Recent advances in understanding and managing liver transplantation

Usefulness of Diffusion-Weighted Imaging in Evaluating Acute Cellular Rejection and Monitoring Treatment Response in Liver Transplant Recipients

Acute cellular rejection (ACR) is a significant immune issue among recipients following liver transplantation. Although diffusion-weighted magnetic resonance imaging (DWI) is widely used for diagnosing liver disease, it has not yet been utilized for monitoring ACR in patients after liver transplantation. Therefore, the aim of this study was to evaluate the efficacy of DWI in monitoring treatment response among recipients with ACR. This study enrolled 25 recipients with highly suspected ACR rejection, and all subjects underwent both biochemistry and DWI scans before and after treatment. A pathological biopsy was performed 4 to 24 h after the first MRI examination to confirm ACR and degree of rejection. All patients were followed up and underwent a repeated MRI scan when their liver function returned to the normal range. After data acquisition, the DWI data were post-processed to obtain the apparent diffusion coefficient (ADC) map on a voxel-by-voxel basis. Five regions of interest were identified on the liver parenchyma to measure the mean ADC values from each patient. Finally, the mean ADC values and biochemical markers were statistically compared between ACR and non-ACR groups. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of the ADC and biochemical data in detecting ACR, and correlation analysis was used to understand the relationship between the ADC values, biochemical markers, and the degree of rejection. The histopathologic results revealed that 20 recipients had ACR, including 10 mild, 9 moderate, and 1 severe rejection. The results demonstrated that the ACR patients had significantly lower hepatic ADC values than those in patients without ACR. After treatment, the hepatic ADC values in ACR patients significantly increased to levels similar to those in non-ACR patients with treatment. The ROC analysis showed that the sensitivity and specificity for detecting ACR were 80% and 95%, respectively. Furthermore, the correlation analysis revealed that the mean ADC value and alanine aminotransferase level had strong and moderate negative correlation with the degree of rejection, respectively (r = -0.72 and -0.47). The ADC values were useful for detecting hepatic ACR and monitoring treatment response after immunosuppressive therapy.

Overcoming the hurdles of steatotic grafts in liver transplantation: Insights into survival and prognostic factors

With increasing metabolic dysfunction-associated steatotic liver disease, the use of steatotic grafts in liver transplantation (LT) and their impact on postoperative graft survival (GS) needs further exploration. Analyzing adult LT recipient data (2002-2022) from the United Network for Organ Sharing database, outcomes of LT using steatotic (≥30% macrosteatosis) and nonsteatotic donor livers, donors after circulatory death, and standard-risk older donors (age 45-50) were compared. GS predictors were evaluated using Kaplan-Meier and Cox regression analyses. Of the 35,345 LT donors, 8.9% (3,155) were fatty livers. The initial 30-day postoperative period revealed significant challenges with fatty livers, demonstrating inferior GS. However, the GS discrepancy between fatty and nonfatty livers subsided over time ( p = 0.10 at 5 y). Long-term GS outcomes showed comparable or even superior results in fatty livers relative to nonsteatotic livers, conditional on surviving the initial 90 postoperative days ( p = 0.90 at 1 y) or 1 year ( p = 0.03 at 5 y). In the multivariable Cox regression analysis, the high body surface area (BSA) ratio (≥1.1) (HR 1.42, p = 0.02), calculated as donor BSA divided by recipient BSA, long cold ischemic time (≥6.5 h) (HR 1.72, p < 0.01), and recipient medical condition (intensive care unit hospitalization) (HR 2.53, p < 0.01) emerged as significant adverse prognostic factors. Young (<40 y) fatty donors showed a high BSA ratio, diabetes, and intensive care unit hospitalization as significant indicators of a worse prognosis ( p < 0.01). Our study emphasizes the initial postoperative 30-day survival challenge in LT using fatty livers. However, with careful donor-recipient matching, for example, avoiding the use of steatotic donors with long cold ischemic time and high BSA ratios for recipients in the intensive care unit, it is possible to enhance immediate GS, and in a longer time, outcomes comparable to those using nonfatty livers, donors after circulatory death livers, or standard-risk older donors can be anticipated. These novel insights into decision-making criteria for steatotic liver use provide invaluable guidance for clinicians.

