Broadened Allocation of Pancreas Transplants Across Compatible ABO Blood Types

Area of Science:

• Transplantation immunology
• Organ allocation policy
• Medical simulation modeling

Background:

• Current Organ Procurement and Transplantation Network (OPTN) policies limit certain blood type-compatible simultaneous pancreas and kidney (SPK) transplants.
• Simulations were used to evaluate alternative allocation sequences allowing all clinically compatible ABO transplants.

Purpose of the Study:

• To examine the impact of modified ABO compatibility rules on SPK, kidney (KI), and pancreas alone (PA) transplants.
• To assess changes in transplant volume, patient benefit, and blood type distribution under alternative allocation scenarios.

Main Methods:

• Utilized the Kidney Pancreas Simulated Allocation Model with data from January 1, 2010, to December 31, 2010.
• Included KI, SPK, and PA candidates and recovered organs; a reduced cohort matched the 2015 waiting list volume.

Main Results:

• Alternative sequences (R4, R5) increased SPK transplants and patient life-years, with a corresponding decrease in KI transplants.
• Transplant distribution shifted towards ABO:A, B, and AB, with a decrease in ABO:O across all organ types, most notably for SPK.
• No significant change was observed in PA transplants.

Conclusions:

• Broadened ABO compatibility primarily benefits SPK candidates with blood types A and AB.
• There is a potential for reduced transplant access for ABO:O candidates.
• Modifying allocation sequences can increase annual SPK transplants.