Autoimmunity after liver transplantation: a frequent event but a rare clinical problem

European Society for Organ Transplantation Consensus Statement on Biomarkers in Liver Transplantation

Currently, one-year survival following liver transplantation (LT) exceeds 90% in large international registries, and LT is considered definitive treatment for patients with end-stage liver disease and liver cancer. Recurrence of disease, including hepatocellular carcinoma (HCC), significantly hampers post-LT outcomes. An optimal approach to immunosuppression (IS), including safe weaning, may benefit patients by mitigating the effect on recurrent diseases, as well as reducing adverse events associated with over-/under-IS, including chronic kidney disease (CKD). Prediction of these outcome measures-disease recurrence, CKD, and immune status-has long been based on relatively inaccurate clinical models. To address the utility of new biomarkers in predicting these outcomes in the post-LT setting, the European Society of Organ Transplantation (ESOT) and International Liver Transplant Society (ILTS) convened a working group of experts to review literature pertaining to primary disease recurrence, development of CKD, and safe weaning of IS. Summaries of evidence were presented to the group of panelists and juries to develop guidelines, which were discussed and voted in-person at the Consensus Conference in Prague November 2022. The consensus findings and recommendations of the Liver Working Group on new biomarkers in LT, clinical applicability, and future needs are presented in this article.

Positive autoantibodies in living liver donors

BACKGROUND

There is a nationwide shortage of organs available for liver transplantation. Living donors help meet this growing demand. Not uncommonly, donors will have positive autoantibodies. However, it is unclear whether donor positive autoantibodies are correlated with worse outcomes following living liver donor transplantations.

AIM

To analyze the significance of positive autoantibodies in donors on post-transplant outcomes in recipients.

METHODS

We performed a retrospective review of living liver donors who had undergone liver transplantation between January 1, 2012 and August 31, 2021. Demographic characteristics and pre-transplant data including antinuclear antibodies (ANA) and anti-smooth muscle antibody titers were collected in donors. Outcomes of interest were post-transplantation complications including mortality, biliary strictures, biliary leaks, infection, and rejection. Pediatric recipients and donors without measured pre-transplant autoantibody serologies were excluded from this study.

RESULTS

172 living donor liver transplantations were performed during the study period, of which 115 patients met inclusion criteria. 37 (32%) living donors were autoantibody-positive with a median ANA titer of 1:160 (range 1:80 to 1:1280) and median anti-SMA titer of 1:40 (range 1:20 to 1:160). There were no significant differences in baseline demographics between the autoantibody positive and negative donors. Post-transplantation rates of death (P value = 1), infections (P value = 0.66), and overall rates of complications (P value = 0.52) were similar between the autoantibody positive and negative groups. Higher incidences of anastomotic strictures and rejection were observed in the autoantibody positive group; however, these differences were not statistically significant (P value = 0.07 and P value = 0.30 respectively).

CONCLUSION

Isolated pre-transplant autoantibody positivity is not correlated to worse post-transplant outcomes in living liver donor transplants.

Autoantibodies to LG3 are associated with poor long-term survival after liver retransplantation

Autoantibodies are detrimental to the survival of organ transplantation. We demonstrated that Angiotensin II Type I Receptor agonistic autoantibodies (AT1R-AA) were associated with poor outcomes after liver retransplantation. To examine the effect of other autoantibodies, we studied a retrospective cohort of 93 patients who received a second liver transplant. Pre-retransplant sera were tested with Luminex-based solid-phase assays. Among 33 tested autoantibodies, 15 were significantly higher in 48 patients who lost their regrafts than 45 patients whose regrafts were still functioning. Specifically, patients with autoantibodies to the C-terminal laminin-like globular domain of Perlecan (LG3) experienced significantly worse regraft survival (p = .002) than those with negative LG3 autoantibodies (LG3-A). In multivariate analysis, LG3-A (HR = 2.35 [1.11-4.98], p = .027) and AT1R-AA (HR = 2.09 [1.07-4.10], p = .032) remained significant predictors of regraft loss after adjusting for recipient age and sex. There were synergistic deleterious effects on regraft survival in patients who were double-positive for LG3-A and donor-specific antibody (DSA) (HR = 5.26 [2.15-12.88], p = .001), or LG3-A and AT1R-AA (HR = 3.23 [1.37-7.66], p = .008). All six double-positive patients lost their liver regrafts. In conclusion, LG3-A is associated with inferior long-term outcomes of a second liver transplant. Screening anti-HLA antibodies and autoantibodies such as LG3-A/AT1R-AA identifies patients with a higher risk for liver transplantation.

