI); non-anastomotic biliary strictures and recurrence of steatosis (determined on MRI at 6 months).

This study explores ex-situ pharmacological optimisation of steatotic donor livers during NMP. If the intervention proves effective, it will allow the safe transplantation of livers that are currently very likely to be discarded, thereby reducing waiting list deaths.

ISRCTN ISRCTN14957538. Registered in October 2022.

Liver transplantation (LT) is the only definitive treatment for end-stage liver disease, yet the UK has seen a 400% increase in liver disease-related deaths since 1970, constrained further by a critical shortage of donor organs. This shortfall has necessitated the use of extended criteria donor organs, including those with evidence of steatosis. The impact of hepatic steatosis (HS) on graft viability remains a concern, particularly for donor livers with moderate to severe steatosis which are highly sensitive to the process of ischaemia-reperfusion injury (IRI) and static cold storage (SCS) leading to poor post-transplantation outcomes. This review explores the pathophysiological predisposition of steatotic livers to IRI, the limitations of SCS, and alternative preservation strategies, including novel organ preservation solutions (OPS) and normothermic machine perfusion (NMP), to mitigate IRI and improve outcomes for steatotic donor livers. By addressing these challenges, the liver transplant community can enhance the utilisation of steatotic donor livers which is crucial in the context of the global obesity crisis and the growing need to expand the donor pool.

In the realm of liver transplantation, accurately determining hepatic steatosis levels is crucial. Recognizing the essential need for improved diagnostic precision, particularly for optimizing diagnosis time by swiftly handling easy-to-solve cases and allowing the expert time to focus on more complex cases, this study aims to develop cutting-edge algorithms that enhance the classification of liver biopsy images. Additionally, the challenge of maintaining data privacy arises when creating automated algorithmic solutions, as sharing patient data between hospitals is restricted, further complicating the development and validation process. This research tackles diagnostic accuracy by leveraging novel techniques from the rapidly evolving field of quantum machine learning, known for their superior generalization abilities. Concurrently, it addresses privacy concerns through the implementation of privacy-conscious collaborative machine learning with federated learning. We introduce a hybrid quantum neural network model that leverages real-world clinical data to assess non-alcoholic liver steatosis accurately. This model achieves an image classification accuracy of 97%, surpassing traditional methods by 1.8%. Moreover, by employing a federated learning approach that allows data from different clients to be shared while ensuring privacy, we maintain an accuracy rate exceeding 90%. This initiative marks a significant step towards a scalable, collaborative, efficient, and dependable computational framework that aids clinical pathologists in their daily diagnostic tasks.

The growing disparity between the rising demand for liver transplantation (LT) and the limited availability of donor organs has prompted a greater reliance on older liver grafts. Traditionally, utilizing livers from elderly donors has been associated with outcomes inferior to those achieved with grafts from younger donors. By accounting for additional risk factors, we hypothesize that the utilization of older liver grafts has a relatively minor impact on both patient survival and graft viability.

To evaluate the impact of donor age on LT outcomes using multivariate analysis and comparing young and elderly donor groups.

In the period from April 2013 to December 2018, 656 adult liver transplants were performed at the University Hospital Merkur. Several multivariate Cox proportional hazards models were developed to independently assess the significance of donor age. Donor age was treated as a continuous variable. The approach involved univariate and multivariate analysis, including variable selection and assessment of interactions and transformations. Additionally, to exemplify the similarity of using young and old donor liver grafts, the group of 87 recipients of elderly donor liver grafts (≥ 75 years) was compared to a group of 124 recipients of young liver grafts (≤ 45 years) from the dataset. Survival rates of the two groups were estimated using the Kaplan-Meier method and the log-rank test was used to test the differences between groups.

Using multivariate Cox analysis, we found no statistical significance in the role of donor age within the constructed models. Even when retained during the entire model development, the donor age's impact on survival remained insignificant and transformations and interactions yielded no substantial effects on survival. Consistent insignificance and low coefficient values suggest that donor age does not impact patient survival in our dataset. Notably, there was no statistical evidence that the five developed models did not adhere to the proportional hazards assumption. When comparing donor age groups, transplantation using elderly grafts showed similar early graft function, similar graft (P = 0.92), and patient survival rates (P = 0.86), and no significant difference in the incidence of postoperative complications.

