August 29, 2011

Policy change reduces racial disparity in kidney transplants

A national transplant policy change designed to give African-American patients greater access to donor kidneys has sliced in half the racial disparities that have long characterized the allocation of lifesaving organs, new Johns Hopkins research suggests.

Before 2003, the researchers note, an African-American patient who joined the kidney transplant list on the same day as a white patient would have a 37 percent smaller chance than a white counterpart of getting a transplant. In recent years, the researchers say, that percentage has dropped to 19.

The Johns Hopkins researchers attribute the drop to a 2003 decision by the United Network for Organ Sharing to a change in the relative priority given to tissue matching.

“This is probably the biggest step that the transplant community has taken in recent years to reduce disparities in access to kidney transplants for African-Americans, and the good news is it worked extremely well,” said transplant surgeon Dorry L. Segev, an associate professor of surgery at the Johns Hopkins University School of Medicine and leader of the study published online in the American Journal of Kidney Diseases. “The bad news is, we still have a ways to go.”

From the very beginning of widespread kidney transplants in the United States there has been a racial disparity in who received organs and who died before one became available.

A higher proportion of organ donors are white, and a higher proportion of those needing kidneys are African-American. Matches across race are traditionally more difficult, as physicians have given priority to different types of immunologic compatibility, including whether the organ and the donor share the same human leukocyte antigens, or HLA, proteins on the surface of white blood cells and other tissues in the body that can create organ rejection and other complications. African-Americans and whites typically aren’t HLA matches, particularly one subtype known as HLA-B.

“HLA matching was prioritized under the premise that it would improve outcomes,” Segev said. “But with advancements in immunosuppressants, HLA matching isn’t as important as it once was. If you match by HLA, you might get only slightly better outcomes now. A minimal sacrifice in outcomes has meant a big gain in equity.”

Although the new research from Segev and his colleagues found that the UNOS policy change had a profound effect on racial disparities in kidney transplant, the gap remains. Previous research has shown that African-Americans have been at a disadvantage at every step of the kidney transplant process including the incidence and prevalence of kidney failure, referral for transplant evaluation, placement on the waiting list and obtaining a transplant once on the list.

Segev says that research is needed into why there is still a disparity, and how to ensure even more equitable access to lifesaving organs.

The study was funded in part by the Health Resources and Services Administration.

Others from Johns Hopkins involved in the research are Erin C. Hall, Allan B. Massie, Nathan T. James, Jacqueline M. Garonzik Wang, Robert A. Montgomery and Jonathan C. Berger.