No diffuse intrahepatic biliary stricture after ABO-incompatible adult living donor liver transplantation using tailored rituximab-based desensitization protocol

Preoperative Factors Affecting Graft Survival After ABO-incompatible Adult Liver Transplantation

BACKGROUND

Although ABO-incompatible liver transplantation (ABOi LT) has undergone remarkable progress, the prognostic factors are poorly understood. This study aimed to elucidate the preoperative factors affecting graft survival after ABOi LT.

METHODS

Patients who underwent ABOi LT between January 2012 and December 2020 at a single institution in South Korea were retrospectively reviewed. A total of 146 recipients, including 34 patients with graft loss, were analyzed.

RESULTS

In the multivariate Cox proportional hazard model, recipient age (≥55 y; hazard ratio, 2.47; 95% confidence interval, 1.18-5.19; P  = 0.017) and donor ABO type (donor A, hazard ratio, 3.12; 95% confidence interval, 1.33-7.33; P  = 0.009) were significantly associated with an increased risk of graft loss. The most common cause of graft loss was recipient death due to bacterial infection (15/34, 44.1%). Both recipient age and donor ABO type were associated with an increased risk of recipient death due to bacterial infections. The incidence of complications after ABOi LT, including antibody-mediated rejection and diffuse intrahepatic biliary stricture, did not differ according to recipient age or donor ABO type.

CONCLUSIONS

These findings suggest that recipient age and donor ABO type should be considered when preparing for ABOi LT. Careful monitoring and care after transplantation are required for recipients with preoperative risk factors.

Consecutive disruption of intrahepatic bile ducts after ABO-incompatible living-donor re-liver transplantation: A case report

INTRODUCTION

Hyperacute rejection leading to hepatic necrosis or intrahepatic bile duct stricture in ABO incompatible living-donor liver transplant (ABO-i LDLT) has been reported many times. With the advent of rituximab, the incidence of these complications has decreased significantly. However, consecutive biliary disruption after ABO-i LDLT has rarely been reported.

PRESENTATION OF CASE

A female in her 50s with blood type A was admitted to our hospital for ABO-i LDLT due to failure of a graft (refractory ascites [Child-Pugh C(10), MELD 9]) that had been primarily transplanted 20 years ago from her ABO-identical father. Since the living donor was her husband with blood type B, rituximab was administered for ABO-i re-LDLT. After the LDLT, the patient recovered quickly despite bile leakage at the biliary anastomosis. Subsequently, the bile duct of the graft liver was serially disrupted with a bile lake, which required multiple instances of biliary drainage. A liver biopsy was performed and did not show any C4d staining on 195 post-transplant days. The patient ultimately developed sepsis due to cholangitis and expired at 11 months after the re-LDLT and finally C4d was positive on post-mortem biopsy.

DISCUSSION

Advances in ABO-i LDLT, particularly with rituximab, have reduced complications, but consecutive bile duct disruption remains challenging. Despite positive donor-specific antibody, early rejection markers were absent, suggesting complex mechanisms of complication.

CONCLUSION

We herein report a rare case as an important observation that may aid in preventing and treating potentially fatal complications after ABO-i LDLT.

Immunology demystified: A guide for transplant hepatologists

Liver transplantation has become standard practice for treating end-stage liver disease. The success of the procedure relies on effective immunosuppressive medications to control the host's immune response. Despite the liver's inherent capacity to foster tolerance, the early post-transplant period is marked by significant immune reactivity. To ensure favorable outcomes, it is imperative to identify and manage various rejection types, encompassing T-cell-mediated, antibody-mediated, and chronic rejection. However, the approach to prescribing immunosuppressants relies heavily on clinical judgment rather than evidence-based criteria. Given that the majority of patients will require lifelong immuno suppression as the mechanisms underlying operational tolerance are still being investigated, healthcare providers must possess an understanding of immune responses, rejection mechanisms, and the pathways targeted by immunosuppressive drugs. This knowledge enables customization of treatments and improved patient care, even though a consensus on an optimal immunosuppressive regimen remains elusive.