Has the risk of liver re-transplantation improved over the two decades?

BACKGROUND

Despite advancements in liver transplantation (LT) over the past two decades, liver re-transplantation (re-LT) presents challenges. This study aimed to assess improvements in re-LT outcomes and contributing factors.

METHODS

Data from the United Network for Organ Sharing database (2002-2021) were analyzed, with recipients categorized into four-year intervals. Trends in re-LT characteristics and postoperative outcomes were evaluated.

RESULTS

Of 128,462 LT patients, 7254 received re-LT. Graft survival (GS) for re-LT improved (91.3%, 82.1%, and 70.8% at 30 days, 1 year, and 3 years post-LT from 2018 to 2021). However, hazard ratios (HRs) for GS remained elevated compared to marginal donors including donors after circulatory death (DCD), although the difference in HRs decreased in long-term GS. Changes in re-LT causes included a reduction in hepatitis C recurrence and an increase in graft failure post-primary LT involving DCD. Trends identified included recent decreased cold ischemic time (CIT) and increased distance from donor hospital in re-LT group. Meanwhile, DCD cohort exhibited less significant increase in distance and more marked decrease in CIT. The shortest CIT was recorded in urgent re-LT group. The highest Model for End-Stage Liver Disease score was observed in urgent re-LT group, while the lowest was recorded in DCD group. Analysis revealed shorter time interval between previous LT and re-listing, leading to worse outcomes, and varying primary graft failure causes influencing overall survival post-re-LT.

DISCUSSION

While short-term re-LT outcomes improved, challenges persist compared to DCD. Further enhancements are required, with ongoing research focusing on optimizing risk stratification models and allocation systems for better LT outcomes.

Integrative analyses of genes related to liver ischemia reperfusion injury

Background

Liver ischemia reperfusion injury (LIRI) is not only a common injury during liver transplantation and major hepatic surgery, but also one of the primary factors that affect the outcome of postoperative diseases. However, there are still no reliable ways to tackle the problem. Our study aimed to find some characteristic genes associated with immune infiltration that affect LIRI, which can provide some insights for future research in the future. Therefore, it is essential for the treatment of LIRI, the elucidation of the mechanisms of LIRI, and exploring the potential biomarkers. Efficient microarray and bioinformatics analyses can promote the understanding of the molecular mechanisms of disease occurrence and development.

Method

Data from GSE151648 were downloaded from GEO data sets, and we performed a comprehensive analysis of the differential expression, biological functions and interactions of LIRI-associated genes. Then we performed Gene ontology (GO) analysis and Kyotoencydlopedia of genes and genomes (KEGG) enrichment analysis of DEGs. At last, we performed a protein-protein interaction network to screen out hub genes.

Results

A total of 161 differentially expressed genes (DEGs) were identified. GO analysis results revealed that the changes in the modules were mostly enriched in the neutrophil degranulation, neutrophil activation involved in immune response, and neutrophil mediated immunity. KEGG enrichment analysis of DEGs demonstrated that LIRI mainly involved the cytokine-cytokine receptor interaction. Our data indicated that macrophages and neutrophils are closely related to LIRI. 9 hub genes were screened out in the protein-protein interaction network.

Conclusions

In summary, our data indicated that neutrophil degranulation, neutrophil activation involved in immune response, neutrophil mediated immunity and cytokine-cytokine receptor interaction may play a key role in LIRI, HRH1, LRP2, P2RY6, PKD1L1, SLC8A3 and TNFRSF8, which were identified as potential biomarkers in the occurrence and development of LIRI. However, further studies are needed to validate these findings and explore the molecular mechanism of these biomarkers in LIRI.

Initiation of Liver Transplant in Nepal: A Milestone

Background

The incidence of chronic liver disease is increasing in the Nepalese population. Liver transplantation (LT) is the best option for patients with end-stage liver disease (ESLD). Nepal's first liver transplant was performed in 2016 in an international collaborative effort at Shahid Dharmabhakta National Transplant Centre (SDNTC), Bhaktapur, Nepal. We aim to report details of the first five patients who had undergone liver transplantation in SDNTC before the beginning of the COVID-19 outbreak in the history of transplantation in Nepal.

