Trends in antigen-negative red blood cell distributions by racial or ethnic groups in the United States

BACKGROUND: The overall number of red blood cell (RBC) units distributed to hospitals throughout the world and in the United States has decreased lately. This study was performed to determine if the number of antigen-negative RBC units distributed to hospitals has followed this trend. STUDY DESIGN AND METHODS: Stratified by ethnicity, data on total RBC distributions and antigen-negative RBC distributions from six large blood collectors in the United States were obtained from 2009 through 2016. An antigen-negative unit was defined as a unit with a specific RBC phenotype that had been specially ordered as such by a hospital. RESULTS: Overall, 10,103,703 RBC units were distributed by these six blood collectors; 650,516 (6.4%) were distributed as antigen-negative units. While the overall number of RBCs distributed decreased by 27.2% between 2009 and 2016, the number of antigen-negative RBC distributions increased by 39.5%. In each year, the majority of the distributed antigen-negative RBCs were donated by whites. However, antigen-negative RBC units from black or African American donors were distributed in a disproportionately high fraction compared to the overall number of RBCs distributed from these donors. Most of the one through four antigen-negative RBCs were donated by whites. However, as antigen matching became more extensive, the proportion of units distributed from black or African American donors increased such that they were the predominant donors of five or more antigen-negative units. CONCLUSION: Blood collectors will need to be aware of the trend of increasing antigen-negative distributions despite decreased overall distributions.