a. A type AB person is generally called "the universal recipient," and a person
with type O blood is generally called the "universal donor."
b. A universal recipient is a person whose blood does not try to fight off the
blood cells from any A-B-O source. Thus, it makes no difference which A-B-O type
blood he receives. He can generally accept them all without adverse effect.
c. A universal donor is a person whose blood is well accepted by any A-B-O
type person. This blood generally causes no adverse effects on the blood of any A-B-O
type person who receives it. Because of this unique property, the universal donor is
frequently asked to make blood donations.
1-10. Rh FACTOR
Many other flood factors have been isolated. The first one discovered (and the
most important one) is the Rhesus (Rh) factor. The name "Rhesus" is taken from the
name of the Indian rhesus monkey. This factor was first isolated from experiments with
these monkeys. Each person is either Rhesus positive or Rhesus negative, depending
on whether he has or does not have antigens for the Rh factor. Rh-positive people
have these antigens while Rh-negative people do not (unless they have been
transfused with Rh-positive blood). The amount of transfusion required to produce this
reaction varies with the individual. A true "universal donor" would generally be type O
and Rh-negative. Serious problems because of the Rh factor can occur during
pregnancy if the mother is Rh-negative and he fetus is Rh-positive. Small numbers of
the child's red cells escape from the placenta and enter the mother's blood stream. This
will cause no problem during the first pregnancy, but she will form antibodies. If she is
also carrying a Rh-positive child during the second or subsequent pregnancies, the
antibodies from her blood will attack the blood of the fetus and cause anemia in the
fetus. Some possibilities are open for countering this problem. The baby can be
transfused with Rh-negative blood at birth or anti-Rhesus immune globulin injections
can be given to the mother. The stage of the pregnancy when the situation is
discovered will usually determine which procedure should be used.
1-11. OTHER BLOOD GROUPS
Other factors (or groups) have varying effects on the blood, but none have the
impact of the A-B-O or the Rh factors. These factors have names such as "Cartwright,"
"MN," "Lewis," "He," "Kell," and "Wright." Some factors may cause hemolytic disease in
newborns. Some of these factors may present problems in organ transplants. The
incidence of problems is normal use for blood transfusions is rare, but hemolytic
reactions should be monitored during all blood transfusions. These other factors are
sometimes used to establish or reject the possibility of familial relationships, such as in
cases of disputed fatherhood.