Factors associated with rituximab-mediated B cell depletion in ABO-incompatible adult living donor liver transplantation

Background

Pretransplant therapies such as rituximab and plasmapheresis have led to an increase in ABO-incompatible (ABOi) living donor liver transplantation (LDLT), thus helping to overcome organ shortages. This study evaluated the changes in anti-A/B titers and CD19 levels over time in patients undergoing ABOi LT and aimed to understand the effect of single-nucleotide polymorphisms (SNPs) in Fc gamma receptor (FcγR) on rituximab therapy.

Methods

Two SNPs of FCGR2A (131H/R) and FCGR3A (158F/V) were identified. The clinical data on 44 patients who underwent ABOi LDLT between May 2019 and October 2021 at Seoul National University Hospital were reviewed retrospectively.

Results

Following desensitization with rituximab and subsequent LDLT, the anti-A/B titer recovered within 1 week, but decreased thereafter. The CD19 level increased at 3 months after LT. The genotyping data for FCGR3A (158F/V) indicated that two patients had the V/V genotype, and 42 had the F/V genotype. In the genotyping data for FCGR2A (131H/R), 21 patients had the H/H genotype, three had the R/R genotype, and 20 had the H/R genotype. However, there were no significant differences in anti-A/B and CD19 levels, bacteremia rates, T cell-mediated rejection, antibody-mediated rejection, or the survival rate among the FCGR2A types.

Conclusions

There were significant changes in the anti-A/B titers and CD19 levels over time in each patient after ABOi LDLT. The difference in outcomes following LT according to the FcγR SNP type for rituximab was unclear. Further studies with larger sample sizes are needed to confirm the effect of FcγR SNPs on rituximab therapy.

Pretransplant mycophenolate mofetil may be associated with reduced intrahepatic cholangiopathy in ABO-incompatible liver transplantation

Intrahepatic cholangiopathy is a life-threatening sequela of ABO-incompatible liver transplantation. We analyzed the clinical impact of pretransplant administration of mycophenolate mofetil in reducing intrahepatic cholangiopathy in ABO-incompatible liver transplantation. Patients who underwent living donor liver transplantation between 2010 and April 2022 were included. Pretransplant mycophenolate mofetil was started in November 2020. A comparison between patients who experienced intrahepatic cholangiopathy and who did not among ABO-incompatible transplantation was performed. Recipients of ABO-incompatible transplantations were categorized based on donor surgery into open, laparoscopy without pretransplant mycophenolate mofetil, and laparoscopy with pretransplant mycophenolate mofetil groups. Cox analysis of intrahepatic cholangiopathy was performed. A total of 234 ABO-incompatible transplantations were included. Intrahepatic cholangiopathy occurred in 1.1% (n=1/94), 13.3% (n=12/90), and 2.0% (n=1/50) of patients who received an ABO-incompatible liver with open surgery, laparoscopic donor surgery without pretransplant mycophenolate mofetil and laparoscopic donor surgery with pretransplant mycophenolate mofetil. ( p = 0.001) Multivariable analysis showed that transplantations involving a donor who underwent a laparoscopic hepatectomy and a recipient who did not receive pretransplant mycophenolate mofetil were associated with a higher risk of intrahepatic cholangiopathy (HR=13.449, CI=1.710-105.800, p = 0.02) compared with transplantations from donors who underwent open surgery. Transplantations involving a donor who underwent laparoscopic donor surgery and a recipient who received pretransplant mycophenolate mofetil resulted in no increased risk compared with transplantations from donors who underwent open surgery. (HR=5.307, CI=0.315-89.366, p = 0.25) Laparoscopic donor hepatectomy was a risk factor for intrahepatic cholangiopathy in ABO-incompatible liver transplantation, while pretransplant mycophenolate mofetil was related to risk reduction of intrahepatic cholangiopathy.

The role of Roux-en-Y hepaticojejunostomy for the management of biliary complications after living donor liver transplantation

INTRODUCTION

Post living donor liver transplantation (LDLT) biliary complications can be troublesome over the post-operative course of patients, especially those with recurrent cholangitis or choledocholithiasis. Thus, in this study, we aimed to evaluate the risks and benefits of Roux-en-Y hepaticojejunostomy (RYHJ) performed after LDLT as a last option to deal with post-LDLT biliary complications.