Method

A descriptive analysis of the clinical data of five adult recipients of liver transplantation at SDNTC was done. We described the patient's demographics, length of stay, and survival of all the first five patients who had undergone four living donor liver transplantations and one brain-dead donor liver transplantation in SDNTC before the beginning of the COVID-19 outbreak.

Results

Recipients were between 36 and 63 years old. The recipients of the four live donor liver transplants (LDLT) and one brain-dead donor liver transplant (DDLT) had alcoholic liver disease and cryptogenic liver disease, leading to end-stage liver disease. The model for end-stage liver disease (MELD) scores ranged from 23 to 34. Out of five, four recipients and four donors are doing well and relishing the prospect of a normal life, while the recipient of a brain-dead donor liver transplant passed away due to postoperative primary graft failure.

Conclusion

Despite the small number of liver transplants that have been done, the success of these has created confidence in a sustainable liver transplantation program in Nepal.

Anastomotic biliary stricture following liver transplantation and management analysis: 15 years of experience at a high-volume transplant center

INTRODUCTION

The occurrence of anastomotic biliary stricture (BS) remains an essential issue following liver transplantation (LT). The present study aimed to compare our findings regarding the incidence of anastomotic BS to what is known.

METHODS

The present study is a single-center, retrospective cohort study of a total number of 717 consecutive patients (426 men and 291 women) who had undergone LT from January 2001 to March 2016. Multivariable Cox regression analysis was conducted to evaluate the risk factors associated with anastomotic BS development.

RESULTS

Post-transplant anastomotic BS developed in 70 patients (9.8%). In the Cox multivariate analysis (a stepwise forward conditional method), factors including biliary leak (hazard ratio [HR]: 6.61, 95% confidence interval [CI]: 3.08-17.58, p < 0.001), hepatic artery thrombosis (HR: 2.29, 95% CI: 1.03-5.88; p = 0.003), and acute rejection (HR: 2.18, 95% CI: 1.16-3.37; p = 0.006) were identified as independent risk factors for the development of anastomotic BS. Surgery in 6 cases (66.7%), followed by endoscopic retrograde cholangiopancreatography (ECRP) with a metal stent in 18 cases (62.1%), percutaneous transhepatic biliary drainage in 9 (20.9%), and ERCP with a single plastic stent in 8 (18.2%), had the highest effectiveness rates in the management of BS, respectively.

CONCLUSIONS

Risk factors including biliary leak, hepatic artery thrombosis, and acute rejection were independently associated with an anastomotic BS. ERCP with a metal stent may be considered as an effective treatment procedure with a relatively low complication rate in the management of benign post-LT anastomotic BS.

Use of blood oxygen level-dependent magnetic resonance imaging to detect acute cellular rejection post-liver transplantation

OBJECTIVES

Acute cellular rejection (ACR) is a major immune occurrence post-liver transplant that can cause abnormal liver function. Blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) can be used to evaluate liver disease, but it has not been utilized in the diagnosis of ACR post-liver transplant. Therefore, the purpose of this study is to evaluate the diagnostic performance of BOLD MRI and to monitor treatment response in recipients with ACR.

METHODS

This prospective study was approved by the local institutional review board. Fifty-five recipients with highly suspected ACR were enrolled in this study. Each patient underwent hepatic BOLD MRI, blood biochemistry, and biopsy before treatment. Of 55 patients, 19 recipients with ACR received a follow-up MRI after treatment. After obtaining the R2* maps, five regions-of-interest were placed on liver parenchyma to estimate the mean R2* values for statistical analysis. Receiver operating characteristic curve (ROC) analysis was performed to assess the diagnostic performance of R2* values in detecting patients with ACR.