Our center's experience indicates that donor age does not play a significant role in patient survival, with elderly livers performing comparably to younger grafts when accounting for other risk factors.

Orthotopic liver transplantation (OLT) is a lifesaving procedure. However, grafts may fail due to primary nonfunction (PNF). In the past, we demonstrated PNFs to be mainly associated with fatty allografts, and given its unpredictable nature, the development of a disease model is urgently needed. In an effort to investigate mechanism of fatty allograft-associated PNFs, we induced fatty liver disease in donor animals by feeding rats a diet deficient in methionine and choline (MCD). We performed OLT with allografts of different grades of hepatic steatosis and compared the results to healthy ones. We assessed liver function by considering serum biochemistries, and investigated genome wide responses following OLT of healthy and fatty allograft-associated PNFs. Furthermore, we performed immunohistochemistry to evaluate markers of oxidative stress and reperfusion injury, inflammation, glycolysis and gluconeogenesis, lactate transport, and its utilization as part of the Cori cycle. Strikingly, PNFs are strictly lipid content dependent. Nonetheless, a fat content of ≤17% and an increase in the size of hepatocytes of ≤11% (ballooning) greatly improved outcome of OLTs and the hepatic microcirculation. Mechanistically, PNFs arise from a dysfunctional Cori cycle with complete ablation of the lactate transporter SLC16A1. Thus, lipid-laden hepatocytes fail to perform gluconeogenesis via lactate reutilization, and the resultant hyperlactatemia and lactic acidosis causes cardiac arrhythmogenicity and death. Furthermore, the genomic and immunohistochemistry investigations underscore a dysfunctional Krebs cycle with impaired energy metabolism in lipid-burdened mitochondria. Together, we show fatty allografts to be highly vulnerable towards ischemia/reperfusion-injury, and stabilizing the Cori cycle is of critical importance to avert PNFs.

Liver transplantation (LT) offers patients with decompensated cirrhosis the best chance at long-term survival. With the rising prevalence of diabetes, further clarity is needed on the impact of receiving a liver allograft from a donor with diabetes on post-LT outcomes. This study aims to evaluate the impact of donor diabetes on clinical outcomes after LT.

This is a retrospective analysis of the United Network for Organ Sharing registry data of LT recipients from January 1, 2000, to December 31, 2021. Outcomes analysis was performed using Cox proportional model for all-cause mortality and graft failure. Confounding was reduced by coarsened exact matching causal inference analysis.

Of 66 960 donors identified, 7178 (10.7%) had diabetes. Trend analysis revealed a longitudinal increase in the prevalence of donor diabetes ( P  < 0.001). Importantly, donor diabetes was associated with increased all-cause mortality (hazard ratio [HR]: 1.13; 95% confidence interval [CI], 1.07-1.19; P  < 0.001) and graft failure (HR: 1.16; 95% CI, 1.11-1.22; P  < 0.001). Receiving donor organ with diabetes reduced graft survival in patients who received LT for nonalcoholic steatohepatitis cirrhosis (HR: 1.26; 95% CI, 1.13-1.41; P  < 0.001) but not other etiologies of cirrhosis.

Donor diabetes was associated with worse outcomes post-LT, particularly in patients receiving LT for nonalcoholic steatohepatitis cirrhosis. Future studies are needed to better understand the mechanism underlying this association to develop better risk stratification and clinical practice to improve the outcomes of the transplanted patients.

Donors with fatty livers are considered to address the shortage of livers for transplantation, but those livers are particularly sensitive to ischemia-reperfusion injury (IRI), and an increased incidence of graft failure is observed. Kupffer cells account for 20-35% of liver nonparenchymal cells, and have been shown to participate in the process of IRI and inflammatory reactions of hepatic steatosis. NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) is an intracellular sensor activated by Kupffer cells to promote generation and participates in IRI. Dynamics-associated protein 1 (Drp1) is one of the main proteins regulating mitochondrial division and exacerbates IRI by affecting mitochondrial dynamics. The mechanism of interaction of Kupffer cells with Drp1 and NLRP3 to aggravate IRI has not been clarified.

