VMC 221: Veterinary Immunology and Serology (1+1)

Hemolytic Disease of Newborn (HDN)

HEMOLYTIC DISEASE OF NEWBORN

• Female animals may become sensitized to fetal RBCs leaked into their blood stream through the placenta during pregnancy.
• In such females, these anti-red cell antibodies may then be concentrated in their colostrum.
• When the newborn suckles, these colostral antibodies are absorbed through the intestinal wall and so reach its circulation.
• These antibodies directed against the blood group antigens of the newborn cause rapid destruction of its red blood cells. The resulting disease is called hemolytic disease of newborn (HDN) or neonatal isoerythrolysis.
• For HDN to occur, four conditions should be satisfied.
  • The young animal must inherit a red cell antigen from its sire that is not present in its mother.
  • The mother must be sensitized to this antigen
  • The mother’s response to this antigen may be boosted by transplacental hemorrhage in late gestation
  • The young animal must ingest colostrum containing high titred antibody to its red blood cells.