In 1977, Opelz et al (Transplant Proc 9:137, 1977) introduced research that identified ethnic disparities in the relative risk of graft loss when African American donors or recipients were targeted. Current research from the Organ Procurement and Transplantation Network (OPTN) reveals a continuation of these trends. While 1-year graft survival rates for a kidney are 92.1% for Caucasians, 94.1% for Asians, and 92.9% for Latinos, the comparative rate is 88.9% for African Americans. This study extends research on health disparities by examining relative differences in graft and patient survival rates when the organ donors are African American. A number of factors have been introduced as possible determinants of disparate outcomes by ethnicity in terms of graft survival rates. This descriptive study was designed to test the hypothesis: There are no differences in the relative risks associated with graft survival rates and mortality based upon differences in the ethnicity of the donors.
Data were obtained from the OPTN/United Network for Organ Sharing (UNOS) Registry from April 1, 1994 to December 31, 2000. A total of 118,769 transplants were analyzed, including 77,689 living and deceased donor kidney transplants, 26,124 deceased donor liver transplants, and 14,956 deceased donor heart transplants. A multivariate Cox regression model was used to determine the relative risk of graft loss and cardiac transplant mortality for different ethnicities when the organ donors were African American.
The study found that the relative risk of kidney graft loss was 21.3% (P < .01) higher between African American donors and Caucasian recipients than between Caucasian donors and other recipients. With liver transplants, the use of an African American donor increased the risk of graft loss by 21.5% (P < .001). When African American donors gave kidneys and livers to other African Americans, the relative risks of kidney graft loss were 50.9% higher for a kidney (P < .001) and 36.6% higher for a liver (P < .001) if both the donors and recipients were African American. The relative risk of mortality was 51.3% higher (P < .001) when African American hearts were transplanted into other African Americans. No significant differences existed in terms of the relative risk of cardiac mortality (P < .29) when African American hearts were transplanted into Caucasian recipients. When African American donors provided kidneys and livers to Latinos and Asians, the relative risk of graft loss fell below the rates for Caucasian donors and recipients. However, the differences were not statistically significant.
Our data have identified a pressing need to conduct clinical and prospective research that can isolate the causes of these suboptimal outcomes. This is particularly important since the number of African American organ donors has escalated as a result of recent health outreach and education efforts.