A mouse model of hepatic steatosis was established by feeding the mice with a high-fat diet. In vitro experiments were performed using AML12 normal mouse liver cells and RAW264.7 mononuclear macrophage cells cultured in medium with palmitate and oleic acid. Western blotting and immunohistochemical (IHC) staining were used to detect the expression of NLRPP3 and Drp1 in IRI in the control and high-fat diet groups. The expression of F4/80+ cells during IRI in hepatic steatosis was verified by IHC staining, and the role of NLRPP3 and Drp1 in Kupffer-cell mediated IRI was investigated by targeting Drp-1 inhibition.

Drp1 and NLRP3 expression was increased during IRI in hepatic steatosis, and the expression of Drp1 and NLRP3 were decreased after the elimination of Kupffer cells. That indicated Kupffer cells were involved in the process of IRI in hepatic steatosis through the action of Drp1 and NLRP3. After Drp1 inhibition, liver function was restored and NLRP3 expression level was reduced.

Kupffer cells aggravated IRI in hepatic steatosis via NLRP3 and Drp1. Drp1 inhibitors might be useful as specific therapeutics to alleviate IRI in hepatic steatosis and may have promise in case of liver donor shortage.

Liver regeneration (LR) is a complex process involving intricate networks of cellular connections, cytokines, and growth factors. During the early stages of LR, hepatocytes accumulate lipids, primarily triacylglycerol, and cholesterol esters, in the lipid droplets. Although it is widely accepted that this phenomenon contributes to LR, the impact of lipid droplet deposition on LR remains a matter of debate. Some studies have suggested that lipid droplet deposition has no effect or may even be detrimental to LR. This review article focuses on transient regeneration-associated steatosis and its relationship with the liver regenerative response.

Transplant pathology plays a critical role in ensuring that transplanted organs function properly and the immune systems of the recipients do not reject them. To improve outcomes for transplant recipients, accurate diagnosis and timely treatment are essential. Recent advances in artificial intelligence (AI)-empowered digital pathology could help monitor allograft rejection and weaning of immunosuppressive drugs. To explore the role of AI in transplant pathology, we conducted a systematic search of electronic databases from January 2010 to April 2023. The PRISMA checklist was used as a guide for screening article titles, abstracts, and full texts, and we selected articles that met our inclusion criteria. Through this search, we identified 68 articles from multiple databases. After careful screening, only 14 articles were included based on title and abstract. Our review focuses on the AI approaches applied to four transplant organs: heart, lungs, liver, and kidneys. Specifically, we found that several deep learning-based AI models have been developed to analyze digital pathology slides of biopsy specimens from transplant organs. The use of AI models could improve clinicians' decision-making capabilities and reduce diagnostic variability. In conclusion, our review highlights the advancements and limitations of AI in transplant pathology. We believe that these AI technologies have the potential to significantly improve transplant outcomes and pave the way for future advancements in this field.

An accurate estimation of liver fat content is necessary to predict how a donated liver will function after transplantation. Currently, a pathologist needs to be available at all hours of the day, even at remote hospitals, when an organ donor is procured. Even among expert pathologists, the estimation of liver fat content is operator-dependent. Here we describe the development of a low-cost, end-to-end artificial intelligence platform to evaluate liver fat content on a donor liver biopsy slide in real-time. The hardware includes a high-resolution camera, display, and GPU to acquire and process donor liver biopsy slides. A deep learning model was trained to label and quantify fat globules in liver tissue. The algorithm was deployed on the device to enable real-time quantification and characterization of fat content for transplant decision-making. This information is displayed on the device and can also be sent to a cloud platform for further analysis.

Liver allograft steatosis is a significant risk factor for postoperative graft dysfunction and has been associated with inferior patient and graft survival, particularly in the case of moderate or severe macrovesicular steatosis. In recent years, the increasing incidence of obesity and fatty liver disease in the population has led to a higher proportion of steatotic liver grafts being used for transplantation, making the optimization of their preservation an urgent necessity. This review discusses the mechanisms behind the increased susceptibility of fatty livers to ischemia-reperfusion injury and provides an overview of the available strategies to improve their utilization for transplantation, with a focus on preclinical and clinical evidence supporting donor interventions, novel preservation solutions, and machine perfusion techniques.

