Transplantation of A2 and A2B kidneys from deceased donors into B waiting list candidates increases their transplantation rate.

Transplant centers in the Midwest Transplant Network began transplanting kidneys from A2 or A2B donors into blood group B and O patients in 1986. Since 1991, an OPTN/UNOS variance has permitted us to allocate these kidneys preferentially into B and O waiting list patients. With more than 10 years of experience we have noted the following: 1. Thirty-one percent more blood group B patients were transplanted by allocating them A2 or A2B kidneys from our deceased donors. 2. Ten-year graft survival for B recipients of an A2 or A2B kidney (72%) was equivalent to that for B recipients of a B kidney (69%). 3. Type B recipients of simultaneous pancreas-kidney transplants (n=4) also did well with A2 or A2B organs. 4. Non-A recipients were transplanted only when their anti-A IgG titer history was consistently low (< or =4). 5. Most (90%) blood group B patients had a low anti-A IgG titer history; whereas, only one-third of blood group O patients had a low titer history. 6. Neither ethnicity nor HLA class I sensitization level influenced the anti-A IgG titer history. 7. In an OPO with mostly (87%) white donors, nearly 20% of blood group A donors were A2. 8. Waiting time until transplantation was lower for B patients who received an A2 or A2B kidney than for those who received a B or O kidney. 9. Our OPO blood group B waiting list was reduced from 25 low PRA (<40%) B candidates in 1994 to 4 in July, 2004. 10. Blood group A candidates received 6.4% fewer transplants with our A2/A2B--> B allocation algorithm. 11. Minority patients were transplanted at the same rate when using the A2/A2B--> B allocation algorithm as when using the standard UNOS algorithm for allocating B and O kidneys--> B patients.