1. Immune hematology(ABO)
Eman youssif

4. Introduction:
The Kell blood group system is complex and contains many
antigens that are highly immunogenic. These antigens are the
third most potent, after those of the ABO and Rh blood
groups, at triggering an immune reaction.
Antibodies that target Kell antigens can cause transfusion
reactions and hemolytic disease of the newborn (HDN). In the
case of HDN, ABO and Rh incompatibility are more common
causes. However, disease caused by maternal anti-ABO tends
to be mild, and disease caused by maternal anti-Rh can largely
be prevented. The infrequent cases of HDN caused by Kell
immunization tend to result in severe fetal anemia because
maternal anti-Kell target fetal red blood cell (RBC) precursors,
suppressing the fetal production of RBCs.

5. Difference Between Blood Types
O+ and O-
blood group O is the blood group that has neither antigen A
nor antigen B, which is present in blood types A and B
respectively. As far as the Rhesus factor is concerned, a
person is said to be Rhesus positive if he has the D antigen
present on the surface of his red blood cells. If the D antigen
is absent, then the person is said to be Rhesus negative. So, a
person who is O positive does not have antigen A nor antigen
B, but has D antigen present on the surface of his red blood
cells. On the other hand, a person who is O negative, has
neither antigen A or B, nor antigen D present on the surface
of his red blood cells.
Read more at Buzzle: http://www.buzzle.com/articles/what-
is-the-difference-between-blood-types-opositive-and-
onegative.html

6. One of the main purpose of knowing your blood type is that it can help you
determine which blood types you can receive blood from in case of an
emergency where you need blood. Since O+ does not have antigen A nor B, it
cannot receive blood from either blood types A nor B, irrespective of their
Rhesus factors. However, they can receive blood from O+ people and also
from O- people. While O- people do not have the D antigen, they don't have
anti-D antigens either, and therefore they do not agglutinate when they come
in contact with O blood type cells that have D antigen. O- patients however,
can receive blood only from people who have O- blood type. If any other
blood type is introduced into the body of a person who has O- blood type it
can result in transfusion reaction. The bottom line therefore is that people
with blood type O positive can receive blood from people with O positive as
well O negative blood type, but O negative people can only receive blood
from someone with O negative blood type.
Read more at Buzzle: http://www.buzzle.com/articles/what-is-the-difference-
between-blood-types-opositive-and-onegative.html

7. People who have O positive blood type can donate blood to all blood types who have a positive
Rhesus factor, as the surface of O blood cells do not have any antigens, i.e. antigen A nor B, and
that rules out the chances of blood transfusion reaction. Blood type O negative can donate blood
to every blood type, irrespective of the ABO group or the Rhesus group present, this blood type is
not known to react with any of the blood types. Simply put, people with blood type O+ can
donate blood to A+, B+, AB+ and O+ people, while people with blood type O-, which is often
referred to as the universal donor, can donate blood to people with any blood type.
Read more at Buzzle: http://www.buzzle.com/articles/what-is-the-difference-between-blood-
types-opositive-and-onegative.html

8. Fetal-Maternal Hemorrhage and
Stillbirth
Fetal-maternal hemorrhage (FMH) has been of considerable interest and importance to
obstetricians for decades: leakage of fetal cells into the maternal circulation is the
mechanism through which Rh sensitization arises. In addition, more recent data have
shown that when large volumes of fetal blood are lost in this way, then serious and
potentially fatal fetal or neonatal outcomes can result. The Wisconsin Stillbirth Service
Program to this point has not recommended routine assessment for FMH as a possible
cause of stillbirth. Literature review was undertaken in order to determine if this policy
should be changed.
Leakage of fetal red blood cells can begin anytime from the mid-first trimester onward. It
presumably results from a breach in the integrity of the placental circulation. As pregnancy
continues, more and more women will show evidence of fetal red cells in their circulation
so that by term about 50% will have detectable fetal cells. Most of these, however, are
very small leaks; total fetal blood volume lost in this way is 2 milliliters or less in 96-98% of
pregnancies.

9. The Kleihauer–Betke ("KB") test, Kleihauer–Betke ("KB") stain or
Kleihauer test, is a blood test used to measure the amount of
fetal hemoglobin transferred from a fetus to a mother's
bloodstream.It is usually performed on Rhesus-negative mothers
to determine the required dose of Rho(D) immune globulin
(RhIg) to inhibit formation of Rh antibodies in the mother and
prevent Rh disease in future Rh-positive children.

10. Fetal–maternal hemorrhage severity
estimation
To determine if a positive test for FMH should be
considered as the likely cause of fetal death, the
percent of total fetal blood volume lost should be
calculated, making appropriate adjustments based
on the following known relationships:

11. the size of a fetal red blood cell is 1.22 times that of an adult red blood cell;
the KB stain is known to have a mean success rate of 92% in detecting fetal red blood cells;
in a woman at or near term in her pregnancy, the mean volume of maternal red blood cells is
approximately 1800 ml;
the mean fetal hematocrit is 50%; and
at stillbirth, the mean fetal blood volume is 150 frac{ml}{kg}
These constraints can then be applied to yield the formula
PFB = frac{(3200)(FC)}{(FW)(MC)}

12. where
PFB is the percentage of fetal blood lost;
FC is the observed number of fetal red blood cells;
MC is the observed number of maternal red blood cells (N.B. we have that MC = TC - FC, where
TC is the total observed number of red blood cells, both maternal and fetal);
FW is the stillbirth weight of the fetus in kilograms.

13. Part2:Anti-D (Rho)
Immunoglobulin
The development of anti-D antibodies generally
results from feto-maternal haemorrhage (FMH)
occurring in rhesus D (RhD) negative women who
carry an RhD positive fetus. In later pregnancies,
anti-D antibodies can cross the placenta, causing
worsening rhesus haemolytic disease with each
successive rhesus positive pregnancy.

14. References:
http://www.transfusion.com.au/dise
ase_therapeutics/pregnancy/guidelin
Ig-RhD-es