Kidney Week

Abstract: TH-OR135

Improvement in Waiting Times for Recipients of A₂ to B Kidney Transplants: Refining Our Understanding

Session Information

• Policy and Pretransplant Considerations
  November 07, 2019 | Location: 151, Walter E. Washington Convention Center
  Abstract Time: 05:54 PM - 06:06 PM

Category: Transplantation

• 1902 Transplantation: Clinical

Authors

• Gilbert, Alexander, MedStar Georgetown Transplant Institute, Washington, District of Columbia, United States

Alexander Gilbert, MD

• Ormiston, Laurel, Georgetown University School of Medicine, Washington, District of Columbia, United States

Laurel Ormiston,

• Radomski, Shannon, Georgetown University Medical School, Washington, District of Columbia, United States

Shannon Radomski,

• Vranic, Gayle M., MedStar Georgetown Transplant Institute, Washington, District of Columbia, United States

Gayle M. Vranic,

• Thomas, Beje S., MedStar Georgetown Transplant Institute, Washington, District of Columbia, United States

Beje S. Thomas,

• Moore, Jack, Washington Hospital Center, Kensington, Maryland, United States

Jack Moore,

Background

The creation of a new allocation priority in the new Kidney Allocation System (KAS) for transplants from blood group A₂ donors to blood group B recipients has allowed more rapid transplantation of the group B list. However, no analysis has looked at the decrease in waiting times controlling for differences in sensitization or other priority factors (such as HIV or HCV positive kidneys). We undertook to do this type of robust analysis.

Methods

We conducted a retrospective analysis of 396 consecutive recipients who received a deceased donor kidney transplant in the time period from December 4, 2014 (the beginning of KAS) to November 1, 2018. We determined the waiting time based on the distribution pool in which the kidney was allocated and compared patients receiving kidneys in the local or regional blood type B for blood type A₂/A₂B donor only pools with those receiving kidneys within the local, regional, or national blood type identical or permissible pools.

Results

There were a total of 17 transplants of A₂/A₂B organs from deceased donors into blood group B recipients. 15 of the 17 were allocated within the A₂/A₂B pools (the other 2 were allocated in high cPRA pools). In the same period there were 57 B to B transplants of which 37 were allocated in the blood type identical or permissable pools. The 15 patients receiving A₂/A₂B organs had a mean waiting time of 4.97 ± 1.55 years, significantly lower than the 37 patients receiving standard B to B transplants (7.76 ± 3.91 years, p <0.001). This amounted to a 35.9% reduction in waiting time.

Conclusion

The benefits of A₂ to B transplantation in decreasing waiting times to transplant have been thus far underestimated due to the confounding factors of high sensitization and other high priority allocation. An A₂ to B transplant protocol can reduce waiting times by more than a third for hard to transplant patients.

Improvement in Waiting Times for Recipients of blood group A2 kidneys