Successful Liver Transplantation Research Articles

Successful Liver Transplant From a Donor With Sickle Cell Disease.

Sickle cell disease patients have routinely been excluded from liver transplant donation due to patients historically manifesting liver disease themselves. Marginal donors have become increasingly more welcome given organ shortage. Our institution performed a liver transplant in a recipient with cholangiocarcinoma using a sickle cell disease donor liver. Postoperatively, patient progressed well and is now cancer free. Pathology indicated sickle cells, and hemosiderin present at time of transplant had largely resolved by repeat biopsy on postoperative day 5. We conclude that sickle cell disease patients should be considered as donors for liver transplant in the appropriate setting.

Multidisciplinary approach to the treatment of a patient with hepatocellular carcinoma against the background of liver cirrhosis of viral (hepatitis C) etiology. Cinical case

The article presents a clinical case of a multidisciplinary approach to the treatment of 55‑years‑old patient with hepatocellular carcinoma (HCC) against the background of liver cirrhosis of viral (hepatitis C) etiology. A focal liver lesion was accidentally detected during an ultrasound examination in an asymptomatic patient. Further radiological studies (CT and MRI of the liver with contrast) revealed numerous focal lesions of the liver against the background of its cirrhotic alterations. One of the foci in S7 with dimensions 62x68 mm, had LIRADS 5 signs, so it did not require histological verification. According to the Barcelona guidelines, the patient met criteria for advanced HCC (stage B). Treatment options in this case were liver transplantation or locoregional therapy to reduce the HCC stage. The preserved portal blood flow and the preserved functional status of the patient made it possible to conduct successful transarterial chemoembolisation of the focus in S7. After two months, radiological control recorded stabilization of the focus with necrosis and absence of distant metastatic lesions. Moreover, patient had a recurrence of viral hepatitis C, which required administration of the scheme sofosbuvir + glecaprevir/pibrentasvir. After reviewing the patient’s clinical status and evaluating his radiological and serological dynamics, the possibility of liver transplantation was considered. On April 20, 2023, a successful orthotopic liver transplantation was performed. Pathomorphological findings confirmed HCC G2 in the S7 focus. Three months after transplantation, the patient developed a clinical picture of acute cellular rejection of mild severity, which was confirmed by pathomorphological examination. Appropriate correction of immunosuppressive therapy stabilized the patient’s clinical condition and liver function tests. In the future, the patient needs dynamic monitoring with careful control of laboratory parameters and radiological examinations.

Downstaging Hepatocellular Carcinoma with Checkpoint Inhibitor Therapy Improves Access to Curative Liver Transplant.

Liver transplantation is curative for hepatocellular carcinoma (HCC). Checkpoint inhibitor therapy (CPIT) has been used in unresectable HCC, but recent advances have demonstrated CPIT as an innovative method of downstaging advanced HCC with the caveat that CPIT prior to transplantation has risks including irreversible graft rejection. We report the outcomes of Mayo Clinic Arizona patients who underwent downstaging with CPIT. This retrospective chart review was conducted for Mayo Clinic Arizona patients who were diagnosed with HCC who underwent downstaging with CPIT with the goal of meeting criteria for transplantation. We present nine cases with HCC outside Milan who underwent CPIT. Four received a transplant; one was delisted due to his exceptional therapeutic response. All received liver-directed therapy. Peak alpha-fetoprotein pre-CPIT ranged from 8-29,523ng/mL, which decreased to 2.2-19.6ng/mL on CPIT. CPIT included atezolizumab/bevacizumab, ipilimumab/nivolumab, nivolumab, and pembrolizumab; one patient received two regimens. CPIT was held prior to transplant at a median of 3months. Three patients received methylprednisolone for immunosuppression induction; one received thymoglobulin. One patient developed acute cellular rejection at 5weeks, 9weeks, and 5months post-transplant; given the late onset, these were not attributed to CPIT and were successfully treated. During an average follow-up of 16.5months, no tumor recurrence has occurred. We describe nine patients with HCC outside Milan with inadequate response with liver-directed therapy, who achieved marked responses with CPIT, allowing for consideration of successful liver transplantation. Our case series supports the consideration of locoregional therapies and CPIT for downstaging to within transplant criteria.

