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Liver endothelial cell (LEC) damage is essential in the pathogenesis of ischemia-reperfusion injury (IRI) in transplant recipients. We analyzed the mechanism of LEC resistance against IRI by using a novel recombinant soluble form of P selectin glycoprotein ligand 1, tandem P selectin glycoprotein ligand immunoglobulin (TSGL-Ig), in a mouse model of hepatic cold preservation (4°C in University of Wisconsin solution for 20 h) and syngeneic orthotopic liver transplantation (OLT). Unlike controls, TSGL-Ig protected orthotopic liver transplants against ischemia-reperfusion (IR) stress, shown by depressed serum alanine aminotransferase levels, well-preserved hepatic architecture, and improved survival (42% vs. 92%). TSGL-Ig suppressed neutrophil/macrophage sequestration and proinflammatory cytokine/chemokine programs in OLT. Treatment with TSGL-Ig mitigated LEC activation (P and E selectin, VCAM-1 and intercellular adhesion molecule 1 expression). In parallel in vitro studies, TSGL-Ig diminished cellular damage in H2 O2 -stressed LEC cultures (lactic acid dehydrogenase and alanine aminotransferase levels). Increased thioredoxin, glutamate-cysteine ligase, NAD(P)H quinone dehydrogenase 1, and hypoxia-inducible factor 1α expression, along with transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), implied that TSGL-Ig exerts antioxidant functions in IR-stressed OLT and H2 O2 -stressed LECs. Indeed, Nrf2-deficient livers suffered fulminant IRI compared with WT despite concomitant TSGL-Ig therapy. Thus, TSGL-Ig is not only acting as a competitive antagonist blocking leukocyte migration into IR-stressed liver, but it may also act directly as an agonist stimulating Nrf2-mediated cytoprotection in LECs. This study supports the role of P selectin signaling in hepatic homeostasis in OLT, with broad implications for tissue damage conditions.

Although pretransplant diabetes is a risk factor for mortality post-liver transplant, the underlying mechanism has not been fully defined. In a murine liver partial warm ischemia model, we addressed the question of how diabetes/hyperglycemia impacted tissue inflammatory injuries against ischemia reperfusion (IR), focusing on the advanced glycation endproduct (AGE) and its receptor (RAGE) pathway. Our results showed that hepatocellular injury was exacerbated in streptozotocin-induced diabetic mice against IR, in association with hyper-inflammatory immune activation in livers. Serum levels of AGEs, but not HMGB1, were increased in diabetic mice in response to liver IR. Both RAGE antagonist peptides and small interfering RNA alleviated liver injuries and inhibited inflammatory immune activation against IR in diabetic, but not normal, mice. Kupffer cells (KCs)/macrophages, but not hepatocytes, from diabetic mice expressed significantly higher levels of RAGE, leading to their hyper-inflammatory responsiveness to both TLR ligands and AGEs. In vitro, hyperglycemia increased macrophage RAGE expression and enhanced their TLR responses. Our results demonstrated that activation of the AGE-RAGE signaling pathway in KCs was responsible for hyper-inflammatory immune responses and exacerbated hepatocellular injuries in diabetic/hyperglycemic hosts against liver IR.

Background Clinical and laboratory criteria are not reliable predictors of deceased donor liver graft quality. Intraoperative assessment of experienced surgeons is the gold standard. Standardizing and quantifying this assessment is especially needed now that regional sharing is the rule. We prospectively evaluated a novel, simple, rapid, noninvasive, quantitative measure of liver function performed before graft procurement. Materials and methods Using a portable, finger-probe-based device, indocyanine green plasma disappearance rates (ICG-PDR) were measured in adult brain-dead donors in the local donor service area before organ procurement. Results were compared with graft function and outcomes. Both donor and recipient teams were blinded to ICG-PDR measurements. Results Measurements were performed on 53 consecutive donors. Eleven liver grafts were declined by all centers because of quality; the other 42 grafts were transplanted. Logistic regression analysis showed ICG-PDR to be the only donor variable to be significantly associated with 7-d graft survival. Donor risk index, donor age, and transaminase levels at peak or procurement were not significantly associated with 7-d graft survival. Conclusions We report the successful use of a portable quantitative means of measuring liver function and its association with graft survival. These data warrant further exploration in a variety of settings to evaluate acceptable values for donated liver grafts.

The Model for End-Stage Liver Disease (MELD) system has dramatically increased the number of recipients requiring pretransplant renal replacement therapy (RRT) prior to liver transplantation (LT). Factors affecting post-LT outcomes and the need for intraoperative RRT (IORRT) were analyzed in 500 consecutive recipients receiving pretransplant RRT, including comparisons among recipients not receiving IORRT (No-IORRT, n = 401), receiving planned IORRT (Pl-IORRT, n = 70), and receiving emergent, unplanned RRT after LT initiation (Em-IORRT, n = 29). Despite a median MELD of 39, overall 30-day, 1-, 3- and 5-year survivals were 93%, 75%, 68% and 65%, respectively. Em-IORRT recipients had significantly more intraoperative complications (arrhythmias, postreperfusion syndrome, coagulopathy) compared with both No-IORRT and Pl-IORRT and greater 30-day graft loss (28% vs. 10%, p = 0.004) and need for retransplantation (24% vs. 10%, p = 0.099) compared with No-IORRT. A risk score based on multivariate predictors of IORRT accurately identified recipients with chronic (sensitivity 84%, specificity 72%, concordance-statistic [c-statistic] 0.829) and acute (sensitivity 93%, specificity 61%, c-statistic 0.776) liver failure requiring IORRT. In this largest experience of LT in recipients receiving RRT, we report excellent survival and propose a practical model that accurately identifies recipients who may benefit from IORRT. For this select group, timely initiation of IORRT reduces intraoperative complications and improves posttransplant outcomes.

