ABO-incompatible organ and bone marrow transplantation: current status

Area of Science:

• Immunology
• Transplantation Medicine
• Pediatric Transplantation

Background:

• ABO-incompatible organ transplantation faces challenges due to preformed antibodies against donor endothelium.
• Graft survival rates for ABO-incompatible transplants are lower than ABO-compatible ones, around 50-60% vs. 70-80% at 1 year.
• Infants and young children exhibit significantly better outcomes, especially in liver and heart transplants.

Purpose of the Study:

• To review clinical and experimental data on ABO-incompatible organ and bone marrow allotransplantation.
• To explore mechanisms of graft survival despite natural anti-carbohydrate antibodies.
• To investigate the potential for B-cell tolerance in infant recipients.

Main Methods:

• Review of clinical and experimental data on ABO-incompatible allotransplantation.
• Analysis of graft survival rates from the Collaborative Transplant Study.
• Examination of immune-manipulation strategies in recipients.

Main Results:

• Approximately one-third of ABO-incompatible organ allografts do not undergo humoral rejection.
• Graft survival rates are considerably improved with immune manipulation but remain inferior to ABO-compatible transplants.
• Infant recipients demonstrate superior graft survival, particularly for liver and heart transplants, hinting at developing B-cell tolerance.

Conclusions:

• ABO-incompatible organ transplantation can succeed without humoral rejection in a subset of patients.
• Immune manipulation improves outcomes, but ABO compatibility remains optimal.
• Infants may develop B-cell tolerance, offering a promising avenue for pediatric allotransplantation.