Increased Posttransplant Mortality for Autoimmune Hepatitis Compared With Other Autoimmune Liver Diseases

Recurrence of autoimmune liver diseases after liver transplantation: Review and expert opinion statement

Autoimmune liver diseases (AILDs) constitute the fourth most common indication for liver transplantation (LT) across the world. In general, the outcomes after LT are acceptable; however, disease recurrence after LT is common for all AILD, which can negatively affect graft and overall survival. Several questions persist, including the risk factors associated with recurrent disease, optimal antirejection medications, strategies to reduce the risk of recurrence, and how to best incorporate these strategies into clinical practice. For that reason, we assembled an international group of experts to review evidence to address these outstanding questions regarding LT for AILD. Survival rates after LT are ~90% and 70% at 1 and 5 years, and recurrent disease occurs in 10%-50% of patients with AILD. In patients with disease recurrence, graft survival decreased by 18% and 28% and overall survival by 8% and 12% at 5 and 10 years after LT, respectively. Recurrent autoimmune hepatitis is associated with high aminotransferases and immunoglobulin G (IgG) before LT, lymphoplasmacytic infiltrates in the explants, and may be associated with the absence of steroids after LT. However, the efficiency and safety of triple immunosuppressive maintenance therapy is still debatable. Younger age at diagnosis with primary biliary cholangitis or LT is associated with primary biliary cholangitis recurrence. Preventive use of ursodeoxycholic acid reduces the risk of recurrence and has a benefit in graft and patient survival. Episodes of systemic inflammation, including T-cell-mediated rejection, active ulcerative colitis, and episodes of cholangitis, are associated with recurrent PSC. Recurrent disease for AILD is associated with worse graft and patient survival. Patients with autoimmune hepatitis could be considered for long-term low-dose predniso(lo)ne, whereas patients with primary biliary cholangitis should be placed on preventive ursodeoxycholic acid after LT. There are no specific treatments for PSC recurrence; however, adequate control of inflammatory bowel disease and optimal immunosuppression to avoid T-cell-mediated rejection should be encouraged.

Living-Donor Liver Transplant and Improved Post-Transplant Survival in Patients with Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is the leading indication of liver transplantation (LT) among autoimmune liver disease patients. There is a scarcity of studies comparing survival outcomes between living-donor liver transplants (LDLT)s and deceased-donor liver transplants (DDLTs) in this population. Using the United Network for Organ Sharing database, we compared 4679 DDLTs and 805 LDLTs. Our outcome of interest was post-LT patient survival and post-LT graft survival. A stepwise multivariate analysis was performed, adjusting for recipient age, gender, diabetes mellitus, ascites, hepatic encephalopathy, cholangiocarcinoma, hepatocellular carcinoma, race, and the model for end-stage liver disease (MELD) score; donor' age and sex were also included to the analysis. According to univariate and multivariate analysis, LDLT had a patient and graft survival benefit compared to DDLT (HR, 0.77, 95% CI 0.65-0.92; p < 0.002). LDLT patient survival (95.2%, 92.6%, 90.1%, and 81.9%) and graft survival (94.1%, 91.1%, 88.5%, and 80.5%) at 1, 3, 5, and 10 years were significantly better than DDLT patient survival (93.2%, 87.6%, 83.3%, and 72.7%) and graft survival (92.1%, 86.5%, 82.1%, and 70.9%) (p < 0.001) in the same interval. Variables including donor and recipient age, male recipient gender, MELD score, diabetes mellitus, hepatocellular carcinoma, and cholangiocarcinoma were associated with mortality and graft failure in PSC patients. Interestingly, Asians were more protected than Whites (HR, 0.61; 95% CI, 0.35-0.99; p < 0.047), and cholangiocarcinoma was associated with the highest hazard of mortality (HR, 2.07; 95% CI, 1.71-2.50; p < 0.001) in multivariate analysis. LDLT in PSC patients were associated with greater post-transplant patient and graft survival compared to DDLT patients.

Post-Transplant Immunosuppression in Autoimmune Liver Disease

Autoimmune liver diseases (AILDs) are a group of conditions where immune-mediated liver damage can lead to the need for transplantation. Collectively, they account for almost a quarter of all liver transplants. Outcomes in terms of graft and patient survival for all liver transplants have improved markedly over decades with improvements in patient selection, surgical techniques and longer-term care and this is also seen in patients with AILDs. The current five- and ten-year survival rates post-transplant in autoimmune disease are excellent, at 88% and 78%, respectively. A key factor in maintaining good outcomes post liver transplant for these autoimmune conditions is the immunosuppression strategy. These patients have increased the rates of rejection, and autoimmune conditions can all recur in the graft ranging from 12 to 60% depending on the population studied. Immunosuppressive regimens are centred on calcineurin inhibitors, often combined with low dose corticosteroids, with or without the addition of antimetabolite therapy. There is no clear evidence-based immunosuppressive regimen for these conditions, and a tailored approach balancing the individuals' immunological profile against the risks of immunosuppression is often used. There are disease-specific considerations to optimised graft function including the role of ursodeoxycholic acid in both primary biliary cholangitis and primary sclerosing cholangitis and the role and timing of colectomy in primary sclerosing cholangitis in inflammatory bowel disease patients. However, unmet needs still exist in the management of AILDs post liver transplantation particularly in building the evidence base for optimal immunosuppression as well as mitigating the risk of recurrent disease.

Examining the effect of synthetic data augmentation in polyp detection and segmentation

PURPOSE

As with several medical image analysis tasks based on deep learning, gastrointestinal image analysis is plagued with data scarcity, privacy concerns and an insufficient number of pathology samples. This study examines the generation and utility of synthetic samples of colonoscopy images with polyps for data augmentation.