Although the roles of the metabolic stress in organ ischemia-reperfusion injury (IRI) have been well recognized, the question of whether and how these stress responses regulate innate immune activation against IR remains unclear. In a murine liver partial warm ischemia mode, we showed that prolonged ischemia triggered endoplasmic reticulum (ER) stress response, particularly, the activating transcription factor 6 (ATF6) branch, in liver Kupffer cells (KCs) and altered their responsiveness against Toll-like receptor (TLR) stimulation. Ischemia-primed cells increased pro-, but decreased anti-, inflammatory cytokine productions. Alleviation of ER stress in vivo by small chemical chaperon 4-phenylbutyrate or ATF6 small interfering RNA (siRNA) diminished the pro-inflammatory priming effect of ischemia in KCs, leading to the inhibition of liver immune response against IR and protection of livers from IRI. In vitro, ATF6 siRNA abrogated the ER stress-mediated pro-inflammatory enhancement of macrophage TLR4 response, by restricting NF-κB and restoring Akt activations. Thus, ischemia primes liver innate immune cells by ATF6-mediated ER stress response. The IR-induced metabolic stress and TLR activation function in synergy to activate tissue inflammatory immune response.

BACKGROUND: The optimal endoscopic protocol for treating postorthotopic liver transplantation (OLT) anastomotic biliary strictures (ABSs) has not been established. OBJECTIVE: To review the technique and outcomes of endoscopic retrograde cholangiopancreatography (ERCP) with maximal stenting for post-OLT ABSs at our institution. DESIGN: Retrospective study. SETTING: Tertiary-care center. PATIENTS: Eighty-three patients with a diagnosis of ABS. INTERVENTIONS: ERCP with balloon dilation and maximal stenting. MAIN OUTCOME MEASUREMENTS: Stricture resolution, stricture recurrence, and complication rates. RESULTS: Of 83 patients, 69 completed treatment, of whom 65 (94%) achieved resolution and 4 (6%) required hepaticojejunostomy (HJ). The remaining 14 patients who did not achieve a study endpoint were excluded (9 deaths or redo OLT unrelated to biliary disease, and 5 without follow-up). Comparing the resolution group and the HJ group, there were, respectively, 8.0 and 3.5 total stents (P = .021), 2.5 and 1.3 stents per ERCP (P = .018) (maximum = 9), 4.2 and 2.8 ERCPs (P = .15), and 20 and 22 months from OLT to ABS diagnosis (P = .19). There were 2 cases of ERCP pancreatitis (0.7%) and 2 cases of periprocedural bacteremia of 286 total ERCPs and no episodes of cholangitis caused by stent occlusion. In a median follow-up of 11 months (range 0-39), 2 (3%) patients had ABS recurrence that was successfully re-treated with ERCP. A multivariate Cox model demonstrated that treatment success was directly related to the number of stents used in total and per ERCP. LIMITATIONS: Retrospective study, single endoscopist. CONCLUSIONS: Our maximal stenting protocol for ABSs is effective, safe, rarely associated with ABS recurrence, and conducive to less frequent stent exchange and therefore fewer ERCPs compared with conventional treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Over the past decade, ERCP has become the preferred method of treatment for biliary strictures in patients after orthotopic liver transplantation (OLT). Although data strongly support ERCP for treating anastomotic strictures, the little information available for the role of ERCP in the treatment of nonanastomotic strictures (NAS) has been unpromising. OBJECTIVE: We investigated the efficacy and safety of using balloon dilation and multiple biliary stents to treat NAS. DESIGN: A retrospective study. SETTING: A tertiary-care medical center. PATIENTS: Fifteen patients who were diagnosed with post-OLT NAS between January 2003 and June 2007. INTERVENTIONS: ERCP with balloon dilation and multiple stenting. MAIN OUTCOME MEASUREMENTS: Resolution, complication, and recurrence rates. RESULTS: Eleven of the 15 patients completed endoscopic treatment, of whom 9 had cholangiographic improvement, biochemical normalization, and cholestatic symptom relief (treatment success), and 1 required retransplantation (treatment failure). None of the 9 successfully treated patients experienced NAS recurrence in a mean follow-up of 17 months. Of the remaining 4 patients, 1 died of nonbiliary causes and 3 were still undergoing treatment with stents in place, of whom 2 have near-normalized total serum bilirubin and were cholestatic symptom free. LIMITATIONS: A retrospective study, small sample size, single endoscopist. CONCLUSIONS: Endoscopic treatment of NAS with balloon dilation and multiple stents appears to be safe and effective, and it may reduce the need for retransplantation because of NAS. Larger studies are still required to confirm its utility as a mainstay for treating NAS and to determine what factors are associated with endoscopic treatment success. [ABSTRACT FROM AUTHOR]

The incidence of hepatocellular carcinoma (HCC) is increasing in the United States, primarily due to hepatitis C-related liver disease. Nearly 85%-90% of patients with HCC have underlying chronic liver disease or cirrhosis. Advanced tumor burden or prohibitive hepatic dysfunction precludes operative resection in most patients with HCC. Surgical resection is a treatment option with curative intent in patients with HCC not associated with cirrhosis or in patients with well-compensated liver disease. Tumor extent and hepatic function must be assessed preoperatively to avoid postresection hepatic failure, an often fatal condition that may require urgent liver transplantation. Appropriately selected candidates for liver resection have 5-year postoperative survival rates of 40%-70%, but recurrence rates approach 70%, especially in patients with cirrhosis. For this reason, the best resection for patients with HCC and cirrhosis is orthotopic liver transplantation, which has 5-year posttransplant survival rates of 65%-80% in well-selected candidates. [ABSTRACT FROM AUTHOR]

A diagnosis of parathyroid hormone-related protein (PTH-rP)-secreting metastatic uterine epithelioid leiomyo-sarcoma was made in a 61-year-old woman with humoral hypercalcemia of malignancy. A primary uterine tumor had been removed 10 years previously, which had been associated with a short history of hypercalcemia. The original uterine tumor was diagnosed as a smooth muscle tumor of uncertain malignant potential. To the best of our knowledge, this is the first reported case of a PTH-rP-secreting uterine leiomyosarcoma. We demonstrate the dramatic changes in serum calcium, phosphorus, PTH, and PTH-rP levels after tumor resection. Extensive biochemical analysis and detailed immunohistochemical and ultrastructural characterization demonstrate several features of this tumor. [ABSTRACT FROM AUTHOR]

The history of intestinal transplantation can be traced back to the turn of the twentieth century. Although advancements have been made, the intestine still presents a greater challenge to transplantation than does that of other solid organs, experiencing higher rates of graft rejection and lower long-term survival. Increasingly, intestinal re-transplantation (re-ITx) is seen as a viable option and is now the fourth most common indication for ITx. Changes to immunosuppression protocols, technical modifications, and infectious disease monitoring have contributed to improved outcomes. The authors review the literature on re-ITx in regard to the history, management considerations, and future directions., Competing Interests: Disclosure The authors declare that they have no relevant or material financial interests that relate to the research described in this paper., (Published by Elsevier Inc.)

