alloimmune

Immunity to an alloantigen.

• a. hemolytic anemia of the newborn — occurs in humans, where it is also called Rh disease, in foals as a naturally occurring disease, and in pigs and cattle receiving vaccines containing allotypic red blood cell antigens. In naturally occurring Rh-like syndrome, there are usually no untoward consequences for the first pregnancy, but at parturition red blood cells from the offspring enter the maternal circulation and, if the red blood cell antigens differ from the dam, result in the production of antibodies. A subsequent pregnancy from the same mating in which an offspring of the same blood type is produced will result in a hemolytic anemia in the offspring when maternal antibodies are acquired in the colostrum.

  Hemolytic anemia of the newborn. By permission from Tizard IR, Veterinary Immunology An Introduction, Saunders, 2001