A58 UTILIZATION OF HYPOXIA-TOLERANT ORGANISMS AS A MODEL IN THE STUDY OF ISCHEMIC-REPERFUSION INJURY IN TRANSPLANT HEPATOLOGY

Abstract Background Ischemic-reperfusion injury (IRI) is a barrier to successful liver transplantation. This complex process is initiated by an episode of hypoxia and decreased adenosine triphosphate (ATP) production. Mammalian hepatocytes are susceptible to prolonged hypoxia and may experience irreversible damage with ATP depletion. Yet, facultative anaerobes have developed physiological hepatoprotective strategies to tolerate hypoxic stress. The painted turtle (Chrysemys picta belli) and the common goldfish (Carassius auratus) are able to survive under severe hypoxia for weeks to months. Aims Introducing hypoxia-tolerant organisms as a suitable animal model for studying IRI in transplant hepatology. Methods A comprehensive search of PubMed, OVID, CINAHL, and Cochrane databases up to May 2023 was conducted to identify all studies reporting experimental evidence and hepatoprotective pathways in hypoxia-tolerant organisms (HTOs). Each article was qualitatively assessed. The primary focus was on cell death, intracellular ion gradient, mitochondrial function, and reactive oxygen species (ROS) with hypoxia and IRI. Results HTOs have increased glycogen storage with a greater ATP yield from anaerobic metabolism (glycolysis). Approximately 15-30% of liver mass in HTOs is composed of glycogen which is massive compared to 5-6% in mammals. Turtle isolated hepatocytes can tolerate 10 hours of anoxia by reducing cellular metabolic demand by 90% through decreased protein synthesis and ion channel activity. Goldfish hepatocytes can tolerate 6 hours of anoxia via similar strategies. In mammals, mitochondria undergo depolarization, Ca2+ efflux, cellular swelling, and apoptosis with anoxia. Yet, a depolarized mitochondrial membrane potential is regulated to provide cellular protection in HTOs. The ability to preserve mitochondrial function and electrochemical gradients with oxygen lack is an important contributor to cellular survival. Even in mammalian hepatocytes, if the mitochondrial integrity is maintained, cells are better able to tolerate ischemic insults. Finally, formation of radicals with reperfusion leads to hepatocyte apoptosis and necrosis in the mammalian model. Meanwhile, regulated ROS levels in turtles and goldfish cells, prevent cell death and IRI. Conclusions IRI is of significant interest in transplant hepatology. Although extremely valuable, the traditional mammalian models are vulnerable to hypoxia. Meanwhile, HTOs have undergone years of adaptation with thousands of genes dedicated to hypoxia tolerance. Utilizing these organisms can provide a broader understanding of IRI and avoid irreversible tissue damage in transplant hepatology. Funding Agencies CIHR

What is the crux of successful living-donor liver transplantation for recipients aged 70 and beyond?

There is limited evidence regarding the feasibility of living-donor liver transplantation (LDLT) for patients aged over 70. The aims of this study were to assess postoperative outcomes in elderly recipients and to ascertain the potential feasibility and acceptability of LDLT. Data were collected from 762 recipients, including 26 in the elderly group (aged ≥70) and 736 in the younger group (aged <70), and reviewed even by propensity score matching (PSM). No significant differences were observed in the frequency of postoperative complications between the two groups. Additionally, both groups exhibited a comparable 30-day mortality rate after LDLT (3.9% in both) and similar hospital stays (36 days vs. 40 days). The 1-, 3-, and 5-year graft survival rates in the elderly group were 92.0%, which was comparable to those in the younger group (p = 0.517), as confirmed by PSM. Notably, all donors for elderly patients were the children of the recipients, with an average age of 41.6 years, and grafts from donors aged ≥50 years were not utilized, signifying the use of high-quality grafts. Our inclusion criterion for elderly recipients was strictly defined as an ECOG-PS score of 0-2, which played a pivotal role in achieving favorable postoperative outcomes. LDLT can be performed safely for elderly patients aged 70 years or older, provided they have a preserved PS and receive high-quality grafts from younger donors, inevitably all children of elderly recipients. This approach yields acceptable long-term outcomes. Consequently, age alone should not serve as an absolute contraindication for LDLT.