RESULTS

The histopathologic results showed that 27 recipients had ACR (14 mild, 11 moderate, and 2 severe) and their hepatic R2* values were significantly lower than those of patients without ACR. ROC analysis revealed that the sensitivity and specificity of the R2* values for detection of ACR were 82.1% and 89.9%, respectively. Moreover, the R2* values and liver function in patients with ACR significantly increased after immunosuppressive treatment.

CONCLUSION

The non-invasive BOLD MRI technique may be useful for assessment of hepatic ACR and monitoring of treatment response after immunosuppressive therapy.

KEY POINTS

• Patients with acute cellular rejection post-liver transplant exhibited significantly decreased R2* values in liver parenchyma. • R2* values and liver function were significantly increased after immunosuppressive therapy. • R2* values were constructive indicators in detecting acute cellular rejection due to their high sensitivity and specificity.

Obstetrical and gynecologic challenges in the liver transplant patient

An increasing number of childbearing agewomen undergo liver transplantation (LT) in the United States. Transplantation in this patient subgroup poses a significant challenge regarding the plans for future fertility, particularly in terms of immunosuppression and optimal timing of conception. Intrapartum LT is only rarely performed as the outcome is commonly dismal for the mother or more commonly the fetus. On the other hand, the outcomes of pregnancy in LT recipients are favorable, and children born to LT recipients are relatively healthy. Counseling on pregnancy should start before LT and continue after LT up until pregnancy, while all pregnant LT recipients must be managed by amultidisciplinary team, including both an obstetrician and a transplant hepatologist. Additionally, an interval of at least 1-2 years after successful LT is recommended before considering pregnancy. Pregnancy-induced hypertension, pre-eclampsia, and gestational diabetes mellitus are reported more commonly during the pregnancies of LT recipients than in the pregnancies of non-transplant patients. As adverse fetal outcomes, such asmiscarriage, abortion, stillbirth, or ectopic pregnancy, may occur more often than in the non-transplant population, early planning or delivery either through a planned induction of labor or cesarean section is critical to minimize the risk of complications. No significant long-term physical or phycological abnormalities have been reported in children born to LT recipients.

Pulmonary Complications in Candidates for Liver Transplantation

The liver plays a pivotal role in maintaining the homeostasis of various organ systems. Also, end-stage liver disease and its complications are major causes of morbidity and mortality among adults. Individuals who develop a chronic liver disease are at increased risk of progression to multi-organ dysfunction, including the pulmonary system. The clinical complications of pulmonary problems related to the presence of liver disease range from mild (such as hypoxemia) to life-threatening diseases (such as portopulmonary hypertension and hepatopulmonary syndrome). Herein, the major pulmonary complications related to liver cirrhosis and considerations for performing liver transplantation are reviewed.

Survival Outcomes After Intracranial Hemorrhage in Liver Disease

BACKGROUND

Survival outcomes for patients with liver disease who suffer an intracranial hemorrhage (ICH) have not been thoroughly investigated.

OBJECTIVE

To understand survival outcomes for 3 groups: (1) patients with an admission diagnosis of liver disease (end-stage liver disease [ESLD] or non-ESLD) who developed an ICH in the hospital, (2) patients with ESLD who undergo either operative vs nonoperative management, and (3) patients with ESLD on the liver transplant waitlist who developed an ICH in the hospital.

METHODS

We retrospectively reviewed hospital charts from March 2006 through February 2017 of patients with liver disease and an ICH evaluated by the neurosurgery service at a single academic medical center. The primary outcome was survival.

RESULTS

We included a total of 53 patients in this study. The overall survival for patients with an admission diagnosis of liver disease who developed an ICH (n = 29, 55%) in the hospital was 22%. Of those patients with an admission diagnosis of liver disease, 27 patients also had ESLD. Kaplan-Meier analysis found no significant difference in survival for ESLD patients (n = 33, 62%) according to operative status. There were 11 ESLD patients on the liver transplant waitlist. The overall survival for patients with ESLD on the liver transplant waitlist who suffered an in-hospital ICH (n = 7, 13%) was 14%.

CONCLUSION

ICH in the setting of liver disease carries a grave prognosis. Also, a survival advantage for surgical hematoma evacuation in ESLD patients is not clear.

