Rhesus Factor

Name:
Rhesus Factor
Detailed information:
(Rh factor). A substance present in the red blood cells of the rhesus monkey and of 85% of an average, white, American population. Those whose red cells contain this factor are termed Rh-positive; others, Rh-negative. A negative individual may develop anti-Rh antibodies if Rh-positive red cells enter his blood; such antibodies can then agglutinate Rh-positive cells. Hemolytic reactions may thus occur following transfusion of Rh-positive blood cells into a recipient previously sensitized and having Rh antibodies in the serum. Likewise, an Rh-positive fetus, may give rise to antibodies in the blood of an Rh-negative mother; the antibodies, returning into the fetus may then produce the disease erythroblastosis fetalis. There are many subtypes of the Rh factor; these can be distinguished by serologic tests, and the laws of their inheritance have been determined.