ABO-compatible liver allograft antibody-mediated rejection: an update

Area of Science:

• Transplantation immunology
• Hepatology
• Solid organ rejection

Background:

• Liver allografts exhibit inherent resistance to antibody-mediated rejection (AMR).
• Advances in antibody testing, survival expectations, and immunosuppression minimization have renewed interest in liver AMR.
• Understanding liver AMR is crucial for improving long-term transplant outcomes.

Purpose of the Study:

• To review the emerging understanding of antibody-mediated rejection in liver allografts.
• To characterize the phenotypic expressions of liver allograft AMR.
• To highlight similarities and differences between liver AMR and AMR in other solid organs.

Main Methods:

• Review of recent literature on liver allograft antibody-mediated rejection.
• Analysis of clinical and histopathological findings in acute and chronic AMR.
• Comparison of AMR characteristics across different solid organ transplants.

Main Results:

• Two phenotypic expressions of liver allograft AMR are emerging: acute and chronic.
• Acute AMR presents with donor-specific antibodies (DSA), allograft dysfunction, and specific histopathological findings.
• Chronic AMR is linked to class II DSA, fibrosis, and late-onset rejection, with distinct pathological features.

Conclusions:

• Increased precision in DSA characterization and evolving transplant goals have spurred research into liver AMR.
• While sharing pathophysiological similarities with other organs, liver-specific factors are critical for understanding AMR.
• Further research is needed to fully elucidate the mechanisms and management of liver allograft AMR.