Dimethyl fumarate (DMF), a therapeutic agent for relapsing-remitting multiple sclerosis, has cytoprotective and antioxidant effects. Ferroptosis, a pathological cell death process, is recently shown to play a vital part in ischemia-reperfusion injury (IRI). This study aimed to unveil the suppressive role of DMF on ferroptosis in liver IRI. The anti-ferroptosis effect of DMF on hepatic IRI was investigated using a liver IRI mouse model and a hypoxia-reoxygenation injury (HRI) model in alpha mouse liver (AML12) cells. Serum transaminase concentrations reflected liver function. Hematoxylin and eosin staining was used to assess liver damage. Cell viability was evaluated utilizing the CCK-8 assay. Malondialdehyde (MDA), the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, and BODIPY 581/591C11 were measured to estimate the injury caused by lipid peroxidation. Western blotting and real-time polymerase chain reaction (RT-PCR) were performed to explore the underlying molecular mechanisms. We demonstrated the anti-ferroptosis effects of DMF both in vivo and in vitro. DMF treatment ameliorated hepatic IRI. KEGG enrichment analysis and transmission electron microscopy revealed a close relationship between ferroptosis and liver IRI. Furthermore, DMF protected against HRI by inhibiting ferroptosis via activating the nuclear factor E2-related factor 2 (NRF2) pathway. Interestingly, NRF2 knockdown notably decreased the expression of SLC7A11 and HO-1 and blocked the anti-ferroptosis effects of DMF. DMF inhibits ferroptosis by activating the NRF2/SLC7A11/HO-1 axis and exerts a protective effect against hepatic IRI.

Liver-transplantation activity is limited by the shortage of grafts. Donor-liver macrovesicular steatosis predisposes to ischemia-reperfusion injury and is associated with reduced graft survival. The increasing prevalence of fatty-liver disease underlines the importance of identifying macrovesicular steatosis in potential donor livers. We analyzed liver grafts discarded for transplantation, and particularly the role of gamma-glutamyltransferase (GGT) in predicting graft steatosis.

One-hundred sixty rejected cadaveric-donor liver grafts were studied. Donor selection was based on clinical data, and macroscopic graft inspection. Discarded grafts were biopsied at procurement of non-liver organs.

The most common reasons for discarding the graft were abnormal liver tests, ultrasound-verified steatosis and history of harmful alcohol use. GGT correlated moderately with macrovesicular steatosis (r = 0.52, p < 0.001), but poorly with microvesicular steatosis (r = 0.36, p < 0.001). Increased correlation between GGT and macrovesicular steatosis was observed among alcohol abusers (r = 0.67, p < 0.001). Area under the curve (AUC) of GGT for predicting >30% macrovesicular steatosis was 0.79 (95% CI 0.71-0.88), and for >60% steatosis, 0.79 (95% CI 0.68-0.90). The optimal GGT-cut off for detecting >30% and >60% macrovesicular steatosis were, respectively, 66 U/L (sensitivity 76% and specificity 68%) and 142 U/L (sensitivity 66% and specificity 83%). Among alcohol users, a GGT value >90 U/L showed 100% sensitivity for >60% macrovesicular steatosis. AUC for GGT in predicting fibrosis Stages 2-4 was 0.82 (95% CI 0.71-0.92, p < 0.001, optimal cut off 68, sensitivity 92%, specificity 61%).

Abnormal liver values, steatosis and harmful alcohol use were the main reasons for discarding liver-graft offers in Finland. GGT proved useful in predicting moderate and severe liver graft macrovesicular steatosis.