Successful Liver Retransplantation in a Patient With Disseminated Aspergillosis and Nocardiosis: A Case Report

Clinical guidelines list active fungal infection and sepsis as contraindications to liver transplantation due to the risk of worsening infection with immunosuppression postoperatively. Mortality from systemic opportunistic infections in transplant recipients is high, approaching 100% for disseminated aspergillosis. However, the optimal duration of treatment required before transplant is unclear. Additionally, delaying surgery while the infection is treated risks death from hepatic decompensation and physical deconditioning, preventing progression to transplantation. Here, we present a patient who underwent successful repeat liver transplantation for recurrent autoimmune hepatitis and graft rejection while undergoing treatment for disseminated aspergillosis and nocardiosis. He had pulmonary, hepatic, and central nervous system involvement. He had received 2 months of antimicrobials but had ongoing radiologic evidence of infection when listed for retransplantation. He remains well and infection-free 1 year postoperatively. Few cases of successful liver transplantation in the setting of disseminated aspergillosis have been reported previously. To our knowledge, this is the first successful liver transplant in a patient with disseminated nocardial infection.

Descriptive study on risk of increased morbidity of schistosomiasis and graft loss after liver transplantation.

Solid-organ transplantation procedures have witnessed a surge in frequency. Consequently, increased attention to associated infections and their impact on graft success is warranted. The liver is the principal target for infection by the flatworm Schistosoma mansoni. Hence, rigorous screening protocols for this parasite should be implemented for liver transplantation donors and recipients. This study investigated the risks posed by schistosomiasis-infected liver tissues for successful liver transplantation (LT), considering donors and recipients, by analyzing reported cases. Among the 43 patients undergoing LT (donors = 19; recipients = 24), 32 were infected with S. mansoni, five were infected with other Schistosoma species, and no identification was made in four patients. Reported follow-up periods ranged from 1 to 132 months, and all patients achieved successful recovery. As these helminths do not replicate in their vertebrate hosts, immunosuppressive treatment is not expected to promote increased morbidity or reactivation. Moreover, suspected or confirmed schistosomiasis infections often have a benign course, and generally, should not prevent LT. The available literature was reviewed and a provisional screening protocol has been proposed.

Clinical course of COVID-19 infection in liver transplant patients

In the presence of chronic liver diseases, the post‑infectious period of COVID‑19 is difficult and potentially mortal. The impact of COVID‑19 on liver transplant patients has not been thoroughly investigated.&#x0D; Objective — to study the characteristics of the clinical course of COVID‑19 in liver transplant patients.&#x0D; Materials and methods. At the end of December 2014, the first successful liver transplant operation in Georgia was performed at the Batumi Referral Hospital of the Autonomous Republic of Adjara. To date, a total of surgical interventions have been conducted, including 42 surgeries since the beginning of the pandemic. We analysed&#x0D; The incidence of COVID‑19 infection in the cohort of 88 patients throughout their hospital stay after liver transplant and at the late postoperative period was analysed, as well as the characteristics of the clinical course of COVID‑19. To prevent COVID‑19 transmission within the hospital, a special protocol been developed: to ensure that the patient is safely isolated from contact with the source of infection. In the postoperative period, all patients received immunosuppressive therapy. To monitor the course of the disease, an interdisciplinary team was created, which consisted of a transplant surgeon, hepatologist, gastroenterologist, infectious disease specialist, therapist, and immunologist. The consultation was held at the place of residence and treatment of a patient.&#x0D; Results. No cases of COVID‑19 infection were reported among patients at the hospital where the liver transplant was conducted. In the late period, COVID‑19 was registered in 17 (19.3%) patients, of whom one (5.9%) died from the infection. One patient was infected with COVID‑19 twice. We have identified four variants of the clinical course of COVID‑19: mild (23.5%) — without any symptoms except for mild respiratory symptoms; aggravated (41.2%) — mild respiratory symptoms and dyspeptic symptoms without significant changes in clinical diagnostic parameters; moderate (29.4%) — cough without sputum, hyperthermia for three days, decreased sense of smell, the presence of dyspeptic symptoms, increased average values of biochemical parameters (alanine aminotransferase, aspartate aminotransferase, γ‑glutamyl transpeptidase, alkaline phosphatase, total bilirubin); severe (5.9%) — development of multiple organ failure.&#x0D; Conclusions. The implemented set of preventive measures ensured the patient’s protection from COVID‑19 infection in all cases during their hospital stay. In liver transplant patients.&#x0D;

Lipid disorders before and after successful liver transplantation.

