Inflammatory conditions play a role in recurrence of PSC after liver transplantation – an international multicentre study

Post-Transplant Management and Complications of Autoimmune Hepatitis, Primary Biliary Cholangitis, and Primary Sclerosing Cholangitis including Disease Recurrence

Autoimmune liver diseases have unique post-transplant considerations. These recipients are at increased risk of rejection, and recurrent disease may also develop, which can progress to graft loss and increase mortality. Monitoring for and managing these complications is therefore important, though data on associated risk factors and immunosuppression strategies has in most cases been mixed. There are also other disease-specific complications that require management and may impact these decisions, including inflammatory bowel disease in PSC. Further work to better understand the optimal management strategies for these patients post-transplant is needed.

HLA-DPA1*02:01~B1*01:01 is a risk haplotype for primary sclerosing cholangitis mediating activation of NKp44+ NK cells

OBJECTIVE

Primary sclerosing cholangitis (PSC) is characterised by bile duct strictures and progressive liver disease, eventually requiring liver transplantation. Although the pathogenesis of PSC remains incompletely understood, strong associations with HLA-class II haplotypes have been described. As specific HLA-DP molecules can bind the activating NK-cell receptor NKp44, we investigated the role of HLA-DP/NKp44-interactions in PSC.

DESIGN

Liver tissue, intrahepatic and peripheral blood lymphocytes of individuals with PSC and control individuals were characterised using flow cytometry, immunohistochemical and immunofluorescence analyses. HLA-DPA1 and HLA-DPB1 imputation and association analyses were performed in 3408 individuals with PSC and 34 213 controls. NK cell activation on NKp44/HLA-DP interactions was assessed in vitro using plate-bound HLA-DP molecules and HLA-DPB wildtype versus knock-out human cholangiocyte organoids.

RESULTS

NKp44+NK cells were enriched in livers, and intrahepatic bile ducts of individuals with PSC showed higher expression of HLA-DP. HLA-DP haplotype analysis revealed a highly elevated PSC risk for HLA-DPA1*02:01~B1*01:01 (OR 1.99, p=6.7×10-50). Primary NKp44+NK cells exhibited significantly higher degranulation in response to plate-bound HLA-DPA1*02:01-DPB1*01:01 compared with control HLA-DP molecules, which were inhibited by anti-NKp44-blocking. Human cholangiocyte organoids expressing HLA-DPA1*02:01-DPB1*01:01 after IFN-γ-exposure demonstrated significantly increased binding to NKp44-Fc constructs compared with unstimulated controls. Importantly, HLA-DPA1*02:01-DPB1*01:01-expressing organoids increased degranulation of NKp44+NK cells compared with HLA-DPB1-KO organoids.

CONCLUSION

Our studies identify a novel PSC risk haplotype HLA-DP A1*02:01~DPB1*01:01 and provide clinical and functional data implicating NKp44+NK cells that recognise HLA-DPA1*02:01-DPB1*01:01 expressed on cholangiocytes in PSC pathogenesis.

Recurrent sclerosing cholangitis post-transplant: increased recurrence rates following re-transplantation

Sclerosing cholangitis recurs in some patients following liver transplantation. These high-risk patients may provide clues to the pathogenesis of this disease.

AIMS

In this single-center study, from a high prevalence area, we investigated the incidence of recurrent sclerosing cholangitis following liver transplantation and re-transplantation.

METHODS

A retrospective cohort study of all patients with primary sclerosing cholangitis transplanted in the Irish National Liver Transplant program between 1993 and 2019.

RESULTS

Recurrent sclerosing cholangitis occurred in 23/112 patients (20.7%). Overall patient survival was similar in the recurrence and non-recurrence groups. Nine patients were re-transplanted for recurrent disease. Patients with recurrence were significantly younger (42.7 +  - 2.5 years vs. 49.3 +  - 1.3 p < 0.05), and colectomy post-transplant was performed more frequently in the recurrence group (6/21 vs. 9/81 p < 0.05). Further recurrence after re-transplantation was identified in 6/9 patients and was identified a shorter time after transplant than the first recurrence (median 41.5 months; range 26-53 vs. median 65.5; range 38: p < 0.05).

DISCUSSION/CONCLUSION

Recurrent PSC following liver transplantation is common, particularly in younger patients. It occurs earlier and is more frequent following a second transplant.

Ileal Pouch-anal Anastomosis in Primary Sclerosing Cholangitis-inflammatory Bowel Disease (PSC-IBD): Long-term Pouch and Liver Transplant Outcomes

OBJECTIVE

To compare the effect of liver transplantation (LT) on ileal pouch-anal anastomosis (IPAA) outcomes in patients with primary sclerosing cholangitis and inflammatory bowel disease (PSC-IBD).

BACKGROUND

Patients with PSC-IBD may require both IPAA for colitis and LT for PSC.