Background: Ischemia-reperfusion injury (IRI) is a significant clinical concern in liver transplantation, with a key influence on short-term and long-term allograft and patient survival. Myeloid cells trigger and sustain tissue inflammation and damage associated with IRI, but the mechanisms regulating these activities are unknown. To address this, we investigated the molecular characteristics of intragraft myeloid cells present in biopsy-proven IRI- and IRI+ liver transplants., Methods: RNA-sequencing was performed on 80 pre-reperfusion and post-reperfusion biopsies from 40 human recipients of liver transplantation (23 IRI+, 17 IRI-). We used transcriptional profiling and computational approaches to identify specific gene coexpression network modules correlated with functional subsets of MPO+, lysozyme+, and CD68+ myeloid cells quantified by immunohistochemistry on sequential sections from the same patient biopsies., Results: A global molecular map showed gene signatures related to myeloid activation in all patients regardless of IRI status; however, myeloid cell subsets differed dramatically in their spatial morphology and associated gene signatures. IRI- recipients were found to have a natural corticosteroid production and response profile from pre-reperfusion to post-reperfusion, particularly among monocytes/macrophages. The pre-reperfusion signature of IRI+ recipients included acute inflammatory responses in neutrophils and increased translation of adaptive immune-related genes in monocytes/macrophages coupled with decreased glucocorticoid responses. Subsequent lymphocyte activation at post-reperfusion identified transcriptional programs associated with the transition to adaptive immunity found only among IRI+ recipients., Conclusions: Myeloid subset-specific genes and related signaling pathways provide targets for the development of therapeutic strategies aimed at limiting IRI in the clinical setting of liver transplantation., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

Ischemia-reperfusion injury (IRI) during orthotopic liver transplantation (OLT) contributes to graft rejection and poor clinical outcomes. The disulfide form of high mobility group box 1 (diS-HMGB1), an intracellular protein released during OLT-IRI, induces pro-inflammatory macrophages. How diS-HMGB1 differentiates human monocytes into macrophages capable of activating adaptive immunity remains unknown. We investigated if diS-HMGB1 binds toll-like receptor (TLR) 4 and TLR9 to differentiate monocytes into pro-inflammatory macrophages that activate adaptive immunity and promote graft injury and dysfunction. Assessment of 106 clinical liver tissue and longitudinal blood samples revealed that OLT recipients were more likely to experience IRI and graft dysfunction with increased diS-HMGB1 released during reperfusion. Increased diS-HMGB1 concentration also correlated with TLR4/TLR9 activation, polarization of monocytes into pro-inflammatory macrophages, and production of anti-donor antibodies. In vitro, healthy volunteer monocytes stimulated with purified diS-HMGB1 had increased inflammatory cytokine secretion, antigen presentation machinery, and reactive oxygen species production. TLR4 inhibition primarily impeded cytokine/chemokine and costimulatory molecule programs, whereas TLR9 inhibition decreased HLA-DR and reactive oxygen species production. diS-HMGB1-polarized macrophages also showed increased capacity to present antigens and activate T memory cells. In murine OLT, diS-HMGB1 treatment potentiated ischemia-reperfusion-mediated hepatocellular injury, accompanied by increased serum alanine transaminase levels. This translational study identifies the diS-HMGB1/TLR4/TLR9 axis as potential therapeutic targets in OLT-IRI recipients., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Nonalcoholic steatohepatitis (NASH) is a severe immune-mediated stage of nonalcoholic fatty liver disease that is rapidly becoming the most common etiology requiring liver transplantation (LT), with Hispanics bearing a disproportionate burden. This study aimed to uncover the underlying immune mechanisms of the disparities experienced by Hispanic patients undergoing LT for NASH., Methods: We enrolled 164 LT recipients in our institutional review board-approved study, 33 of whom presented with NASH as the primary etiology of LT (20%), with 16 self-reported as Hispanic (48%). We investigated the histopathology of prereperfusion and postreperfusion biopsies, clinical liver function tests, longitudinal soluble cytokines via 38-plex Luminex, and immune cell phenotypes generated by prereperfusion and postreperfusion blood using 14-color flow cytometry and enzyme-linked immunosorbent assay., Results: Hispanic LT recipients transplanted for NASH were disproportionately female (81%) and disproportionately suffered poor outcomes in the first year posttransplant, including rejection (26%) and death (38%). Clinically, we observed increased pro-inflammatory and apoptotic histopathological features in biopsies, increased AST/international normalized ratio early posttransplantation, and a higher incidence of presensitization to mismatched HLA antigens expressed by the donor allograft. Experimental investigations revealed that blood from female Hispanic NASH patients showed significantly increased levels of leukocyte-attracting chemokines, innate-to-adaptive switching cytokines and growth factors, HMGB1 release, and TLR4/TLR8/TLR9/NOD1 activation, and produced a pro-inflammatory, pro-apoptotic macrophage phenotype with reduced CD14/CD68/CD66a/TIM-3 and increased CD16/CD11b/HLA-DR/CD80., Conclusions: A personalized approach to reducing immunological risk factors is urgently needed for this endotype in Hispanics with NASH requiring LT, particularly in females., (Copyright © 2023 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)

Objective: To examine liver retransplantation (ReLT) over 35 years at a single center., Background: Despite the durability of liver transplantation (LT), graft failure affects up to 40% of LT recipients., Methods: All adult ReLTs from 1984 to 2021 were analyzed. Comparisons were made between ReLTs in the pre versus post-model for end-stage liver disease (MELD) eras and between ReLTs and primary-LTs in the modern era. Multivariate analysis was used for prognostic modeling., Results: Six hundred fifty-four ReLTs were performed in 590 recipients. There were 372 pre-MELD ReLTs and 282 post-MELD ReLTs. Of the ReLT recipients, 89% had one previous LT, whereas 11% had ≥2. Primary nonfunction was the most common indication in the pre-MELD era (33%) versus recurrent disease (24%) in the post-MELD era. Post-MELD ReLT recipients were older (53 vs 48, P = 0.001), had higher MELD scores (35 vs 31, P = 0.01), and had more comorbidities. However, post-MELD ReLT patients had superior 1, 5, and 10-year survival compared with pre-MELD ReLT (75%, 60%, and 43% vs 53%, 43%, and 35%, respectively, P < 0.001) and lower in-hospital mortality and rejection rates. Notably, in the post-MELD era, the MELD score did not affect survival. We identified the following risk factors for early mortality (≤12 months after ReLT): coronary artery disease, obesity, ventilatory support, older recipient age, and longer pre-ReLT hospital stay., Conclusions: This represents the largest single-center ReLT report to date. Despite the increased acuity and complexity of ReLT patients, post-MELD era outcomes have improved. With careful patient selection, these results support the efficacy and survival benefit of ReLT in an acuity-based allocation environment., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