Liver transplantation (LTx) is the only successful treatment for end-stage liver disease. The results of liver transplantation depend not only on graft survival but may be also affected by superimposed cardiovascular morbidities. The aim of this retrospective study was to assess the prevalence of lipid disorders as one of the important cardiovascular risk factors in patients before and after successful LTx. One hundred eleven patients who underwent liver transplantation because of liver cirrhosis and survived at least 2 years with functioning graft between November 2005 and May 2014 were included in this retrospective analysis. The mean age of the patients at the time of liver transplantation was 49.7±12.2 years. The prevalence of dyslipidemia was assessed before and two years after liver transplantation. This was analyzed in relation to the etiology of liver disease, including alcohol toxicity, viral or autoimmune diseases. The prevalence of hypertriglyceridemia before and after LTx was 13.5% and 40.5%, respectively (P<0.001). Similarly, hypercholesterolemia was noted in 17.1% and 51.4% respectively (P<0.001). The annual incidence of hypertriglyceridemia and hypercholesterolemia during the first two years after LTx was 16.2% and 20.7%, respectively. The prevalence of hypertriglyceridemia (18.5% vs 66.7%, P<0.001) and hypercholesterolemia (29.6% vs 70.0%, P=0.002) was significantly lower in patients with the autoimmune cause of liver cirrhosis in comparison to patients with the alcoholic liver disease. The prevalence of dyslipidemia is increased after liver transplantation. The prevalence of dyslipidemia may be related to the cause of liver injury before LTx.

Feasibility and outcomes of living-donor liver transplantation utilizing the right hemi-liver graft with portal vein anatomical variations

PurposePortal vein (PV) reconstruction is a key factor for successful living-donor liver transplantation (LDLT). Anatomical variations of right PV (RPV) are encountered among potential donors.MethodsTo evaluate a single center experience of reconstruction techniques for the right hemi-liver grafts with PV variations during the period between May 2004 and 2022.ResultsA total of 915 recipients underwent LDLT, among them 52 (5.8%) had RPV anatomical variations. Type II PV was found in 7 cases (13.5%), which were reconstructed by direct venoplasty. Type III PV was found in 27 cases (51.9%). They were reconstructed by direct venoplasty in 2 cases (3.8%), Y graft interposition in 2 cases (3.8%), and in situ double PV anastomoses in 23 cases (44.2%). Type IV PV was found in 18 cases (34.6%) and was reconstructed by Y graft interposition in 9 cases (17.3%), and in situ double PV anastomoses in 9 cases (17.3%).Early right posterior PV stenosis occurred in 2 recipients (3.8%). Early PV thrombosis occurred in 3 recipients (5.8%). The median follow-up duration was 54.5 months (4 – 185). The 1-, 3-, and 5-years survival rates were 91.9%, 86%, and 81.2%, respectively. Late PV stenosis occurred in 2 recipients (3.8%) and was managed conservatively.ConclusionUtilization of potential living donors with RPV anatomic variations may help to expand the donor pool. We found that direct venoplasty and in situ dual PV anastomoses techniques were safe, feasible, and associated with successful outcomes.

P5.3: Successful liver transplantation using a deceased donor liver with glycogenic hepatopathy pathologic appearance.

P5.3: Successful liver transplantation using a deceased donor liver with glycogenic hepatopathy pathologic appearance.

Successful Orthotopic Liver Transplantation in Mice Utilizing Microcomputed Tomography Angiography.

Microcomputed tomography (microCT) angiography is an invaluable resource to researchers. New advances in this technology have allowed for high-quality images to be obtained of micro-vasculature and are high-fidelity tools in the field of organ transplantation. In this model of orthotopic liver transplantation (OLT) in mice, microCT affords the opportunity to evaluate allograft anastomosis in real time and has the added benefit of not having to sacrifice study animals. The choice of contrast, as well as image acquisition settings, create a high-definition image, which gives researchers invaluable information. This allows for evaluation of the technical aspects of the procedure as well as potentially evaluating different therapeutics over an extended duration of time. In this protocol, we detail an OLT model in mice in a stepwise fashion and finally describe a microCT protocol that can give high-quality images, which aid researchers in in-depth analysis of solid organ transplantation. We provide a step-by-step guide for liver transplantation in a mouse, as well as briefly discuss a protocol for evaluating the patency of the graft through microCT angiography.