Knowledge and Attitudes on Organ Donation From the Perspective of Liver Transplant Patients

PURPOSE

This study was performed to investigate the knowledge and attitudes about organ donation from the perspective of liver transplant patients.

DESIGN AND METHODS

The study was conducted at the organ transplantation clinics. The data were collected by the researchers from 129 participants using in-person interviews.

FINDINGS

In this study, 83% of patients received the organ from live donors, 36% received liver transplants in the previous 1 year, more than 70% agreed to donate their organs, and 80% thought awareness should be raised in society about organ donation.

CONCLUSION

It was found that the participants in the sample needed information on the issue, although the sample consisted of individuals who had experienced organ donation. It is important that nurses and nurse managers understand the level of knowledge and the attitudes of organ donation patients who have undergone liver transplantation. Worldwide, organ donation is not at the desired level. This study aims to enhance in nurses and nurse managers the foresight regarding and awareness about behaviors of transplantation patients.

Effect of Hepatic Macrophage Polarization and Apoptosis on Liver Ischemia and Reperfusion Injury During Liver Transplantation

Ischemia-reperfusion (I/R) injury is injury caused by a limited blood supply and subsequent blood supply recovery during liver transplantation. Serious ischemia-reperfusion injury is the main cause of transplant failure. Hepatic I/R is characterized by tissue hypoxia due to a limited blood supply and reperfusion inducing oxidative stress and an immune response. Studies have confirmed that Kupffer cells (KCs), resident macrophages in the liver, play a key role in aseptic inflammation induced by I/R. In liver macrophage polarization, M1 macrophages activated by interferon-γ (IFN-γ) and lipopolysaccharide (LPS) exert a pro-inflammatory effect and release a variety of inflammatory cytokines. M2 macrophages activated by IL-4 have an anti-inflammatory response. M1-type KCs are the dominant players in I/R as they secrete various pro-inflammatory cytokines that exacerbate the injury and recruit other types of immune cells via the circulation. In contrast, M2-type KCs can ameliorate I/R through unregulated anti-inflammatory factors. A new notion has been proposed that KC apoptosis may influence I/R in yet another manner as well. Management of KCs is expected to help improve I/R. This review summarizes the effects of hepatic macrophage polarization and apoptosis on liver I/R.

EVALUATION AND SELECTION OF CANDIDATES FOR LIVER TRANSPLANTATION: AN ECONOMIC PERSPECTIVE

BACKGROUND

Over the next 20 years, the number of patients on the waiting list for liver transplantation (LTx) is expected to increase by 23%, while pre-LTx costs should raise by 83%.

OBJECTIVE

To evaluate direct medical costs of the pre-LTx period from the perspective of a tertiary care center.

METHODS

The study included 104 adult patients wait-listed for deceased donor LTx between October 2012 and May 2016 whose treatment was fully provided at the study transplant center. Clinical and economic data were obtained from electronic medical records and from a hospital management software. Outcomes of interest and costs of patients on the waiting list were compared through the Kruskal-Wallis test. A generalized linear model with logit link function was used for multivariate analysis. P-values <0.05 were considered statistically significant.

RESULTS

The costs of patients who underwent LTx ($8,879.83; 95% CI 6,735.24-11,707.27; P<0.001) or who died while waiting ($6,464.73; 95% CI 3,845.75-10,867.28; P=0.04) were higher than those of patients who were excluded from the list for any reason except death ($4,647.78; 95% CI 2,469.35-8,748.04; P=0.254) or those who remained on the waiting list at the end of follow-up.

CONCLUSION

Although protocols of inclusion on the waiting list vary among transplant centers, similar approaches exist and common problems should be addressed. The results of this study may help centers with similar socioeconomic realities adjust their transplant policies.

Intraoperative liver steatosis characterization using diffuse reflectance spectroscopy

BACKGROUND

Liver steatosis is associated with poor outcome after liver transplantation and liver resection. There is a need for an accurate and reliable intraoperative tool to identify and quantify steatosis. This study aimed to investigate whether surface diffuse reflectance spectroscopy (DRS) measurements could detect liver steatosis on humans during liver surgery.