Steatotic livers represent a potentially underutilized resource to increase the donor graft pool; however, 1 barrier to the increased utilization of such grafts is the heterogeneity in the definition and the measurement of macrovesicular steatosis (MaS). Digital imaging software (DIS) may better standardize definitions to study posttransplant outcomes. Using HALO, a DIS, we analyzed 63 liver biopsies, from 3 transplant centers, transplanted between 2016 and 2018, and compared macrovesicular steatosis percentage (%MaS) as estimated by transplant center, donor hospital, and DIS. We also quantified the relationship between DIS characteristics and posttransplant outcomes using log-linear regression for peak aspartate aminotransferase, peak alanine aminotransferase, and total bilirubin on postoperative day 7, as well as logistic regression for early allograft dysfunction. Transplant centers and donor hospitals overestimated %MaS compared with DIS, with better agreement at lower %MaS and less agreement for higher %MaS. No DIS analyzed liver biopsies were calculated to be >20% %MaS; however, 40% of liver biopsies read by transplant center pathologists were read to be >30%. Percent MaS read by HALO was positively associated with peak aspartate aminotransferase (regression coefficient= 1.04 1.08 1.12 , p <0.001), peak alanine aminotransferase (regression coefficient = 1.04 1.08 1.12 , p <0.001), and early allograft dysfunction (OR= 1.10 1.40 1.78 , p =0.006). There was no association between HALO %MaS and total bilirubin on postoperative day 7 (regression coefficient = 0.99 1.01 1.04 , p =0.3). DIS provides reproducible quantification of steatosis that could standardize MaS definitions and identify phenotypes associated with good clinical outcomes to increase the utilization of steatite livers.

Transplant pathology of donors is a highly specialized field comprising both the evaluation of organ donor biopsy for the oncological risk transmission and to guide the organ allocation. Timing is critical in transplant procurement since organs must be recovered as soon as possible to ensure the best possible outcome for the recipient. To all this is added the fact that the evaluation of a donor causes difficulties in many cases and the impact of these assessments is paramount, considering the possible recovery of organs that would have been erroneously discarded or, conversely, the possibly correct discarding of donors with unacceptable risk profiles. In transplant pathology histology is still the gold standard for diagnosis dictating the subsequent decisions and course of clinical care. Digital pathology has played an important role in accelerating healthcare progression and nowadays artificial intelligence powered computational pathology can effectively improve diagnostic needs, supporting the quality and safety of the process. Mapping the shape of the journey would suggest a progressive approach from supervised to semi/unsupervised models, which would involve training these models directly for clinical endpoints. In machine learning, this generally delivers better performance, compensating for a potential lack in interpretability. With planning and enough confidence in the performance of learning-based methods from digital pathology and artificial intelligence, there is great potential to augment the diagnostic quality and correlation with clinical endpoints. This may improve the donor pool and vastly reduce diagnostic and prognostic errors that are known but currently are unavoidable in transplant donor pathology.

The recipient muscle status is closely associated with postoperative poor survival in recipients of living donor liver transplantation (LDLT). However, it is uncertain whether LDLT donor muscle quality and quantity affect graft quality. Hence, we analyzed the correlation between donor muscle status and graft function. We measured the skeletal muscle mass index (SMI) and intramuscular adipose tissue content (IMAC) of 380 LDLT donors. We examined the correlation between donor SMI or IMAC and graft mortality, the occurrence rates of small-for-size graft (SFSG) syndrome, and 6-month graft survival rates. The donor SMI had no effect on the occurrence of SFSG syndrome and graft survival, while a high IMAC in both male and female donors was significantly correlated with the rate of SFSG syndrome [high vs low: (male donors) 15.8% vs. 2.5%, p = 0.0003; (female donors) 12.8% vs. 3.1%, p = 0.0234] and 6-month graft survival rates [(male donors) 87.7% vs 95.9%, p = 0.02; (female donors) 83.0% vs. 99.0%, p < 0.0001]. Multivariate analysis revealed that a high donor IMAC (HR; 5.42, CI; 2.13-13.8, p = 0.0004) was an independent risk factor for 6-month graft survival, and the donor IMAC is useful for donor selection for high-risk recipients.