HCC recurrence following liver transplantation (LT) is highly morbid and occurs despite strict patient selection criteria. Individualized prediction of post-LT HCC recurrence risk remains an important need. Clinico-radiologic and pathologic data of 4981 patients with HCC undergoing LT from the US Multicenter HCC Transplant Consortium (UMHTC) were analyzed to develop a REcurrent Liver cAncer Prediction ScorE (RELAPSE). Multivariable Fine and Gray competing risk analysis and machine learning algorithms (Random Survival Forest and Classification and Regression Tree models) identified variables to model HCC recurrence. RELAPSE was externally validated in 1160 HCC LT recipients from the European Hepatocellular Cancer Liver Transplant study group. Of 4981 UMHTC patients with HCC undergoing LT, 71.9% were within Milan criteria, 16.1% were initially beyond Milan criteria with 9.4% downstaged before LT, and 12.0% had incidental HCC on explant pathology. Overall and recurrence-free survival at 1, 3, and 5 years was 89.7%, 78.6%, and 69.8% and 86.8%, 74.9%, and 66.7%, respectively, with a 5-year incidence of HCC recurrence of 12.5% (median 16 months) and non-HCC mortality of 20.8%. A multivariable model identified maximum alpha-fetoprotein (HR = 1.35 per-log SD, 95% CI,1.22-1.50, p < 0.001), neutrophil-lymphocyte ratio (HR = 1.16 per-log SD, 95% CI,1.04-1.28, p < 0.006), pathologic maximum tumor diameter (HR = 1.53 per-log SD, 95% CI, 1.35-1.73, p < 0.001), microvascular (HR = 2.37, 95%-CI, 1.87-2.99, p < 0.001) and macrovascular (HR = 3.38, 95% CI, 2.41-4.75, p < 0.001) invasion, and tumor differentiation (moderate HR = 1.75, 95% CI, 1.29-2.37, p < 0.001; poor HR = 2.62, 95% CI, 1.54-3.32, p < 0.001) as independent variables predicting post-LT HCC recurrence (C-statistic = 0.78). Machine learning algorithms incorporating additional covariates improved prediction of recurrence (Random Survival Forest C-statistic = 0.81). Despite significant differences in European Hepatocellular Cancer Liver Transplant recipient radiologic, treatment, and pathologic characteristics, external validation of RELAPSE demonstrated consistent 2- and 5-year recurrence risk discrimination (AUCs 0.77 and 0.75, respectively). We developed and externally validated a RELAPSE score that accurately discriminates post-LT HCC recurrence risk and may allow for individualized post-LT surveillance, immunosuppression modification, and selection of high-risk patients for adjuvant therapies., (Copyright © 2023 American Association for the Study of Liver Diseases.)

Background and Aims: The sensitivity of current surveillance methods for detecting early-stage hepatocellular carcinoma (HCC) is suboptimal. Extracellular vesicles (EVs) are promising circulating biomarkers for early cancer detection. In this study, we aim to develop an HCC EV-based surface protein assay for early detection of HCC., Approach and Results: Tissue microarray was used to evaluate four potential HCC-associated protein markers. An HCC EV surface protein assay, composed of covalent chemistry-mediated HCC EV purification and real-time immuno-polymerase chain reaction readouts, was developed and optimized for quantifying subpopulations of EVs. An HCC EV ECG score, calculated from the readouts of three HCC EV subpopulations ( E pCAM + CD63 + , C D147 + CD63 + , and G PC3 + CD63 + HCC EVs), was established for detecting early-stage HCC. A phase 2 biomarker study was conducted to evaluate the performance of ECG score in a training cohort ( n  = 106) and an independent validation cohort ( n  = 72).Overall, 99.7% of tissue microarray stained positive for at least one of the four HCC-associated protein markers (EpCAM, CD147, GPC3, and ASGPR1) that were subsequently validated in HCC EVs. In the training cohort, HCC EV ECG score demonstrated an area under the receiver operating curve (AUROC) of 0.95 (95% confidence interval [CI], 0.90-0.99) for distinguishing early-stage HCC from cirrhosis with a sensitivity of 91% and a specificity of 90%. The AUROCs of the HCC EV ECG score remained excellent in the validation cohort (0.93; 95% CI, 0.87-0.99) and in the subgroups by etiology (viral: 0.95; 95% CI, 0.90-1.00; nonviral: 0.94; 95% CI, 0.88-0.99)., Conclusion: HCC EV ECG score demonstrated great potential for detecting early-stage HCC. It could augment current surveillance methods and improve patients' outcomes., (Copyright © 2023 American Association for the Study of Liver Diseases.)

Although glycogen synthase kinase β (Gsk3β) has been shown to regulate tissue inflammation, whether and how it regulates inflammation resolution versus inflammation activation is unclear. In a murine liver, partial warm ischemia/reperfusion injury (IRI) model, we found that Gsk3β inhibitory phosphorylation increased at both the early-activation and late-resolution stages of the disease. Myeloid Gsk3β deficiency not only alleviated liver injuries, it also facilitated the restoration of liver homeostasis. Depletion of Kupffer cells prior to the onset of liver ischemia diminished the differences between the WT and Gsk3β-KO mice in the activation of liver IRI. However, the resolution of liver IRI remained accelerated in Gsk3β-KO mice. In CD11b-DTR mice, Gsk3β-deficient BM-derived macrophages (BMMs) facilitated the resolution of liver IRI as compared with WT cells. Furthermore, Gsk3β deficiency promoted the reparative phenotype differentiation in vivo in liver-infiltrating macrophages and in vitro in BMMs. Gsk3 pharmacological inhibition promoted the resolution of liver IRI in WT, but not myeloid MerTK-deficient, mice. Thus, Gsk3β regulates liver IRI at both activation and resolution stages of the disease. Gsk3 inactivation enhances the proresolving function of liver-infiltrating macrophages in an MerTK-dependent manner.

