Immunohematology is the study of blood groups and blood transfusion. Karl Landsteiner discovered the ABO blood group system in humans. The major blood group systems are ABO and Rh. The ABO system consists of four blood groups - A, B, AB and O based on the presence or absence of A and B antigens on red blood cells. Rh system consists of Rh+ and Rh- blood based on presence or absence of D antigen. Erythroblastosis fetalis is a blood group incompatibility reaction between Rh- mother and Rh+ fetus. It can be prevented by Rh immunoglobulin administration. Blood transfusion requires matching of blood groups to avoid immune reactions.

1. DR. MANISH
TIWARI
TUTOR
MICROBIOLOGY

2. INTRODUCTION
 Immunoheamatology= immuno+ heam+ logy = immune
system, heam= blood, logy= study.
 It is the study of blood group, blood transfusion, blood group
antigen, antigen- antibody reaction and the blood group
disorder is called immunoheamatolgy.
 Ehrlich and Morgenroth was 1st described blood group in goat.
 Karl Landsteiner,a Viennese pathologist , successfully
identified the ABO blood group in human.

3. APPLICATION IN ....
1. Transfusion of blood & its components
2. Diagnosis, prevention & management of immunization
associated with pregnancy
3. Leukocyte testing for organ transplantation
4. Laboratory resolution of parentage problems

4. AGGLUTINATION
 Agglutination reactions involve
particulate antigens capable of
binding antibody molecules.
 Since antibody molecules are
multivalent, suspended particulate
antigens form large clumps or
aggregates, easily visible without
magnification, when exposed to
specific antibodies.

5. COMPLETE OR INCOMPLETE ANTIBODIES
1. Complete antibody: which is
capable of agglutinating cells
in physiological saline.
2. Incomplete antibody: it is
bind to erythrocyte or bacteria
but does not produce
agglutination.

6. BLOOD GROUP SYSTEMS
1. ABO BLOOD GROUP
2. Rh BLOOD GROUP SYSTEM
3. OTHERS
A. MNS
B. I/i
C. DUFFY
D. KELL
E. KIDD
F. P
G. LUTHERAN
H. LEWIS

7. 1. ABO BLOOD GROUP SYSTEM
 It contain four blood groups,
that is determined by presence
or absence of two distinct
antigens, A and B, on the
surface of erythrocytes. And
there crossponding antibodies
in the serum.
 If the blood group antigen is
the present on the RBC then
the crossponding antibody
would be absent in the serum.

8. GROUP- A
 Express A antigen on RBC surface
 Genotypes AA or AO
 Have naturally occurring, clinically significant, predominantly IgM
(with a small amount of IgG) antibodies against type B (anti-B)
Subgroups:
A1 (80%)
A2 (20%)
 Significance: some with A2 have antibodies against the A1
subgroup (anti-A1)

9. GROUP -B
 Express B Ag on RBC surface
 Genotypes BB or BO
 Have naturally occurring
clinically significant,
predominantly IgM (with a
small amount of IgG)
antibodies against type A cells

10. GROUP- O
 Have neither A nor B antigens on their RBC
 Genotype OO (“universal donors”)
 Have naturally occurring, clinically significant, very high titer,
anti-A, anti-B and anti-A,B antibodies
 Maternal anti-A,B can cross the placenta to cause hemolytic
disease of the newborn
 Group O cells have the most H antigen

11. GROUP -AB
 Express A and B Ag on
RBC surface
 Genotypes A1B or A2B
 have no ABO antibodies
(“universal recipients”)

12. OTHER BLOOD GROUP SYSTEMS:
 Kell (K,k,Kx)
 Duffy (Fy)
 Kidd (Jka, Jkb)
 MNSs
 P
 Lewis (Le)
 Lutheran (Lu)

13. NATURAL ISOANTIBODIES
 Anti a and anti b isoantibodies are called natural antibodies
because they are seen to arise without antigenic stimulation.
 They are igM in nature and it produced by the age of 6
months.
 ABO in other animal:- it is also present in the some other
animals for example rodents and apes, such as chimpanzees,
and gorillas.

