isoimmunization
noun
iso·im·mu·ni·za·tion
variants:
or chiefly British isoimmunisation \ ˌī-sō-ˌim-yə-nə-ˈzā-shən 
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Medical Definition of isoimmunization
: production by an individual of antibodies against constituents of the tissues of another individual of the same species (as when transfused with blood from one belonging to a different blood group)
— called also alloimmunization