Red blood cell transfusions are associated with alterations in self-reactive antibody repertoires of plasma IgM and IgG, independent of the presence of a specific immune response toward RBC antigens.

Immunization to allogeneic RBC antigens occurs in transfused patients, and may be associated with the development of RBC-destructive antibodies directed against autologous RBC. The present study investigates the effect of transfusion of allogeneic RBC on self-reactive antibody repertoires, independent of the presence of a specific immune response directed toward RBC antigens. Antibody repertoires of IgM and IgG in plasma of hematological patients prior to starting a transfusion regime and of hematological patients receiving regular transfusions of leukocyte-depleted RBC were analyzed using quantitative immunoblotting on a panel of antigens derived from tissue and cell extracts, followed by multiparametric statistical treatment of the data. Multiparametric statistical analysis discriminated between self-reactive antibody repertoires of patients prior to starting a transfusion regime and those receiving regular RBC transfusions (IgM, 0.0001 < P < 0.0244/IgG, 0.0002 < P < 0.0088, depending on the tissue extract), whereas antibody repertoires of plasma IgM and IgG toward bacterial antigens were similar between groups of patients (P > 0.05). We conclude that the challenge of the immune system with allogeneic RBC antigens influences self-reactive antibody repertoires of plasma IgM and IgG, independent of the presence of a specific immune response toward RBC antigens.