Immunological impact of the CD71+ RBCs: A potential immune mediator in transfusion

Donor - recipient sex - mismatched transfusion is associated with increased mortality. The mechanisms for this are not clear, but it may relate to transfusion-related immunomodulation. Recently, CD71+ erythroid cells (CECs), including reticulocytes (CD71+ RBCs) and erythroblasts, have been identified as potent immunoregulatory cells. The proportion of CD71+ RBCs in the peripheral blood is sufficient to play a potential immunomodulatory role. Differences in the quantity of CD71+ RBCs are dependent on blood donor sex. The total number of CD71+ RBCs in red cell concentrates is also affected by blood manufacturing methods, and storage duration. As a component of the total CECs, CD71+ RBCs can affect innate and adaptive immune cells. Phagocytosed CECs directly reduce TNF-α production from macrophages. CECs can also suppress the production of TNF-α production from antigen presenting cells. Moreover, CECs can suppress T cell proliferation thorough immune mediation and / or direct cell-to-cell interactions. Different in their biophysical features compared to mature RBCs, blood donor CD71+ RBCs may be preferential targets for the macrophages. This report summarizes the currently literature supporting an important role for CD71+ RBCs in adverse transfusion reactions including immune mediation and sepsis.