Histologic Case Definition of an Atypical Glomerular Immune-Complex Deposition Following Kidney Transplantation

Introduction

Immune-complex deposition in the transplanted kidney can present as well-phenotyped recurrent or de novo glomerular disease. However, a subset, herein termed immune-complex glomerulopathy not otherwise specified (ICG-NOS), defies classification. We quantified, categorized, and characterized cases of transplant ICG-NOS occurring at a single US academic medical center.

Methods

We retrospectively reviewed our single-institution pathology database (July 2007–July 2018) to identify and categorize all cases of immune-complex deposition in kidney allografts (based on immunofluorescence microscopy). We extracted clinicopathologic and outcome data for ICG-NOS (i.e., immune complex deposition not conforming to any well-characterized glomerular disease entity).

Results

Of 104 patients with significant immune deposits, 28 (27%) were classified as ICG-NOS. We created 5 mutually exclusive ICG-NOS categories: Full-house, Quasi-full-house, IgA-rich, C1q-rich, and C1q-poor. Overall, 16 (57%) patients met criteria for definite or possible allograft rejection, including 9 (32%) with antibody-mediated rejection (ABMR), 3 (11%) suspicious for ABMR, 1 (4%) with T-cell–mediated rejection (TCMR), and 9 (32%) with borderline TCMR. After a median follow-up of 2.3 (range, 0.1–14.0) years after biopsy, 7 (25%) allografts had failed and an additional 8 (29%) had persistent renal dysfunction (hematuria, 14%; proteinuria, 21%; and estimated glomerular filtration rate <60 ml/min per 1.73 m², 11%).

Conclusion

In contrast to prior studies, our findings suggest that ICG-NOS is not necessarily a benign glomerular process and that there may be an association between ICG-NOS and alloimmunity. Our immunofluorescence-based classification provides a framework for future studies aiming to further elucidate ICG-NOS pathogenesis and prognosis.

Self-antigens and rejection: a proteomic analysis

PURPOSE OF REVIEW

Allo- and autoantibodies have been found to play important roles in both acute and chronic allograft rejection in organ transplantation, although only recently have non-human leukocyte antigen (non-HLA), nondonor-specific antibodies been given a more in-depth treatment. This review summarizes recent reports about investigations and proteomic approaches to identify self-antigens and corresponding autoantibodies that are associated with acute and chronic allograft rejection. Finally, we discuss the insights gained from these, challenges, and future prospects.

RECENT FINDINGS

Significant discoveries have been made regarding the presence and role of autoantibodies and alloantibodies, both those formed pretransplant and posttransplant, in acute and chronic rejection. These discoveries are made possible because of the publication of the human genome and subsequent development in the ability of expression and analysis of human proteome.

SUMMARY

Antibodies play a critical role in survival and dysfunction of a transplanted kidney. Even though HLA antibodies have been given the majority of the scientific community's attention for the past few decades, antibodies against autoantigens and that of non-HLA origin are gaining attention. Recent publications have identified novel self-antigens that are associated with acute and chronic rejection that have added to our understanding of new players in immune-related transplant rejection.

Autoimmune Hepatitis in the Liver Transplant Graft

Recurrent autoimmune hepatitis (AIH) and de novo AIH are 2 important causes of late graft failure after liver transplantation (LT). Recurrent AIH occurs in patients who undergo LT for AIH. De novo AIH occurs in patients who are transplanted for etiologies other than AIH. Although typically treated with standard treatment for AIH, including corticosteroids and azathioprine, both recurrent and de novo AIH may progress to end-stage liver disease requiring retransplantation.

