Factors influencing monocyte recognition of human erythrocyte autoantibodies<i>in vitro</i>

Erythrocytes, serum, and blood monocytes from patients with erythrocyte autoantibodies were examined by in vitro serologic and cell culture procedures in order to evaluate factors modulating patient mononuclear phagocyte activity. Monocyte recognition of autoantibody-coated erythrocytes was influenced both by antibody titer score and by the monocyte source. The results suggest that patients with low serum autoantibody titer scores and normal monocyte behavior are less likely to destroy autologous or normal donor erythrocytes than are patients with high-serum antibody titer scores or enhanced monocyte activity. We conclude that patient, rather than normal donor monocytes, must be used in cellular assays designed to predict the fate of erythrocytes transfused into patients with erythrocyte autoantibodies.