Since the late 1970s, researchers have noted outcome disparities between African-Americans (AAs) who receive kidney transplants compared to outcomes seen in Caucasian-Americans (CAs) receiving kidney transplants. These studies have shown that AAs experience worse graft function and survival due to a mix of environmental, genetic, socioeconomic and be-havioral factors.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services Policy
In 2014, Cleveland Clinic Kidney Transplant Program investigators published a study looking at kidney transplant outcomes between 1995 and 2004 stratified by race and ethnicity. Their findings were similar to earlier studies, except that they found that AAs who received living donor kidneys demonstrated no disparities with regards to graft failure or survival following transplantation compared to CAs. In contrast, they found that AAs who received a kidney from a deceased donor did not do as well as CAs who received a kidney from a deceased donor.
The same research team completed an updated look at Cleveland Clinic kidney transplant outcomes, again stratified by race and ethnicity, between 2003 to 2013. The results were presented at the 2018 American Urological Association Annual Meeting.
“It’s important to do these studies so we can determine what we can do better to advance the science of medicine,” says Charles Modlin, MD, kidney transplant surgeon, urologist, and Founder and Director of the Minority Men’s Health Center, Cleveland Clinic. “With kidney transplants, it’s such a scarce commodity — there are about 120,000 people waiting nationally to receive only about 25,000 kidneys a year — so we want to make sure we get the right organs to the right patients to maximize this life-saving resource.”
Fewer Living Donor Options
Dr. Modlin and colleagues looked at the medical records of 1,400 transplant recipients of which 341 (24.4 percent) self-identified as African-American. Half the recipients had received living donor kidneys and half had received deceased donor kidneys. The mean age of patients in the cohort was 49.9 years old and 38.5 percent self-identified as female.
They found that compared to CAs, AAs had significantly higher body-mass-index (28.2 vs. 27.2 kg/m2), longer time to transplant (3.6 vs. 2.4 years), longer duration of dialysis (1.2 vs. 1.0 years) and a higher percentage of panel reactive antibodies (19.8 percent vs. 13.8 percent). In addition, AAs were more likely to have received hemodialysis (62.4 percent vs. 38.3 percent) and have public insurance (67.4 percent vs. 42.9 percent) compared to their CA kidney transplant recipient counterparts.
Perhaps most importantly — as seen with the 2014 study — AAs were significantly less likely to receive a living donor kidney than CAs (27.6 percent vs. 57.2 percent). However, those who did showed no disparities with CAs in terms of graft survival and function.
“African Americans have fewer living donor options because their loved ones may also be afflicted with kidney disease, diabetes and/or hypertension, which often excludes them from being living donors,” explains Dr. Modlin. “We find instances where there could be living donor options in the family; however, the family may not be aware of the options and benefits of living donor over deceased donor transplantation.
“Some family members may also be suspicious of organ donation and reluctant to step forward,” adds Dr. Modin. “They may not understand that they can donate a kidney and live out their lives normally. We clearly need to do a better job of promoting the benefits and the options of living kidney donation in African-American communities.”
Drug metabolism differences
In addition to being less likely to receive a living donor kidney, the investigators found that AAs were less likely to be compliant with immunosuppressive medications that work to keep the body from rejecting the new kidney.
Dr. Modlin says there are variety of reasons why that might be the case, such as a lack of education about the importance of taking the medications or the cost of medications. Medicare only pays for three years of post-transplant immunosuppression medications, he notes, but some studies have also shown that AAs may need higher doses of certain antirejection immunosuppressive drugs because their livers often metabolize the drugs differently than CAs.
“We may not have a compliance issue at all,” Dr. Modlin acknowledges. “The disparity may be related to differential metabolism of the immunosuppressive medications in African-Americans.”
The study also uncovered: CAs almost exclusively received kidneys from other CAs and they were more likely to receive better functioning kidneys based on serum creatinine levels compared to those received by AAs. In addition, CAs and AAs did not experience lower graft function when they received kidneys from “expanded criteria” deceased donors — which represent kidney donors over the age of 60 or over the age of 50 with high-blood blood pressure, a creatinine greater than or equal to 1.5 or death resulting from a stroke.
Controlling comorbidities key
Better control and management of disease will result in better quality of life and better function of donated kidneys for all transplant patients, Dr. Modlin suggests. “The lesson of this study is that the health care community needs to strive to prevent the onset of kidney disease in the first place by increased efforts going toward prevention of and control of patients’ diabetes, high blood pressure and other comorbidities.
“We have to continue to give deceased donor kidneys to African-Americans because they have fewer living donor options, but we also have to help patients have better outcomes with those kidneys and encourage African-Americans to seek living donor kidney transplantation options through education of their families and communities about the merits of living donor kidney transplantation over deceased donor kidney transplantation.”