NAFLD will soon be the most common indication for liver transplantation (LT). In NAFLD, HCC may occur at earlier stages of fibrosis and present with more advanced tumor stage, raising concern for aggressive disease. Thus, adult LT recipients with HCC from 20 US centers transplanted between 2002 and 2013 were analyzed to determine whether NAFLD impacts recurrence-free post-LT survival. Five hundred and thirty-eight (10.8%) of 4981 total patients had NAFLD. Patients with NAFLD were significantly older (63 vs. 58, p<0.001), had higher body mass index (30.5 vs. 27.4, p<0.001), and were more likely to have diabetes (57.3% vs. 28.8%, p<0.001). Patients with NAFLD were less likely to receive pre-LT locoregional therapy (63.6% vs. 72.9%, p<0.001), had higher median lab MELD (15 vs. 13, p<0.001) and neutrophil-lymphocyte ratio (3.8 vs. 2.9, p<0.001), and were more likely to have their maximum pre-LT alpha fetoprotein at time of LT (44.1% vs. 36.1%, p<0.001). NAFLD patients were more likely to have an incidental HCC on explant (19.4% vs. 10.4%, p<0.001); however, explant characteristics including tumor differentiation and vascular invasion were not different between groups. Comparing NAFLD and non-NAFLD patients, the 1, 3, and 5-year cumulative incidence of recurrence (3.1%, 9.1%, 11.5% vs. 4.9%, 10.1%, 12.6%, p=0.36) and recurrence-free survival rates (87%, 76%, and 67% vs. 87%, 75%, and 67%, p=0.97) were not different. In competing risks analysis, NAFLD did not significantly impact recurrence in univariable (HR: 0.88, p=0.36) nor in adjusted analysis (HR: 0.91, p=0.49). With NAFLD among the most common causes of HCC and poised to become the leading indication for LT, a better understanding of disease-specific models to predict recurrence is needed. In this NAFLD cohort, incidental HCCs were common, raising concerns about early detection. However, despite less locoregional therapy and high neutrophil-lymphocyte ratio, explant tumor characteristics and post-transplant recurrence-free survival were not different compared to non-NAFLD patients., (Copyright © 2022 American Association for the Study of Liver Diseases.)

This study investigated the effect of low-dose aspirin in primary adult liver transplantation (LT) on acute cellular rejection (ACR) as well as arterial patency rates. The use of low-dose aspirin after LT is practiced by many transplant centers to minimize the risk of hepatic artery thrombosis (HAT), although solid recommendations do not exist. However, aspirin also possesses potent anti-inflammatory properties and might mitigate inflammatory processes after LT, such as rejection. Therefore, we hypothesized that the use of aspirin after LT has a protective effect against ACR. This is an international, multicenter cohort study of primary adult deceased donor LT. The study included 17 high-volume LT centers and covered the 3-year period from 2013 to 2015 to allow a minimum 5-year follow-up. In this cohort of 2365 patients, prophylactic antiplatelet therapy with low-dose aspirin was administered in 1436 recipients (61%). The 1-year rejection-free survival rate was 89% in the aspirin group versus 82% in the no-aspirin group (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.63-0.94; p = 0.01). The 1-year primary arterial patency rates were 99% in the aspirin group and 96% in the no-aspirin group with an HR of 0.23 (95% CI, 0.13-0.40; p < 0.001). Low-dose aspirin was associated with a lower risk of ACR and HAT after LT, especially in the first vulnerable year after transplantation. Therefore, low-dose aspirin use after primary LT should be evaluated to protect the liver graft from ACR and to maintain arterial patency., (© 2022 The Authors. Liver Transplantation published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)

Immunosuppression withdrawal can be safely performed in select liver transplantation recipients, but the long-term outcomes and sustainability of tolerance have not been well studied. We completed a 10-year prospective, observational study of 18 pediatric liver transplantation recipients with operational tolerance to (1) assess the sustainability of tolerance over time, (2) compare the clinical characteristics of patients who maintained versus lost tolerance, (3) characterize liver histopathology findings in surveillance liver biopsies; and (4) describe immunologic markers in patients with tolerance. Comparator patients from two clinical phenotype groups termed "stable" and "nontolerant" patients were used as controls. Of the 18 patients with operational tolerance, the majority of patients were males (n = 14, 78%) who were transplanted for cholestatic liver disease (n = 12, 67%). Median age at transplantation was 1.9 (range, 0.6-8) years. Median time after transplantation that immunosuppression had been discontinued was 13.1 (range, 2.9-22.1) years. As many as 11 (61%) maintained tolerance for a median of 10.4 (range, 1.9-22.1) years, whereas 7 (39%) lost tolerance after a median of 3.2 (range, 1.5-18.6) years. Populations of T regulatory cells (%CD4 + CD25 hi CD127 lo ) were significantly higher in patients with tolerance (p = 0.02). Our results emphasize that spontaneous operational tolerance is a dynamic and nonpermanent state. It is therefore essential for patients who are clinically stable off immunosuppression to undergo regular follow-up and laboratory monitoring, as well as surveillance biopsies to rule out subclinical rejection., (© 2022 American Association for the Study of Liver Diseases.)