METHODS

Patients with PSC-IBD from out institutional pouch registry (1985-2022) were divided according to LT status and timing of LT (before and after IPAA) and their outcomes analyzed.

RESULTS

A total of 160 patients were included: 112 (70%) nontransplanted at last follow-up; 48 (30%) transplanted, of which 23 (14%) before IPAA and 25 (16%) after. Nontransplanted patients at IPAA had more laparoscopic procedures [37 (46%) vs 8 (18%), P =0.002] and less blood loss (median 250 vs 400 mL, P =0.006). Morbidity and mortality at 90 days were similar. Chronic pouchitis was higher in transplanted compared with nontransplanted patients [32 (67%) vs 51 (45.5%), P =0.03], but nontransplanted patients had a higher rate of chronic antibiotic refractory pouchitis. Overall survival was similar, but nontransplanted patients had more PSC-related deaths (12.5% vs 2%, P =0.002). Pouch survival at 10 years was 90% for nontransplanted patients and 100% for transplanted patients (log-rank P =0.052). Timing of LT had no impact on chronic pouchitis, pouch failure, or overall survival. PSC recurrence was 6% at 10 years. For transplanted patients, graft survival was similar regardless of IPAA timing.

CONCLUSIONS

In patients with PSC-IBD and IPAA, LT is linked to an increased pouchitis rate but does not affect overall and pouch survival. Timing of LT does not influence short-term and long-term pouch outcomes.

Evolving challenges with long-term care of liver transplant recipients

The number of liver transplants (LT) performed worldwide continues to rise, and LT recipients are living longer post-transplant. This has led to an increasing number of LT recipients requiring lifelong care. Optimal care post-LT requires careful attention to both the allograft and systemic issues that are more common after organ transplantation. Common causes of allograft dysfunction include rejection, biliary complications, and primary disease recurrence. While immunosuppression prevents rejection and reduces incidences of some primary disease recurrence, it has detrimental systemic effects. Most commonly, these include increased incidences of metabolic syndrome, various malignancies, and infections. Therefore, it is of utmost importance to optimize immunosuppression regimens to prevent allograft dysfunction while also decreasing the risk of systemic complications. Institutional protocols to screen for systemic disease and heightened clinical suspicion also play an important role in providing optimal long-term post-LT care. In this review, we discuss these common complications of LT as well as unique considerations when caring for LT recipients in the years after transplant.

Primary sclerosing cholangitis and other risk factors for post-transplant lymphoproliferative disease after liver transplantation in adults

Post-transplant lymphoproliferative disease (PTLD) is a rare but serious complication of liver transplantation (LT) with morbidity and mortality. The risk factors for PTLD in adults are ill-defined. This study aimed to assess the risk factors for PTLD after LT in adults. All adult LT recipients between 1986 and 2016 from 2 centers in the Netherlands were included, with follow-up until 2020. PTLD was diagnosed according to the World Health Organization (WHO) classification. Potential risk factors for PTLD were assessed using multivariate Cox regression analysis. A total of 1281 patients were included, of whom 29 (2.3%) developed PTLD. Results show that independent risk factors for PTLD after LT in adults were no Epstein-Barr virus load monitoring strategy, primary sclerosing cholangitis as an indication for LT, era (historic era linked to more intense long-term immunosuppression), and Epstein-Barr virus-seronegative recipient. No other independent risk factors were identified in this study. Of the 207 patients with primary sclerosing cholangitis as an indication for LT, 13 (6.3%) developed PTLD versus 16 out of 1074 (1.5%) patients with other underlying liver diseases (log-rank p <0.001). The yearly PTLD incidence was higher in the first year than in the later years after LT (2.4%/y vs. 0.6%/y) for primary sclerosing cholangitis, but not for other indications (0.16%/y). In Epstein-Barr virus-seronegative recipients PTLD occurred earlier after LT, while in 97% of seropositive recipients it could occur very late after LT.

Selected Aspects of the Intricate Background of Immune-Related Cholangiopathies-A Critical Overview

Primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are rare immune-related cholangiopathies with still poorly explained pathogenesis. Although triggers of chronic inflammation with subsequent fibrosis that affect cholangiocytes leading to obliteration of bile ducts and conversion to liver cirrhosis are unclear, both disorders are regarded to be multifactorial. Different factors can contribute to the development of hepatocellular injury in the course of progressive cholestasis, including (1) body accumulation of bile acids and their toxicity, (2) decreased food intake and nutrient absorption, (3) gut microbiota transformation, and (4) reorganized host metabolism. Growing evidence suggests that intestinal microbiome composition not only can be altered by liver dysfunction, but in turn, it actively impacts hepatic conditions. In this review, we highlight the role of key factors such as the gut-liver axis, intestinal barrier integrity, bile acid synthesis and circulation, and microbiome composition, which seem to be strongly related to PBC and PSC outcome. Emerging treatments and future therapeutic strategies are also presented.