Successful liver transplantation from a donor with occlusive portal vein thrombosis

Introduction. The shortage of donor organs has been and remains the basic problem of clinical transplantation and the expansion of the organ pool by using marginal donor organs has become one of its solutions. In this regard, every decision to use a "non-standard" or "non ideal" organ for transplantation should be made carefully.Aim. Demonstration of successful liver transplantation from a donor with brain death and occlusive thrombosis of the splanchnic venous system.Description. A 34-year-old donor without serious concomitant pathology was diagnosed with total portal thrombosis during liver procurement. After cold aortic perfusion, a thrombectomy from the portal vein was performed. At the “backtable” stage, an additional perfusion was made through the portal vein, the results of which confirmed the patency of the portal system. The liver graft was transplanted to a 33-year-old recipient; the postoperative period was uneventful, the patient was discharged on the 17-th postoperative day.Conclusions. Portal vein thrombosis in a donor liver is rare. A positive decision on liver transplantation from a donor with portal vein thrombosis should be based on the confirmed patency of the portal system. It is desirable that these data be supplemented by a histological examination of the donor liver. The donor organs shortage needs to expand the criteria for post-mortem organ donation. However, every decision should be made in the light of individual characteristics of the donor-recipient pair.

Successful Liver Transplantation From a Deceased Donor With Congenital Extrahepatic Portosystemic Shunt: A Case Report

Congenital extrahepatic portosystemic shunt belongs to a family of rare vascular abnormalities. We present a case of congenital extrahepatic portosystemic shunt occurring in a 42-year-old man who died of cerebral hemorrhage and donated his liver. His portal vein angiography revealed that the main portal vein communicated with the left renal vein, suggesting a portosystemic shunt. A liver biopsy showed that the liver tissue structure was normal. His liver was not involved, and the transplantation was carried out smoothly. The recipient recovered smoothly, and the function of the transplanted liver was good.

Successful liver transplantation from deceased donors with active COVID-19 infections with undetectable SARS-CoV-2 in donor liver and aorta.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had unprecedented effects on society and modern healthcare. In liver transplantation, uncertainty regarding the safety of performing transplants during the early stage of the pandemic resulted in increased waitlist mortality. Additionally, concerns about disease transmission led to avoidance of deceased donors with COVID-19 infections. Several successful case reports describing incidental transplant of organs from donors with COVID-19 infections or intentional transplant of such donors into recipients with current or prior COVID-19 infections prompted the transplant community to re-evaluate that position. While excellent short-term results have been published, little is known about use of donors with active infections and the extent of COVID-19 organ involvement, which may affect long term outcomes. We report the successful transplantation of three livers from deceased donors with active COVID-19 infections. Donor liver and aortic tissues were evaluated by sensitive molecular testing for SARS-CoV-2 RNA via in situ hybridization and real-time quantitative reverse transcription PCR. Postoperatively, all patients had excellent allograft function, without clinical or molecular evidence of SARS-CoV-2 transmission in donor tissues. This evidence supports the use of liver donors with active COVID-19 infections.

Patients’ perceptions of the definition of a textbook outcome following liver transplantation

BackgroundA textbook outcome (TO) describes the results of a successful liver transplantation (LT) in which all aspects of the LT and posttransplant courses were uneventful. We compared patient perceived experience of a TO with clinically defined TO. MethodsThis was a single-institution cohort study with retrospective chart review including patients who underwent LT from 2019 to 2021. Patients were asked to complete the survey at a scheduled posttransplant visit. The survey was designed to assess their viewpoints on the definition of a TO. A clinically defined TO was defined as no mortality, no severe complications, no need for reintervention, no prolonged hospital and intensive care unit stays, and no readmission. ResultsOf the 182 patients who were contacted, 132 (72.5%) completed the survey. Overall, 98 patients (74%) considered that they had experienced a TO. The clinically defined TO rate was 22.0%. Multivariate analysis showed that patients who did not experience severe complications were more likely to consider that they had a TO (P = 0.01; odds ratio: 3.2; 95% confidence interval: 1.3–7.9). ConclusionsFrom patients’ perspectives, survival and avoidance of complications were the major characteristics of a TO.

Effect of Melatonin on Increasing the Effectiveness of Liver Preservation Solution.

