Development of a significant titer of specific antibody as a result of antigenic stimulation with material contained on or in the red blood cells of another individual of the same species; e.g., isoimmunization is likely to occur when an Rh-negative person is treated with a transfusion of Rh-positive blood from another human being, or an Rh-negative woman has a pregnancy in which the fetus inherits Rh-positive red blood cells.
