Impact of transfusion on viral load in human immunodeficiency virus infection

Recent research has shown that anemia and transfusion are associated with accelerated mortality in patients with human immunodeficiency virus type 1 (HIV-1) infection. It appears that blood transfusions may directly accelerate HIV-1 disease progression through activation of HIV-1 expression and/or transfusion related immunosuppression. In vitro and in vivo evidence suggests that immunization with common recall antigens (eg, tetanus toxoid) can significantly increase plasma HIV viremia, as well as the in vitro susceptibility of peripheral blood mononuclear cells to acute infection. Allogeneic leukocytes also present an antigenic challenge to HIV-infected mononuclear cells, which may cause them to proliferate and increase viral production. In vitro incubation of HIV-infected mononuclear cells with allogeneic blood components (mainly leukocytes) results in increased viral replication. Whether the effects of transfusion on HIV viral load are due to a reduced immune response and/or activation of the virus itself remains to be determined. An ongoing study is evaluating the effects of depleting leukocytes from blood prior to transfusion in HIV-infected patients. Patients are randomized to receive standard of leukocyte-depleted red blood cell (RBC) transfusions and the effect of transfusion on HIV replication is measured. Preliminary data suggest that leukocyte depletion prior to RBC transfusion does not alter viral replication compared with standard packed RBC transfusions.