METHODS

We modify and train a pix2pix model to generate synthetic colonoscopy samples with polyps to augment the original dataset. Subsequently, we create a variety of datasets by varying the quantity of synthetic samples and traditional augmentation samples, to train a U-Net network and Faster R-CNN model for segmentation and detection of polyps, respectively. We compare the performance of the models when trained with the resulting datasets in terms of F₁ score, intersection over union, precision and recall. Further, we compare the performances of the models with unseen polyp datasets to assess their generalization ability.

RESULTS

The average F₁ coefficient and intersection over union are improved with increasing number of synthetic samples in U-Net over all test datasets. The performance of the Faster R-CNN model is also improved in terms of polyp detection, while decreasing the false-negative rate. Further, the experimental results for polyp detection outperform similar studies in the literature on the ETIS-PolypLaribDB dataset.

CONCLUSION

By varying the quantity of synthetic and traditional augmentation, there is the potential to control the sensitivity of deep learning models in polyp segmentation and detection. Further, GAN-based augmentation is a viable option for improving the performance of models for polyp segmentation and detection.

Waitlist Mortality and Posttransplant Outcomes in African Americans with Autoimmune Liver Diseases

Background

Liver transplantation is indicated in end-stage liver disease due to autoimmune diseases. The liver allocation system can be affected by disparities such as decreased liver transplant referrals for racial minorities, especially African Americans that negatively impact the pre- and posttransplant outcomes.

Aim

To determine differences in waitlist survival and posttransplant graft survival rates between African American and Caucasian patients with autoimmune liver diseases. Study. The United Network for Organ Sharing database was used to identify all patients with autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis who underwent liver transplant from 1988 to 2019. We compared waitlist survival and posttransplant graft survival between Caucasians and African Americans using Kaplan–Meier curves and Cox regression models. We also evaluated the cumulative incidence of death or delisting for deterioration and posttransplant incidence of death and retransplantation using competing risk analysis.

Results

African Americans were more likely to be removed from the waitlist for death or clinical deterioration (subdistribution hazard ratio (SHR) 1.26, 95% CI 1–1.58, P=0.046) using competing risk analysis. On multivariate Cox regression analysis, there was no difference in posttransplant graft survival among the two groups (hazard ratio (HR) 1.10, 95% CI 0.98–1.23, P=0.081).

Conclusions

Despite the current efforts to reduce racial disparities, we found that African Americans are more likely to die on the waitlist for liver transplant and are less likely to be transplanted, with no differences in graft survival rates. The persistence of healthcare disparities continues to negatively impact African Americans.

Management of Autoimmune Liver Diseases after Liver Transplantation

Autoimmune liver diseases are characterized by immune-mediated inflammation and eventual destruction of the hepatocytes and the biliary epithelial cells. They can progress to irreversible liver damage requiring liver transplantation. The post-liver transplant goals of treatment include improving the recipient’s survival, preventing liver graft-failure, and decreasing the recurrence of the disease. The keystone in post-liver transplant management for autoimmune liver diseases relies on identifying which would be the most appropriate immunosuppressive maintenance therapy. The combination of a steroid and a calcineurin inhibitor is the current immunosuppressive regimen of choice for autoimmune hepatitis. A gradual withdrawal of glucocorticoids is also recommended. On the other hand, ursodeoxycholic acid should be initiated soon after liver transplant to prevent recurrence and improve graft and patient survival in primary biliary cholangitis recipients. Unlike the previously mentioned autoimmune diseases, there are not immunosuppressive or disease-modifying agents available for patients with primary sclerosing cholangitis. However, colectomy and annual colonoscopy are key components during the post-liver transplant period.

Longterm Survival After Liver Transplantation for Autoimmune Hepatitis: Results From the European Liver Transplant Registry

The aim of this study was to analyze longterm patient and graft survival after liver transplantation for autoimmune hepatitis (AIH-LT) from the prospective multicenter European Liver Transplant Registry. Patient and liver graft survival between 1998 and 2017 were analyzed. Patients after AIH-LT (n = 2515) were compared with patients receiving LT for primary biliary cholangitis (PBC-LT; n = 3733), primary sclerosing cholangitis (PSC-LT; n = 5155), and alcohol-related cirrhosis (AC-LT; n = 19,567). After AIH-LT, patient survival was 79.4%, 70.8%, and 60.3% and graft survival was 73.2%, 63.4%, and 50.9% after 5, 10, and 15 years of follow-up. Overall patient survival was similar to patients after AC-LT (P = 0.44), but worse than after PBC-LT (hazard ratio [HR], 1.48; P < 0.001) and PSC-LT (HR, 1.19; P = 0.002). AIH-LT patients were at increased risk for death (HR, 1.37-1.84; P < 0.001) and graft loss (HR, 1.35-1.80; P < 0.001) from infections compared with all other groups and had a particularly increased risk for lethal fungal infections (HR, 3.38-4.20; P ≤ 0.004). Excluding patients who died within 90 days after LT, risk of death after AIH-LT was superior compared with AC-LT (HR, 0.84; P = 0.004), worse compared with PBC-LT (HR, 1.38; P < 0.001) and similar compared with PSC-LT (P = 0.93). Autoimmune hepatitis (AIH) patients with living donor liver transplantation (LDLT) showed reduced survival compared with patients receiving donation after brain death (HR, 1.96; P < 0.001). In AIH-LT patients, overall survival is inferior to PBC-LT and PSC-LT. The high risk of death after AIH-LT is caused mainly by early fatal infections, including fungal infections. Patients with LDLT for AIH show reduced survival.