Strategies for ABO Incompatible Liver Transplantation

Impact of Baseline Anti-ABO Antibody Titer on Biliary Complications in ABO-Incompatible Living-Donor Liver Transplantation

Background: Although advancements in desensitization protocols have led to increased ABO-incompatible (ABOi) living-donor liver transplantation (LDLT), a higher biliary complication rate remains a problem. This study evaluated the effect of baseline anti-ABO antibody titers before desensitization on biliary complications after ABOi LDLT. Methods: The study cohort comprised 116 patients in the ABO-compatible group (ABOc), 29 in the ABOi with the low titer (<1:128) group (ABOi-L), and 14 in the high titer (≥1:128) group (ABOi-H). Results: Biliary complications occurred more frequently in the ABOi-H group than in the ABOi-L and ABOc groups (7 [50.0%] vs. 8 [27.6%] and 24 [20.7%], respectively, p = 0.041). Biliary complication-free survival was significantly worse in the ABOi-H group than in the other groups (p = 0.043). Diffuse intrahepatic biliary strictures occurred more frequently in the ABOi-H group than in the other groups (p = 0.005). Multivariable analysis revealed that the high anti-ABO antibody titer (≥1:128) is an independent risk factor for biliary complications (hazard ratio 3.943 [1.635-9.506]; p = 0.002). Conclusions: A high baseline anti-ABO antibody titer (≥1:128), female sex, and hepatic artery complications are significant risk factors for biliary complications.

ABO Incompatible Living Donor Liver Transplantation in Children: A Single Centre Experience from India

Background

In recent years, paediatric ABO incompatible (ABOi) living donor liver transplant (LT) has shown promising outcomes and can potentially eliminate organ shortage. This study aims to report paediatric ABOi LT experience, including short- and long-term outcomes.

Methods

It is a single-centre retrospective study. Out of 108 LTs, 20 were done in children. We compared the outcomes between ABOi (n = 20) and non-ABOi (n = 220) paediatric living donor liver transplantation (LDLT) performed during the study period. All the children received pre-LT desensitization therapy comprising rituximab and plasmapheresis targeting pre-LT isohemagglutinin (IHA) titres of ≤1:16.

Results

Out of 239 paediatric LDLTs from 2017 to 2022, 19 children (11 females) underwent 20 ABOi LTs (including one retransplant with an ABOi domino allograft) at a median age of 12 (12, 51) months, with the majority being biliary atresia (60%). The median change in CD19 cell%, CD20 cell%, and IHA titres after rituximab from day -14 to day -1 (before LT) was satisfactory. In the first 3 months following LT, acute cellular rejection, culture-proven sepsis, and biliary and vascular complications were seen in 10%, 20%, 20%, and 15%, respectively. None of the ABOi LT recipients developed antibody-mediated rejection. ABOi LT recipients, as compared to non-ABOi LT recipients, had a higher incidence of bile leaks and prolonged hospital stay, with the rest of the complications, including biliary strictures and long-term outcomes, being comparable. At a median follow-up of 21 (14, 33) months, 4 children expired (21%).

Conclusion

ABOi LT in children shows excellent outcomes and can be performed safely with prior desensitization when a compatible liver is unavailable.

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.