Various tissue preservation solutions are used during the removal of the organ and during transplantation to protect the normal histological and biochemical characteristics of tissue while performing a successful liver transplant. In our study, it was aimed to investigate the effects of intraperitoneal melatonin administration on liver preservation damage before transplantation. In our study, the histological and biochemical characteristics of University of Wisconsin+melatonin group rats treated with melatonin 45 minutes before hepatectomy were compared between serum physiologic group and University of Wisconsin group. When hematoxylin and eosin staining was evaluated in terms of hydropic degeneration, sinusoidal dilatation, and hepatocyte necrosis, there was no statistically significant difference. Caspase 3 immunohistochemical staining showed a significant increase in Caspase 3 immunoreactivity positivity at the 12th-hour University of Wisconsin group compared to University of Wisconsin+melatonin group. As a result of biochemical analysis, the malondialdehyde and total oxidant status levels in the University of Wisconsin+melatonin group decreased significantly compared to the University of Wisconsin group. When the reduced glutathione activity and total antioxidant capacity level were compared, a significant increase was observed in the University of Wisconsin+melatonin group compared to the University of Wisconsin group at the 12th hour. It was also found that aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels decreased significantly in the University of Wisconsin+melatonin 12th-hour group compared to the University of Wisconsin 12th hour and control group. When the findings were evaluated, intraperitoneal administration of melatonin, a cytoprotective antioxidant, was found to play an effective role in preserving immunohistochemical and biochemical properties of liver tissue integrity and hepatocytes in University of Wisconsin solution.

Successful liver transplantation from a deceased donor who was on hemodialysis for 10 years

Objective: to analyze the possibility of using the liver of a donor undergoing hemodialysis as a transplant.Materials and methods. A case of successful liver transplantation (LT) from a 40-year-old deceased donor, who had been on hemodialysis for 10 years for chronic pyelonephritis and nephrosclerosis, is presented. Of the known hemodialysis complications of chronic kidney disease, the donor’s medical records showed anemia and grade 3 arterial hypertension.Results. The recipient’s post-LT period had no significant differences from the postoperative period of those that received liver from donors with standard criteria.Conclusion. Our first experience with the use of a liver transplant from a donor who was on hemodialysis, in the absence of other risk factors, suggests that the liver of this category of donors can be used for transplantation.

The evolution of the liver transplant candidate.

The first successful human liver transplant (LT) was done over 60 years ago; since the early pioneering days, this procedure has become a routine treatment with excellent outcomes for the great majority of recipients. Over the last six decades, indications have evolved. Use of LT for hepatic malignancy is becoming less common as factors that define a successful outcome are being increasingly defined, and alternative therapeutic options become available. Both Hepatitis B and C virus associated liver disease are becoming less common indications as medical treatments become more effective in preventing end-stage disease. Currently, the most common indications are alcohol-related liver disease and metabolic associated liver disease. The developing (and controversial) indications include acute on chronic liver failure, alcoholic hepatitis and some rarer malignancies such as non-resectable colorectal cancer liver metastases, neuroendocrine tumours and cholangiocarcinoma. Candidates are becoming older and with greater comorbidities, A relative shortage of donor organs remains the greatest cause for reducing access to LT; therefore, various countries have developed transparent approaches to allocation of this life saving and life enhancing resource. Reliance on prognostic models has gone some way to improve transparency and increase equity of access but these approaches have their limitations.

Gut Microbiota and Liver Transplantation: Immune Mechanisms behind the Rejection.

Liver transplantation (LT) is the treatment of choice for patients with cirrhosis, decompensated disease, acute liver failure, and hepatocellular carcinoma (HCC). In 3-25% of cases, an alarming problem is acute and chronic cellular rejection after LT, and this event can lead to the need for new transplantation or the death of the patient. On the other hand, gut microbiota is involved in several mechanisms sustaining the model of the "gut-liver axis". These include modulation of the immune response, which is altered in case of gut dysbiosis, possibly resulting in acute graft rejection. Some studies have evaluated the composition of the gut microbiota in cirrhotic patients before and after LT, but few of them have assessed its impact on liver rejection. This review underlines the changes in gut microbiota composition before and after liver transplantation, hypothesizing possible immune mechanisms linking dysbiosis to transplantation rejection. Evaluation of changes in the gut microbiota composition in these patients is therefore essential in order to monitor the success of LT and eventually adopt appropriate preventive measures.