The rising global prevalence of metabolic diseases has increased the prevalence of non-alcoholic fatty liver disease (NAFLD), leading to an increase in cases of NAFLD-related hepatocellular carcinoma (HCC). To provide an updated literature review detailing epidemiology, risk factors, pathogenic pathways, and treatment strategies linked to NAFLD-related HCC, we conducted a literature search on PubMed from its inception to December 31, 2021. About 25% of the global population suffers from NAFLD. The annual incidence of HCC among NAFLD patients is approximately 1.8 per 1,000 person-years. Older age, male sex, metabolic comorbidities, unhealthy lifestyle habits (such as smoking and alcohol consumption), physical inactivity, genetic susceptibility, liver fibrosis, and degree of cirrhosis in NAFLD patients are important risk factors for NAFLD-related HCC. Therefore, low-calorie diet, moderate-intensity exercise, treatment of metabolic comorbidities, and cessation of smoking and alcohol are the main measures to prevent NAFLD-related HCC. In addition, all patients with advanced NAFLD-related fibrosis or cirrhosis should be screened for HCC. Immune suppression disorders and changes in the liver microenvironment may be the main pathogenesis of NAFLD-related HCC. Hepatic resection, liver transplantation, ablation, transarterial chemoembolization, radiotherapy, targeted drugs, and immune checkpoint inhibitors are used to treat NAFLD-related HCC. Lenvatinib treatment may lead to better overall survival, while immune checkpoint inhibitors may lead to worse overall survival. Given the specific risk factors for NAFLD-related HCC, primary prevention is key. Moreover, the same treatment may differ substantially in efficacy against NAFLD-related HCC than against HCC of other etiologies.

Acute kidney injury (AKI) is frequent after liver transplantation (LT) and correlates with later development of chronic kidney disease. Its etiology is multifactorial and combines pre-, intra-, and postoperative factors. Additionally, the liver graft itself seems an important element in the development of AKI, yet the detailed mechanisms remain unclear. We hypothesized that grafts of LT recipients developing significant early AKI may show distinct proteomic alterations, and we set out to identify proteome differences between LT recipients developing moderate or severe AKI (n = 7) and LT recipients without early renal injury (n = 7). Liver biopsies obtained one hour after reperfusion were assessed histologically and using quantitative proteomics. Several cytokines and serum amyloid A2 (SAA2) were analyzed in serum samples obtained preoperatively, 2−4 h, and 20−24 h after graft reperfusion, respectively. LT induced mild histological alterations without significant differences between groups but uniformly altered liver function tests peaking on postoperative day 1, with a trend towards more severe alterations in patients developing AKI. Global quantitative proteomic analysis revealed 136 proteins differing significantly in their expression levels (p < 0.05, FC 20%): 80 proteins had higher and 56 had lower levels in the AKI group. Most of these proteins were related to immune and inflammatory responses, host defense, and neutrophil degranulation. No differences between the studied pro- and anti-inflammatory cytokines or SAA2 between groups were found at any moment. Our results suggest that grafts of LT patients who develop early AKI reveal a distinct proteome dominated by an early yet prominent activation of the innate immunity. These findings support the hypothesis that AKI after LT may be favored by certain graft characteristics.

The quality and size of liver grafts are critical factors that influence living-donor liver transplantation (LDLT) function and safety. However, the biomarkers used for predicting graft quality are lacking. In this study, we sought to identify unique graft quality markers, aside from donor age, by using the livers of non-human primates. Hepatic gene microarray expression data from young and elderly cynomolgus macaques revealed a total of 271 genes with significantly increased expression in the elderly. These candidate genes were then narrowed down to six through bioinformatics analyses. The expression patterns of these candidate genes in human donor liver tissues were subsequently examined. Importantly, we found that grafts exhibiting up-regulated expression of these six candidate genes were associated with an increased incidence of liver graft failure. Multivariable analysis further revealed that up-regulated expression of LRRN2 (encoding leucine-rich repeat protein, neuronal 2) in donor liver tissue served as an independent risk factor for graft failure (odds ratio 4.50, confidence interval 2.08-9.72). Stratification based on graft expression of LRRN2 and donor age was also significantly associated with 6-month graft survival rates. Conclusion: Up-regulated LRRN2 expression of liver graft is significantly correlated with graft failure in LDLT. In addition, combination of graft LRRN2 expression and donor age may represent a promising marker for predicting LDLT graft quality.

