Effect of Match for Ethnicity on Immunologic Events After Heart Transplantation: An Analysis of the UNOS/OPTN Database

s S91 to determine if match for ethnicity led to a decreased rate of either treated rejection or coronary allograft vasculopathy (CAV) after heart transplantation. Methods: Records of patients receiving a heart transplant after 12/31/1995 with recorded values for first-year and late rejection (defined as > 399 days posttransplant) were identified from the UNOS database. Patients receiving repeat and multi-organ transplants were excluded. Follow-up records were collapsed to a single entry for each patient using a Perl script. Rate of treated rejection was computed as: total treated rejection episodes/post-transplant follow-up time (episodes/patient-year). Rate of CAV was computed similarly. Poisson regression was used to estimate the adjusted relative risk (RR) between ethnicity matched and non-matched transplants for each recipient ethnic group. Results: We identified 22,514 patients in the database. Caucasians composed 77.5% of the identified patients, African-Americans 14.3%, Hispanic/Latinos 5.9%, and Asians 2.3%. Match for ethnicity significantly decreased the rate of treated rejection for Hispanic/Latinos, but not for the other ethnic groups. In contrast, match for ethnicity increased the rate of CAV for Caucasians and Asians, but decreased the rate for African Americans and Hispanic/Latinos. Conclusion: Match for ethnicity decreased the rate of treated rejection in Hispanic/Latino patients and decreased the rate of CAV in African American and Hispanic/Latino patients, but increased the rate of CAV in Caucasians and Asians. Further investigation into genetic variation between ethnic groups is needed to understand the mechanisms of the observed disparities in outcomes and guide interventions to reduce them. Relative Risk of Immunologic Events for Ethnicity Matched vs. Non-Matched Transplants Treated Rejection Cardiac Allograft Vasculopathy Ethnic Group Relative Risk 95% Confidence Intervals p-value Relative Risk 95% Confidence Intervals p-value Caucasian (n= 17, 459) 0.992 0.943 1.044 0.766 1.287 1.220 1.357 < 0.001 African American (n= 3, 213) 0.916 0.813 1.031 0.147 0.854 0.740 0.985 0.03 Hispanic/Latino (n= 1, 318) 0.726 0.605 0.872 < 0.001 0.702 0.560 0.879 0.002 Asian (n= 524) 1.115 0.519 2.395 0.779 1.812 1.009 3.252 0.047