February 7, 2019

New option could increase minority kidney transplants

People with blood type B who received a kidney transplant of blood type A2 kidneys had similar outcomes to those with blood type B who received blood type B kidneys.

People with blood type B who received a kidney transplant of blood type A2 kidneys had similar outcomes to those with blood type B who received blood type B kidneys.

However, hospital costs were significantly higher in the former group, and alternative payment models should be considered, according to the results of a three-year Vanderbilt study.

The study’s finding is significant because only about 15 percent of people generally have blood type B, which is more common in African-Americans. As a result, such populations have historically been transplanted at lower rates than the much more common blood types A and O because fewer organs are available.

Since December 2014, the United Network for Organ Sharing (UNOS) has allowed centers to use blood group A2 kidneys for B recipients without obtaining a waiver, seeking to make more organs available to B patients and reduce disparities in wait times. Vanderbilt’s study sought to determine the results of the policy change.

Lead author David Shaffer, MD, professor of Surgery and chief of kidney and pancreas transplant, notes that of the roughly 1,000 people on the Vanderbilt waitlist for a kidney, more than 400 are African-Americans.

Aligning to the Medical Center’s Strategic Compass, the kidney transplant study represents Discover, Learn and Share.

“This is a significant option for centers to adopt to reduce the disparity and increase access to kidney transplants for blood group B recipients who are principally ethnic minorities,” he said.

The study is published in the Journal of the American College of Surgeons. The other authors, all at VUMC, are Irene Feurer, PhD, research professor of Surgery and Biostatistics; Scott A Rega, MS, research analyst III; and Rachel Forbes, MD, MBA, assistant professor of Surgery.

The study analyzed outcomes just at Vanderbilt between December 2014 and December 2017. Outcomes included patient and graft survival, transplant wait time, serum creatinine and eGFR (estimated glomerular filtration rate), hospital costs, post-transplant anti-A titers, and their change relative to pre-transplant.

Even with the new availability, the study notes a recent UNOS analysis showed only 4.5 percent of waitlisted B recipients were registered as eligible for A2 donor kidneys, the result of issues with titers thresholds, patient eligibility and increased costs.

The study found that A2 to B transplantations cost more money as the result of anti-A titer monitoring and additional immunosuppression. Pre-transplant anti-A titer screening added total costs of $76,550 over the three-year study period, excluding additional coordinator time costs. A2 to B had significantly higher mean transplant total hospital costs ($114,638 vs $91,697 for B to B transplantation) and mean hospital costs net organ acquisition costs ($42,356 vs $20,983).

Transplant programs, regulators and payors will need to weigh improved access for minorities with the increased costs involved, the study found.

Shaffer was optimistic about the future of A2 to B transplantation.

“This is a significant move at Vanderbilt and our region as over 40 percent of our patients are African-Americans,” Shaffer said. “It should improve access to transplants for our patient population.”