METHODS

Retrospectively, of the 594 adult LDLTs performed in a single medical center in Changhua, Taiwan from July 2005 to September 2021, 22 patients underwent post-LDLT RYHJ. Indications for RYHJ included choledocholithiasis formation with bile duct stricture, previous intervention failure, and other factors. Restenosis was defined if further intervention was needed to treat biliary complications after RYHJ was performed. Thereafter, patients were categorized into success group (n = 15) and restenosis group (n = 4).

RESULTS

The overall success rate of RYHJ in the management of post-LDLT biliary complications was 78.9% (15/19). Mean follow-up time was 33.4 months. As per our findings, four patients experienced recurrence after RYHJ (21.2%), and mean recurrence time was 12.5 months. Three cases were recorded as hospital mortality (13.6%). Outcome and risk analysis presented no significant differences between the two groups. A higher risk of recurrence tended to be related to patients with ABO incompatible (ABOi).

CONCLUSION

RYHJ served well as either a rescue but definite procedure for recurrent biliary complications or a safe and effective solution to biliary complications after LDLT. A higher risk of recurrence tended to be related to patients with ABOi; however, further research would be needed.

Current Status of ABO-incompatible Liver Transplantation

By 2014, strategies to prevent antibody-mediated rejection (AMR) after ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) were established in Japan and expanded primarily to Asia, where LDLT is now the predominant form of LT owing to the scarcity of brain-dead donors. A desensitization protocol consisting of rituximab (375 mg/m 2 ), plasma pheresis, tacrolimus, and mycophenolate mofetil before LDLT, followed by standard immunosuppression, is currently the best option in terms of safety and efficacy. Rituximab administration is now known not to increase the risk of hepatocellular carcinoma recurrence, and the feasibility of rituximab for LDLT for acute liver failure and the need for desensitization before LDLT in children older than 1 y have been documented. Strategies are needed to distinguish patients at high risk of AMR from those at low risk and to adjust immunosuppression to prevent both AMR and infection. Specific single-nucleotide polymorphisms in genes encoding Fcγ receptors affecting the cytotoxicity of rituximab on B cells could be useful for adjusting immunosuppression levels to decrease infectious complications. Immunological accommodation after ABO-I transplantation could be provided by immune factors in both the grafts and recipients.

The fate of donor-type ABO blood group antigen expression in liver grafts in ABO-incompatible adult living donor liver transplantation

BACKGROUND/PURPOSE

Donor-type ABO blood group antigens (dABOAgs) have been detected in ABO-incompatible adult living donor liver transplantation (ABOi ALDLT) grafts, but their fate and role in ABOi ALDLT rejection remain uncertain.

METHODS

The 0-day, <1-month, and 1-year serial liver graft biopsies from 30 ABOi ALDLT recipients were retrospectively evaluated. ABO antigen expression was quantitatively and serially measured by the mean number of positively stained vascular structures (endothelium of the capillaries, arteries, hepatic veins, and portal veins) within the portal tracts (sS).

RESULTS

The dABOAg sS counts of 0-day, <1-month, and 1-year liver graft biopsies (32.3, 20.8, and 20.6, respectively) decreased significantly (p < .001). Early rejection in the <1-month biopsy was observed in 8/30 (26.7%) recipients, four (13.3%) of whom showed antibody-mediated rejection. The sS counts tended to rebound in grafts showing early rejection, with minimal changes from the 0-day to <1-month period, but increased to pre-transplantation levels after 1 year, compared to that in grafts without early rejection (36.0, 20.4, 19.6 vs. 23.7, 21.9, 23.0, respectively; p = .040).

CONCLUSIONS

While dABOAg expression decreased after ABOi ALDLT, recipients showing early rejection showed sustained graft dABOAg expression. Therefore, dABOAg expression may be involved in the mechanism of accommodation in ABOi transplantation.