Antidonor antibodies are present in the circulation of the host before transplant: multiparous women who have anti-HLA antibodies against paternal antigens shed from a fetus exposure to foreign HLa from prior blood transfusions host who has already rejected an organ transplantAntidonor antibodies are present in the circulation of the host before transplant: ▪multiparous women who have anti-HLA antibodies against paternal antigens shed from a fetus. ▪exposure to foreign HLA from prior blood transfusions. ▪host who has already rejected an organ transplant