During liver procurement, surgeons mostly rely on their subjective visual inspection of the liver to assess the degree of fatty infiltration, for which misclassification is common. We developed a Raman system, which consists of a 1064 nm laser, a handheld probe, optical filters, photodiodes, and a lock-in amplifier for real-time assessment of liver fat contents. The system performs consistently in normal and strong ambient light, and the excitation incident light penetrates at least 1 mm into duck fat phantoms and duck liver samples. The signal intensity is linearly correlated with MRI-calibrated fat contents of the phantoms and the liver samples.

Machine perfusion (MP) has been shown worldwide to offer many advantages in liver transplantation, but it still has some gray areas. The purpose of the study is to evaluate the donor risk factors of grafts, perfused with any MP, that might predict an ineffective MP setting and those would trigger post-transplant early allograft dysfunction (EAD). Data from donors of all MP-perfused grafts at six liver transplant centers have been analyzed, whether implanted or discarded after perfusion. The first endpoint was the negative events after perfusion (NegE), which is the number of grafts discarded plus those that were implanted but lost after the transplant. A risk factor analysis for NegE was performed and marginal grafts for MP were identified. Finally, the risk of EAD was analyzed, considering only implanted grafts. From 2015 to September 2019, 158 grafts were perfused with MP: 151 grafts were implanted and 7 were discarded after the MP phase because they did not reach viability criteria. Of 151, 15 grafts were lost after transplant, so the NegE group consisted of 22 donors. In univariate analysis, the donor risk index >1.7, the presence of hypertension in the medical history, static cold ischemia time, and the moderate or severe macrovesicular steatosis were the significant factors for NegE. Multivariate analysis confirmed that macrosteatosis >30% was an independent risk factor for NegE (odd ratio 5.643, p = 0.023, 95% confidence interval, 1.27-24.98). Of 151 transplanted patients, 34% experienced EAD and had worse 1- and 3-year-survival, compared with those who did not face EAD (NoEAD), 96% and 96% for EAD vs. 89% and 71% for NoEAD, respectively (p = 0.03). None of the donor/graft characteristics was associated with EAD even if the graft was moderately steatotic or fibrotic or from an aged donor. For the first time, this study shows that macrovesicular steatosis >30% might be a warning factor involved in the risk of graft loss or a cause of graft discard after the MP treatment. On the other hand, the MP seems to be useful in reducing the donor and graft weight in the development of EAD.

Graft macrosteatosis can predispose to a higher risk of graft loss so we sought to redefine acceptable cutoffs for graft steatosis.

Data of 26,103 donors who underwent liver transplantation (LT) between January 2004 and December 2018 from the UNOS-STAR database were utilized. A high-risk steatotic (HRS) graft and a low-risk steatotic (LRS) graft were defined as ≥20% and <20% macrosteatosis, respectively. High-risk steatotic grafts were further classified as grafts with 20-29% (G1S grafts), 30-39% (G2S grafts), and ≥40% steatosis (G3S grafts). Outcomes between groups were compared.

LRS grafts had excellent graft (93.3 and 87.7%) and overall survival (95.4 and 90.5%) at 90 days and 1 year. Compared to LRS grafts, G1S, G2S, and G3S grafts had worse graft and overall survival at 90 days and 1-year (p <0.001). There was no difference in graft or overall survival of G1S or G3S grafts compared to G2S grafts until after adjustment in which G3S grafts were found to be associated with an increased risk of graft loss-aHR 1.27 (1.03-1.57), p = 0.02.

Liver grafts can be categorized into three categories: (1) <20% or "very low risk", (2) 20-39% or "low-to-moderate risk", and usually acceptable, and (3) ≥40% steatosis or "moderate-to-high risk".

Da BL, Satiya J, Heda RP, et al. Outcomes after Liver Transplantation with Steatotic Grafts: Redefining Acceptable Cutoffs for Steatotic Grafts. Euroasian J Hepato-Gastroenterol 2022;12(Suppl 1):S5-S14.