What ABO (ABO blood group system) blood type is used for the recipient of an ABO-incompatible (ABOi) transplant?

From the Guidelines

The recipient's blood group in an ABO-incompatible (ABOI) transplant remains unchanged, and the procedure works around the incompatibility rather than changing the recipient's blood type. Recipients of ABOI transplants typically have blood types A, B, or O and receive organs from donors with incompatible blood types (such as a type B recipient receiving a type A kidney) 1. To make these transplants possible, recipients undergo desensitization protocols before surgery to reduce anti-donor blood group antibodies. This typically includes plasmapheresis or immunoadsorption to remove existing antibodies, rituximab to prevent new antibody formation, and immunosuppressive medications like tacrolimus, mycophenolate mofetil, and corticosteroids 1.

Some key points to consider in ABOI transplants include:

• The importance of ABO blood group compatibility to prevent hyperacute rejection and graft failure 1
• The use of desensitization protocols to reduce anti-donor blood group antibodies and prevent rejection 1
• The potential for A2 blood type donors to be transplanted into O recipients due to lower blood group antigen expression 1
• The need for careful matching of donor and recipient HLA antigens to reduce the incidence of acute rejection episodes and improve long-term graft survival 1

The goal of these protocols is to lower the recipient's antibody titers to levels that won't cause immediate rejection of the donor organ. This approach has expanded the donor pool significantly, especially important for recipients with rare blood types or those facing long waiting times for compatible organs. According to the guidelines, efforts to transplant kidneys from donors whose blood group is incompatible with the recipient should be considered experimental 1. However, with proper desensitization and immunosuppression, ABOI transplants can be a viable option for patients in need of a transplant.

From the Research

ABO-Incompatible Transplantation

The recipient's blood group in an ABO-incompatible (ABOi) transplant is not explicitly stated in the provided studies as a specific blood group. However, the studies discuss the protocols and outcomes of ABOi transplants.

Blood Group Considerations

• The studies focus on the reduction of isoagglutinin titers to enable successful transplantation across ABO barriers 2, 3, 4, 5.
• The recipient's isoagglutinin titers are reduced through plasmapheresis, immunosuppression, and other treatments to prevent antibody-mediated acute rejection 2, 3, 4, 5.
• The blood group of the recipient is not specified, but the goal is to reduce the isoagglutinin titers to a level that allows for a successful transplant.

Transplantation Protocols

• The studies describe various protocols for ABOi transplantation, including preoperative plasmapheresis, immunosuppression with tacrolimus, mycophenolate mofetil, and methylprednisolone, and the use of rituximab or splenectomy 2, 3, 5.
• The protocols aim to reduce the risk of acute humoral rejection and ensure a successful transplant outcome.

Outcomes and Complications

• The studies report favorable outcomes for ABOi transplants, with patient survival rates of 100% and graft survival rates ranging from 92% to 97% 3, 5.
• Complications such as acute humoral rejection, chronic active rejection, and infections are reported, but the overall outcomes are considered excellent 3, 5.