Recurrence of primary sclerosing cholangitis, primary biliary cholangitis and auto-immune hepatitis after liver transplantation

Liver transplantation is a well-accepted treatment for decompensated chronic liver disease due to primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and auto-immune hepatitis (AIH). Survival after liver transplantation is generally good with 1 and 5-year survival rates around 90% and 70-85%. After transplantation, however, these diseases recur in 8.6-27% (rPSC), 10.9-42.3% (rPBC) and 7-42% (rAIH), and this poses significant challenges in terms of management and graft outcome in these patients. In this review we discuss the incidence, clinical presentation, challenges in diagnosis, reported risk factors and impact on post-transplant outcomes of recurrence of PSC, PBC and AIH after liver transplantation. We also discuss some of the limitations of current investigations and formulate idea's for future research objectives.

Lack of Clinical Relevance of ANA and ASMA Positivity in Patients with Liver Transplantation without a History of Autoimmune Diseases

The relevance of isolated autoimmunity elevation in orthotopic liver transplantation (OLT) patients is unknown. Our aim was to analyse how serum autoantibodies change in time and to evaluate their clinical relevance in OLT patients. Patients were invited to provide samples to evaluate ANA, AMA, ASMA, and LKM at the time of enrolment (T0), after 6 months (T6), and after 12 months (T12). We included 114 patients in the study (76% males, median age 62.5 years), finding isolated elevation of at least one serum antibody in up to 80% of them. We described fluctuating positive autoantibodies in the one year of observation, with only 45.6% of patients positive for ANA and less than 2% positive for ASMA, at all three times. Isolated elevation of tissue antibodies was not related to gender, age, HCC at transplant, early rejection, cause of transplantation, immunotherapy taken, and age at the time of the study. We did not detect a higher prevalence of positive autoimmunity in patients with signs of liver injury. ANA and ASMA evaluation in patients with liver transplantation and no history of autoimmune disease has no clinical relevance, since it varies in time and is not related to any risk factors or liver injury. Routine autoimmunity evaluation should be avoided.

De novo autoimmune hepatitis after liver transplantation: A focus on glutathione S-transferase theta 1

De novo autoimmune hepatitis (DAIH) is a rare clinical condition with features that resemble those of autoimmune hepatitis (AIH) in patients undergoing liver transplantation (LT) for nonautoimmune liver disease. The diagnosis of this entity has been based on the presence of biochemical and histological patterns similar to those observed in the primary AIH, although several considerations must be taken into account. The impact of DAIH on graft survival is relevant, and early diagnosis and treatment is associated with a good longterm outcome. Although glutathione S-transferase theta 1 (GSTT1) alloimmune recognition has been shown to be involved in the pathogenesis of DAIH, further studies are necessary to fully determine its pathogenic mechanisms and risk factors. We review the pathophysiology, the most common histological patterns, the treatment strategies, and the longterm outcomes of DAIH after LT with a special focus on GSTT1. Liver Transplantation 23:75-85 2017 AASLD.

De novo autoimmune hepatitis in liver transplant: State-of-the-art review

In the two past decades, a number of communications, case-control studies, and retrospective reports have appeared in the literature with concerns about the development of a complex set of clinical, laboratory and histological characteristics of a liver graft dysfunction that is compatible with autoimmune hepatitis. The de novo prefix was added to distinguish this entity from a pre-transplant primary autoimmune hepatitis, but the globally accepted criteria for the diagnosis of autoimmune hepatitis have been adopted in the diagnostic algorithm. Indeed, de novo autoimmune hepatitis is characterized by the typical liver necro-inflammation that is rich in plasma cells, the presence of interface hepatitis and the consequent laboratory findings of elevations in liver enzymes, increases in serum gamma globulin and the appearance of non-organ specific auto-antibodies. Still, the overall features of de novo autoimmune hepatitis appear not to be attributable to a univocal patho-physiological pathway because they can develop in the patients who have undergone liver transplantation due to different etiologies. Specifically, in subjects with hepatitis C virus recurrence, an interferon-containing antiviral treatment has been indicated as a potential inception of immune system derangement. Herein, we attempt to review the currently available knowledge about de novo liver autoimmunity and its clinical management.