What a formula change may mean for Black patients in need of a kidney transplant

ROCHESTER, Minn. — Experts are hoping a new requirement that all U.S. transplant centers use a race-neutral formula to determine eligibility for a kidney transplant will improve African American access to lifesaving transplants.

"This is an essential step toward reducing racial inequity in access to kidney transplantation," says Naim Issa, M.D., a Mayo Clinic nephrologist. "The inclusion of race in the calculation of kidney function has been linked to disparities in care for African Americans, including delays in diagnosis of kidney disease and eligibility to be put on the waiting list for a kidney transplant."

Role of race in estimating kidney function

The new requirement, which was recently approved by the Organ Procurement & Transplantation Network's board, centers on how a patient's glomerular filtration rate, or GFR, is calculated. This rate estimates how much blood the kidneys' filtering units clean every minute based on a person's body size.

Some transplant centers, including Mayo Clinic, directly measure the glomerular filtration rate to determine a patient's kidney function. But direct measurement of kidney function is not widely available across laboratories and is cost-prohibitive for routine clinic use. Therefore, many health care professionals rely on calculated estimates of the glomerular filtration rate known as eGFR. This estimate is important because it determines whether a patient qualifies to be put on the transplant waiting list.

Some formulas commonly used to estimate kidney functions include a Black race variable. Those formulas report higher eGFRs for Black people, compared to non-Black people with similar characteristics. Recent research has found that these race-based calculations can end up overestimating a Black patient's kidney function by as much as 16%.

What change means for health equity

Racial disparities surrounding access to kidney transplants remain an issue. African Americans are more than three times as likely to have kidney failure than white people and less likely to be put on a waiting list for a kidney transplant.

Once on a waiting list, Black patients often end up waiting longer than white patients for a kidney transplant. The reason behind these disparities is complex.

African Americans are at high risk for kidney failure due in part to high rates of diabetes and high blood pressure. Recent research also has discovered a genetic predisposition to kidney disease for some people with Western African ancestry. Economic and social conditions also play a role, as does a lack of access to health care and structural racism.

"African Americans are markedly overrepresented among patients on dialysis and are less likely to be referred for or receive a kidney transplant," Dr. Issa says.

Encouraging more diverse donors

Experts are optimistic this transplant policy change will encourage more people, especially people of color, to consider becoming organ donors.

August is National Minority Donor Awareness Month. Of the nearly 90,000 people in the U.S. on the waiting list for a kidney transplant, more than one-third are Black.

While organs are not matched based on race and ethnicity, people will generally have a better chance of matching with someone from a similar racial or ethnic background. While most people in need of a transplant in the U.S. are people of color, 30% of donors come from communities of color.

Mayo Clinic has one of the largest living-donor programs in the country. People can register to become organ donors on the Donate Life America website.

Experts available

These Mayo Clinic experts can discuss the race-neutral requirement, its role in addressing racial inequities in transplants and the need for more diverse organ donors:

• Naim Issa, M.D., nephrologist at Mayo Clinic in Rochester.
• Caroline Jadlowiec, M.D., transplant surgeon at Mayo Clinic in Arizona
• Martin Mai, M.D., nephrologist at Mayo Clinic in Florida

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