There are parallels between the history of Enhanced Recovery after Surgery (ERAS) and liver transplantation. Both have been established and advanced by innovative individuals, often going against perceived wisdom and convention. Liver transplantation has traditionally been considered too complex for ERAS pathways, despite a small number of trials showing them to be both safe and of benefit. To date, there are very few randomized controlled trials and cohort studies publishing outcomes on liver transplant patients enrolled in comprehensive ERAS pathways. To progress our field, the 2022 International Liver Transplantation Society's Consensus Conference has created expert panels to analyze the evidence in 32 domains of the liver transplantation pathway using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach to generate expert recommendations. These recommendations will be voted on by the international community to gain consensus using the Danish model, and create the ERAS4OLT.org Enhanced Recovery after Liver Transplantation Pathway., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Importance: National guidelines on transplant selection have adopted successful downstaging to within Milan criteria (MC) as a viable option for the treatment of hepatocellular carcinoma (HCC) before liver transplant (LT). Recurrence of HCC after LT carries a poor prognosis, and treatment modalities remain challenging., Objective: To establish the 10-year outcomes of patients with HCC after LT in a large, multicenter US study based on individual data; provide robust data on the long-term role of downstaging; and evaluate the association of treatment modalities with postrecurrence survival., Design, Setting, and Participants: In this cohort study, a retrospective, multicenter analysis of prospectively collected data was conducted for 2645 adults who had undergone LT for HCC at 5 US academic centers between January 2001 and December 2015. The analysis was performed from May 2019 through June 2021. Outcomes of 341 patients whose disease was downstaged to within MC were compared with those in 2122 patients whose disease was always within MC and 182 patients whose disease was not downstaged. The associations of tumor and treatment factors on postrecurrence survival were analyzed using Cox proportional hazards regression and multivariable logistic regression models., Main Outcomes and Measures: The primary outcome was overall survival for the whole cohort and according to downstaging status. Secondary outcomes were time to recurrence, recurrence-free survival, and recurrence after specific post-LT therapies., Results: Of the 2645 patients studied, the median age was 59.9 years (IQR, 54.7-64.7 years). The majority of the patients were men (2028 [76.7%] vs 617 [23.3%] women). The 10-year post-LT survival and recurrence rates were, respectively, 52.1% and 20.6% among those whose disease was downstaged; 61.5% and 13.3% in those always within MC; and 43.3% and 41.1% in those whose disease was not downstaged. Independent variables associated with downstaging failure were tumor size greater than 7 cm at diagnosis (OR, 2.62; 95% CI, 1.20-5.75; P = .02), more than 3 tumors at diagnosis (OR, 2.34; 95% CI, 1.22-4.50; P = .01), and α-fetoprotein response of at least 20 ng/mL with less than 50% improvement from maximum α-fetoprotein before LT (OR, 1.99; 95% CI, 1.14-3.46; P = .02). Surgically treated patients with recurrent HCC differed in clinicopathologic characteristics and had improved 5-year postrecurrence survival rates (31.6% vs 7.3%; P < .001)., Conclusions and Relevance: In a large, multicenter cohort of patients with HCC successfully downstaged to within MC, 10-year post-LT outcomes were excellent, validating national downstaging policies and showing a clear utility benefit for LT prioritization decision making. Surgical management of HCC recurrence after LT was associated with improved survival in well-selected patients and should be pursued, if feasible.

Liver transplantation (LT) for cholangiocarcinoma (CCA) remains limited to a small number of centers. Although the role of neoadjuvant therapy (NAT) has been explored over time, an in-depth analysis of NAT strategies remains limited. Furthermore, controversy exists regarding acceptable tumor size during patient selection for LT. This study explores the impact of era, tumor size, and NAT strategy on LT outcomes for CCA. We conducted a retrospective review of 53 patients with CCA treated with LT from 1985 to 2019; 19 hilar CCA (hCCA) and 30 intrahepatic CCA (iCCA) were included. The relative contributions of varying NAT (neoadjuvant chemotherapy [NAC], neoadjuvant local therapy [NALT], and combined NAC and NALT [NACLT]) as well as the implication of tumor size and era were analyzed. The primary endpoint was overall survival (OS). Compared with the old era (1985-2007), 5-year OS in patients who underwent LT in the recent era (2008-2019) showed a superior trend. The 5-year OS from initial treatment in patients receiving NACLT for hCCA and iCCA were 88% and 100% versus 9% and 41% in patients without it, respectively (P = 0.01 for hCCA; P = 0.02 for iCCA), whereas NAC or NALT alone did not show significant differences in OS versus no NAT (P > 0.05). Although 33 patients had large-size tumors (hCCA ≥ 30 mm, n = 12, or iCCA ≥ 50 mm, n = 21), tumor size had no impact on survival outcomes. Outcomes of LT for CCA seem to have improved over time. Multimodal NAT is associated with improved survival in LT for both iCCA and hCCA regardless of tumor size., (Copyright © 2021 American Association for the Study of Liver Diseases.)

