What are the differences in graft and patient survival rates between ABO (Blood Type) incompatible and compatible kidney transplants?

From the Guidelines

ABO-incompatible (ABOI) kidney transplants generally show slightly lower graft and patient survival rates compared to ABO-compatible transplants, but the difference has narrowed significantly with modern desensitization protocols. The most recent and highest quality study on this topic is not directly provided in the given evidence, but based on the available information, it can be inferred that ABOI transplants have approximately 5-10% lower graft survival rates than compatible transplants in the first year post-transplant, with this gap decreasing in centers with extensive ABOI experience 1. Long-term patient survival shows similar patterns, with a small increased risk in ABOI recipients.

Key Considerations

• The desensitization protocol typically includes rituximab, plasmapheresis or immunoadsorption, and maintenance immunosuppression with tacrolimus, mycophenolate mofetil, and corticosteroids.
• IVIG is often administered after each plasmapheresis session to reduce anti-blood group antibody titers.
• Despite slightly inferior outcomes, ABOI transplantation remains superior to remaining on dialysis and waiting for a compatible donor, especially for patients with limited access to compatible organs.
• The primary mechanism of potential graft failure in ABOI transplants involves antibody-mediated rejection due to the presence of natural anti-blood group antibodies.

Management and Outcomes

• Recent studies have highlighted the importance of predicting when kidney transplant recipients will need maintenance dialysis or retransplantation to enable providers to identify patients with failing grafts and optimize management and outcomes 1.
• The definition of a failing kidney allograft should be based on an accurate and personalized prediction of allograft failure calculated from validated and clinically implementable prognostication systems.
• Prognostication includes estimating the trajectory of the decline in GFR to estimate the point of return to kidney replacement therapy, and it accounts for other parameters that may influence that trajectory, such as allograft histology, donor age, circulating anti-human leukocyte antigen donor-specific antibodies (HLA-DSAs), and proteinuria.

Clinical Implications

• The decision to proceed with ABOI transplantation should be made on a case-by-case basis, considering the individual patient's risk factors and the potential benefits of transplantation.
• Clinicians should be aware of the potential risks and benefits of ABOI transplantation and discuss these with patients to ensure informed decision-making.
• Further research is needed to continue improving outcomes for ABOI transplant recipients and to develop more effective desensitization protocols.

From the Research

Graft Survival in ABO-Incompatible Kidney Transplants

• Graft survival rates in ABO-incompatible kidney transplants have been reported to be comparable to those in ABO-compatible transplants, with rates ranging from 92% to 97% 2, 3.
• A study published in 2024 reported a graft survival rate of 100% in patients with very high isoagglutinin titers who underwent ABO-incompatible kidney transplantation with a desensitization protocol 4.
• Another study published in 2011 reported a graft survival rate of 94.4% in patients who underwent ABO-incompatible kidney transplantation with a combination of immunomodulation, plasmapheresis, and immunosuppression 3.

Patient Survival in ABO-Incompatible Kidney Transplants

• Patient survival rates in ABO-incompatible kidney transplants have been reported to be excellent, with rates ranging from 100% to 100% 2, 4, 3.
• A study published in 2012 reported that the outcome of ABO-incompatible kidney transplantation in terms of patient and graft survival is comparable to ABO-compatible transplantation for adult and pediatric recipients 5.

Comparison with ABO-Compatible Kidney Transplants

• ABO-incompatible kidney transplantation has been shown to be a viable option for patients with end-stage renal disease, with outcomes comparable to those of ABO-compatible transplantation 5.
• The use of desensitization protocols and immunosuppression has improved the outcomes of ABO-incompatible kidney transplantation, making it a viable option for patients with incompatible blood types 2, 4, 3.

Risks and Complications

• ABO-incompatible kidney transplantation carries a risk of hyperacute rejection, which can be caused by increased isoagglutinin subclass 6.
• Other complications that can occur in ABO-incompatible kidney transplantation include acute humoral rejection, chronic active rejection, and infections such as BK-virus reactivation and cytomegalovirus viremia 4.