METHODS

The DRS instrumentation setup consists of a computer, a high-power tungsten halogen light source and two spectrometers, connected through a trifurcated optical fiber to a hand-held probe. Patients scheduled for open resection for liver tumors were considered for inclusion. Multiple DRS measurements were performed on the liver surface after mobilization.

RESULTS

In total, 1210 DRS spectra originated from 38 patients, were analyzed. When applying the data to an analytical model the volumetric absorption ratio factor of fat and water specified an explicit distinction between mild to moderate, and moderate to severe steatosis (p < 0.001). There were significant differences between none-to-mild and moderate-to-severe steatosis grade for the following parameters: reduced scattering coefficient (p < 0.001), Mie to total scattering fraction (p < 0.001), Mie slope (p = 0.003), lipid/(lipid + water) (p < 0.001), blood volume (p = 0.044) and bile volume (p < 0.001).

CONCLUSION

This study shows that it is possible to evaluate steatosis grades with hepatic surface diffuse reflectance spectroscopy measurements.

Orthotopic Liver Transplantation: Preliminary Analysis of Complications With Grafts From Elderly Donors

OBJECTIVE

This study aims to determine if donor grafts of patients older than 65 years develop more post-transplantation complications than those of younger patients.

DESIGN

This is a retrospective, observational study of liver transplant recipients during 12 months in Virgen del Rocio University Hospital. We compare incidence rates of reperfusion syndrome, acute kidney injury, and need for intra- and postoperative red blood cell transfusions in two donor age groups in which group A is <65 years old and group B is ≥65 years old.

RESULTS

Sixty cases were included. Reperfusion syndrome, acute kidney injury, and both intra- and postoperative red blood cell transfusion were more frequent in group A than group B (11.4% vs. 4%, P = .390; 44% vs. 32%, P = .423; 68.8% vs. 48%, P = .120; and 70.6% vs. 64%, P = .779, respectively). Six recipients (17.1%) died at 12 months from group A whereas there were no deaths register in group B during that time (P = .036).

CONCLUSION

Our results showed that including elderly donors does not aggravate incidence of complications, emphasizing that advanced age should not be an exclusion criteria for liver transplantation.

The long-term outcomes of cirrhotic patients with pleural effusion

BACKGROUND/AIM

A pleural effusion is an abnormal collection of fluid in the pleural space and may cause related morbidity or mortality in cirrhotic patients. Currently, there are insufficient data to support the long-term prognosis for cirrhotic patients with pleural effusion. In this study, we investigated the short- and long-term effects of pleural effusion on mortality in cirrhotic patients and evaluated the benefit of liver transplantation in these patients.

PATIENTS AND METHODS

The National Health Insurance Database, derived from the Taiwan National Health Insurance Program, was used to identify 3,487 cirrhotic patients with pleural effusion requiring drainage between January 1, 2007 and December 31, 2010. The proportional hazards Cox regression model was used to control for possible confounding factors.

RESULTS

The 30-day, 90-day, 1-year, and 3-year mortalities were 20.1%, 40.2%, 59.1%, and 75.9%, respectively, in the cirrhotic patients with pleural effusion. After Cox proportional hazard regression analysis adjusted by patient gender, age, complications of cirrhosis and comorbid disorders, old age, esophageal variceal bleeding, hepatocellular carcinoma, hepatic encephalopathy, pneumonia, renal function impairment, and without liver transplantation conferred higher risks for 3-year mortality in the cirrhotic patients with pleura effusion. Liver transplantation is the most important factor to determine the 3-year mortalities (HR: 0.17, 95% CI 0.11- 0.26, P < 0.001). The 30-day, 30 to 90-day, 90-day to 1-year, and 1 to 3-year mortalities were 5.7%, 13.4%, 20.4%, and 21.7% respectively, in the liver transplantation group, and 20.5%, 41.0%, 61.2%, and 77.5%, respectively, in the non-liver transplantation group.

CONCLUSION

In cirrhotic patients, the presence of pleural effusion predicts poor long-term outcomes. Liver transplantation could dramatically improve the survival and should be suggested as soon as possible.