Fractional flow reserve (FFR) determines the functional significance of epicardial stenoses assuming negligible venous pressure (P v ) and microvascular resistance. However, these assumptions may be invalid in end-stage liver disease (ESLD) because of fluctuating P v and vasodilation. Accordingly, all patients with ESLD who underwent right-sided cardiac catheterization and coronary angiography with FFR as part of their orthotopic liver transplantation evaluation between 2013 and 2018 were included in the present study. Resting mean distal coronary pressure (P d )/mean aortic pressure (P a ), FFR, and P v were measured. FFR accounting for P v (FFR - P v ) was defined as (P d  - P v )/(P a  - P v ). The hyperemic effect of adenosine was defined as resting P d /P a  - FFR. The primary outcome was all-cause mortality at 1 year. In 42 patients with ESLD, 49 stenoses were interrogated by FFR (90% were <70% diameter stenosis). Overall, the median model for ESLD score was 16.5 (10.8 to 25.5), FFR was 0.87 (0.81 to 0.94), P v was 8 mm Hg (4 to 14), FFR-P v was 0.86 (0.80 to 0.94), and hyperemic effect of adenosine was 0.06 (0.02 to 0.08). FFR-P v led to the reclassification of 1 stenosis as functionally significant. There was no significant correlation between the median model for ESLD score and the hyperemic effect of adenosine (R = 0.10). At 1 year, 13 patients had died (92% noncardiac in etiology), and patients with FFR ≤0.80 had significantly higher all-cause mortality (73% vs 17%, p = 0.001. In conclusion, in patients with ESLD who underwent orthotopic liver transplantation evaluation, P v has minimal impact on FFR, and the hyperemic effect of adenosine is preserved. Furthermore, even in patients with the predominantly angiographically-intermediate disease, FFR ≤0.80 was an independent predictor of all-cause mortality., Competing Interests: Disclosures Dr. Parikh reports research support from the American Heart Association, consulting fees from Abbott Vascular, and serving on the scientific advisory board (minor equity interest) of Stallion Cardio, DocVocate, and HeartCloud., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Frailty has been implicated as a negative predictor of Liver Transplant (LT) outcomes. However, an understanding of changes in patient muscle mass peri-LT, and their effect in high-acuity patients remains lacking. We examined the impact of perioperative muscle mass changes (ΔSMI) on high-acuity (MELD ≥35) LT recipients., Materials and Methods: Skeletal muscle index (SMI) was calculated using CT imaging. Patients were divided into two groups, based on severity of peri-operative SMI decrease. LT recipients with chronic end-stage liver disease, MELD ≥35, and abdominal CT ≤30 days prior, and 30-90 days post LT were included. [1011 adult LT recipients reviewed, 2012-2018]., Results: Of 1011 patients reviewed, 88 met inclusion criteria (median MELD 41.1). The median ΔSMI was -5.0 (-29.4 - +21.1 cm 2 /m 2 ) (fig A). Patients were classified into two groups: ΔSMI<-5.0 (median ΔSMI: -0.4, n = 44) and ΔSMI>-5.0 (median ΔSMI: -9.2, n = 44). Recipients with ΔSMI<-5.0 had higher pre-LT SMI (35.4 versus 31.2 cm 2 /m 2 , P <0.001) and lower post-LT SMI (26.0 versus 30.8 cm 2 /m 2 , P <0.001). The ΔSMI<-5.0 group had higher early allograft dysfunction (40.9 versus 20.5%, P = 0.037), and inferior patient and graft survival (P = 0.015, 0.017, respectively). Multivariate analysis identified ΔSMI<-5.0 (HR: 2.938, P = 0.048), long cold-ischemia time (≥9h, HR: 7.332, P = 0.008), HCV (HR: 5.614, p = 0.001), and tracheostomy after LT (HR:9.218, P <0.001) as negative prognostic factors for patient survival ., Conclusions: Progressive perioperative sarcopenic deterioration was associated with inferior patient and graft survival in high acuity LT. These findings may guide pre and post-operative patient care and rehabilitation efforts in this challenging patient population., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Numerous studies in hepatocellular carcinoma (HCC) have proposed tissue-based gene signatures for individualized prognostic assessments. Here, we develop a novel circulating tumor cell (CTC)-based transcriptomic profiling assay to translate tissue-based messenger RNA (mRNA) signatures into a liquid biopsy setting for noninvasive HCC prognostication. The HCC-CTC mRNA scoring system combines the NanoVelcro CTC Assay for enriching HCC CTCs and the NanoString nCounter platform for quantifying the HCC-CTC Risk Score (RS) panel in enriched HCC CTCs. The prognostic role of the HCC-CTC RS was assessed in The Cancer Genome Atlas (TCGA) HCC cohort (n = 362) and validated in an independent clinical CTC cohort (n = 40). The HCC-CTC RS panel was developed through our integrated data analysis framework of 8 HCC tissue-based gene signatures and identified the top 10 prognostic genes (discoidin domain receptor tyrosine kinase 1 [DDR1], enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase [EHHADH], androgen receptor [AR], lumican [LUM], hydroxysteroid 17-beta dehydrogenase 6[HSD17B6], prostate transmembrane protein, androgen induced 1 [PMEPA1], tsukushi, small leucine rich proteoglycan [TSKU], N-terminal EF-hand calcium binding protein 2 [NECAB2], ladinin 1 [LAD1], solute carrier family 27 member 5 [SLC27A5]) highly expressed in HCC with low expressions in white blood cells. The panel accurately discriminated overall survival in TCGA HCC cohort (hazard ratio [HR], 2.0; 95% confidence interval [CI], 1.4-2.9). The combined use of the scoring system and HCC-CTC RS panel successfully distinguished artificial blood samples spiked with an aggressive HCC cell type, SNU-387, from those spiked with PLC/PRF/5 cells (P = 0.02). In the CTC validation cohort (n = 40), HCC-CTC RS remained an independent predictor of survival (HR, 5.7; 95% CI, 1.5-21.3; P = 0.009) after controlling for Model for End-Stage Liver Disease score, Barcelona Clinic Liver Cancer stage, and CTC enumeration count. Our study demonstrates a novel interdisciplinary approach to translate tissue-based gene signatures into a liquid biopsy setting. This noninvasive approach will allow real-time disease profiling and dynamic prognostication of HCC., (Copyright © 2021 American Association for the Study of Liver Diseases.)

Background: Sarcopenia has gained momentum as a potential risk-stratification tool in liver transplantation (LT). While LT recipients recently have more advanced end-stage liver disease, the impact of sarcopenia in high acuity recipients with a high model for end-stage liver disease (MELD) score remains unclear., Methods: We retrospectively assessed sarcopenia by calculating skeletal muscle index (SMI) from cross-sectional area at third lumbar vertebra (cm 2 ) and height (m 2 ) in 296 patients with a CT ≤ 30 days prior to LT. Sex-specific SMI cut-offs were developed, and its impact was assessed in patients with MELD ≥ 35., Results: In patients with MELD ≥ 35 (n = 217), men with a SMI < 30 cm 2 /m 2 had significantly higher rates of bacteremia (P = .021) and a longer hospital stay (P < .001). Women with a SMI < 34 cm 2 /m 2 had a longer hospital stay (P = .032). There were no relationships between SMI and survival in men and women with MELD ≥ 35., Conclusions: This series examined sarcopenia with a focus on high MELD patients. Although decreased SMI contributed to higher post-LT hospital stay, it did not impact patient survival, suggesting that while SMI alone may not aid in patient selection for LT, it certainly may guide perioperative care-planning in this challenging patient population., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: The aims of the present study were to identify independent risk factors for conduit occlusion, compare outcomes of different AC placement sites, and investigate whether postoperative platelet antiaggregation is protective., Background: Arterial conduits (AC) in liver transplantation (LT) offer an effective rescue option when regular arterial graft revascularization is not feasible. However, the role of the conduit placement site and postoperative antiaggregation is insufficiently answered in the literature., Study Design: This is an international, multicenter cohort study of adult deceased donor LT requiring AC. The study included 14 LT centers and covered the period from January 2007 to December 2016. Primary endpoint was arterial occlusion/patency. Secondary endpoints included intra- and perioperative outcomes and graft and patient survival., Results: The cohort was composed of 565 LT. Infrarenal aortic placement was performed in 77% of ACs whereas supraceliac placement in 20%. Early occlusion (≤30 days) occurred in 8% of cases. Primary patency was equivalent for supraceliac, infrarenal, and iliac conduits. Multivariate analysis identified donor age >40 years, coronary artery bypass, and no aspirin after LT as independent risk factors for early occlusion. Postoperative antiaggregation regimen differed among centers and was given in 49% of cases. Graft survival was significantly superior for patients receiving aggregation inhibitors after LT., Conclusion: When AC is required for rescue graft revascularization, the conduit placement site seems to be negligible and should follow the surgeon's preference. In this high-risk group, the study supports the concept of postoperative antiaggregation in LT requiring AC., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Although the use of extended criteria donor (ECD) liver allografts has gained momentum as a potential method by which to expand the donor pool, their use largely remains relegated to low acuity liver transplant (LT) recipients. Thus, we sought to examine whether such grafts also have utility in high acuity (Model for End-Stage Liver Disease [MELD] ≥ 35) recipients., Study Design: Extended criteria donors were defined as donor age > 60 years, hepatitis C virus positive donor, split livers, livers with cold ischemia time > 12 h, donor after cardiac death livers, or having macrosteatosis > 30%. Outcomes were compared between standard liver (SL) and ECD grafts in recipients with MELD ≥ 35., Results: Of 225 patients, 46 (20.4%) received an ECD liver and 179 (79.6%) received a SL. Extended criteria donor graft recipients had significantly higher levels of post-LT maximal transaminases and rate of early allograft dysfunction. Nonetheless, high acuity ECD graft recipients had similar short- and long-term patient survival compared to SL recipients, with 1-,3-, and 5-year survivals of 86.9%, 82.3%, 79.3% and 86.9%, 80.5%, and 75.4%, respectively ( P = .674). There were also no significant differences in graft survival or rejection-free survival between the 2 groups., Conclusion: The lack of inferior patient/graft survival among high acuity ECD graft recipients suggests that ECD livers present a viable method by which to expand the donor pool for this group of patients.

Background and Aims: Environmentally triggered chronic liver inflammation can cause collagen deposits, whereas early stages of fibrosis without any specific symptoms could hardly be detectable. We hypothesized that some of the human donor grafts in clinical liver transplantation (LT) might possess unrecognizable fibrosis, affecting their susceptibility to LT-induced stress and hepatocellular damage. This retrospective study aimed to assess the impact of occult hepatic fibrosis on clinical LT outcomes., Approach and Results: Human (194) donor liver biopsies were stained for collagen with Sirius red, and positive areas (Sirius red-positive area; SRA) were measured. The body mass index, aspartate aminotransferase/alanine aminotransferase ratio, diabetes score was calculated using 962 cases of the donor data at the procurement. LT outcomes, including ischemia-reperfusion injury (IRI), early allograft dysfunction (EAD), and survival rates, were analyzed according to SRA and BARD scores. With the median SRA in 194 grafts of 9.4%, grafts were classified into low-SRA (<15%; n = 140) and high-SRA (≥15%; n = 54) groups. Grafts with high SRA suffered from higher rates of IRI and EAD (P < 0.05) as compared to those with low SRA. Interestingly, high SRA was identified as an independent risk factor for EAD and positively correlated with the donor BARD score. When comparing low-BARD (n = 692) with high-BARD (n = 270) grafts in the same period, those with high BARD showed significantly higher post-LT transaminase levels and higher rates of IRI and EAD., Conclusions: These findings from the largest clinical study cohort to date document the essential role of occult collagen deposition in donor livers on LT outcomes. High-SRA and donor BARD scores correlated with an increased incidence of hepatic IRI and EAD in LT recipients. This study provides the rationale for in-depth and prospective assessment of occult fibrosis for refined personalized LT management., (© 2021 The Authors. Hepatology published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)

Background and Aims: Liver ischemia reperfusion injury (IRI) remains an unresolved clinical problem. This study dissected roles of liver-resident macrophage Kupffer cells (KCs), with a functional focus on efferocytosis receptor T-cell immunoglobulin and mucin domain-containing protein-4 (TIM-4), in both the activation and resolution of IRI in a murine liver partial warm ischemia model., Approach and Results: Fluorescence-activated cell sorting results showed that TIM-4 was expressed exclusively by KCs, but not infiltrating macrophages (iMФs), in IR livers. Anti-TIM-4 antibody depleted TIM-4 + macrophages in vivo, resulting in either alleviation or deterioration of liver IRI, which was determined by the repopulation kinetics of the KC niche with CD11b + macrophages. To determine the KC-specific function of TIM-4, we reconstituted clodronate-liposome-treated mice with exogenous wild-type or TIM-4-deficient KCs at either 0 hour or 24 hours postreperfusion. TIM-4 deficiency in KCs resulted in not only increases in the severity of liver IRI (at 6 hours postreperfusion), but also impairment of the inflammation resolution (at 7 days postreperfusion). In vitro analysis revealed that TIM-4 promoted KC efferocytosis to regulate their Toll-like receptor response by up-regulating IL-10 and down-regulating TNF-α productions., Conclusions: TIM-4 is critical for KC homeostatic function in both the activation and resolution of liver IRI by efferocytosis., (© 2021 by the American Association for the Study of Liver Diseases.)

Background: A major discrepancy between clinical and most experimental settings of liver ischemia-reperfusion injury (IRI) is the allogenicity., Methods: In the current study, we first established a murine model of allogeneic orthotopic liver transplantation with extended cold ischemia time (18 h). Roles of CD4 T cells in the pathogenesis of IRI in liver allografts were determined using a depleting anti-CD4 antibody. The clinical relevance of CD4 as a marker of liver IRI was analyzed retrospectively in 55 liver transplant patients., Results: CD4 depletion in both donors and recipients resulted in the most effective protection of liver allografts from IRI, as measured by serum transaminase levels and liver histology. CD4 depletion inhibited IR-induced intragraft neutrophil/macrophage infiltration and proinflammatory gene expressions. Quantitative reverse-transcriptase polymerase chain reaction analysis of human liver biopsies (2 h postreperfusion) revealed that posttransplant, rather than pretransplant, CD4 transcript levels correlated positively with proinflammatory gene expression profile. When we divided patients into subgroups according to intragraft CD4 levels, the high CD4 cohort developed a more severe hepatocellular damage than that with low CD4 levels., Conclusions: CD4 T cells play a key pathogenic role in IRI of allogeneic liver transplants, and intragraft CD4 levels in the early postreperfusion phase may serve as a potential biomarker and therapeutic target to ameliorate liver IRI and improve orthotopic liver transplantation outcomes., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)