14. H- ANTIGEN
 Seen on RBC of ABO-Universal distributed
 BOMBAY (Oh)PHENOTYPE:
 Patients lack the H gene and therefore cannot make H antigen, A
or B antigen on their red cells
 Have very strong anti-A, anti-B, and anti-H and can only receive
cells from a Bombay donor

15. DISTRIBUTION OF BLOOD GROUPS IN INDIA
 A recent study done in the north India had shown that
group B is the commonest (35%), group O (30%), A
(21%) and AB (14%).
 Previous study done in south India had shown blood
group O is the most common, and these all
difference are due to diversity of race, religion and
creed.

16. RH BLOOD GROUP SYSTEM
 Most important blood group system in humans after ABO system.
 So named because the antibody against this Rh blood group
antigen was first prepared in Rhesus monkey by Landsteiner and
Wiener.
 At present, the Rh blood group system consists of 50 blood-group
antigens, among which the five antigens D, C, c, E, and e are the
most important.
 Commonly used terms Rh factor, refer to the D antigen only. Rh
positive and Rh negative denote presence or absence of Rh antigen
on the surface of RBCs.

17.  Unlike ABO system, there are no natural Rh antibodies in our
blood.
 In India, about 95% of individuals have Rh positive blood group;
the remainder (5%) are Rh negative.
 Rh blood group system has two important clinical applications:
o Role in blood transfusion
o Role in causing hemolytic disease of the newborn (or
Erythroblastosis fetalis)

18. ERYTHROBLASTOSIS FETALIS
 When the mother is Rh-negative and the father is Rh-positive, the
fetus can inherit the Rh factor from the father. This makes the fetus
Rh-positive.
 During delivery, the Rh positive blood may be passed into maternal
circulation.
 The mother being Rh-negative, may develop antibodies to an Rh-
positive fetal RBCs.
 Anti-Rh antibodies are produced only after exposure to Rh-antigen
(from Rh-positive fetus to Rh-negative mother or mismatched
transfusion) and take some time to generate anti-Rh IgG which
can cross the placenta.

19.  Maternal Rh antibodies fail to lyse fetal RBCs during the first
Rh-incompatible pregnancy.
 During the subsequent pregnancies with a Rh positive fetus,
the Rh antibodies being IgG in nature, can cross the placenta
from mother to fetus and can destroy the fetal RBCs.
 Condition is called as haemolytic disease of newborn.
 Can become severe enough to cause serious illness, brain
damage, or even death of the fetus or newborn.

21. SYMPTOMS
 Symptoms of erythroblastosis fetalis during pregnancy may show
up during routine testing.
 These include:
 yellow amniotic fluid with traces of bilirubin from an
amniocentesis procedure that tests the amniotic fluid
 an enlarged liver, spleen, or heart
 a buildup of fluid in the abdomen, lungs, or scalp, detectable
through an ultrasound scan during pregnancy

22.  Newborns with the condition may display visible symptoms as
well as some that show up on scans, such as:
 pale skin
 yellow amniotic fluid, umbilical cord, skin, or eyes, either at birth
or within 24 to 36 hours of delivery
 spleen or liver enlargement

23. COMPLICATIONS
 Complications experienced by the fetus may include:
 mild-to-severe anemia
 jaundice
 severe anemia alongside liver and spleen enlargement
 Hydrops fetalis is another severe complication that causes
fluid to build up in fetal tissues and organs as a result of heart
failure. This is a life-threatening condition.

24.  Complications in a newborn may include:
 severely high levels of bilirubin, with accompanying jaundice
 anemia
 liver enlargement
 A buildup of bilirubin in the brain can lead to a complication
called kernicterus, leading to seizures, brain damage, deafness,
or death.

25. DIAGNOSIS
 The first step in diagnosing erythroblastosis fetalis is to determine
whether the cause is Rh incompatibility.
 antibody-screening test in the first trimester. They may repeat the test at
28 weeks of gestation and may also test the Rh factor of the male
partner.
Fetal testing may include:
 an ultrasound
 fetal middle cerebral artery blood flow measurement, to test blood
movement in the brain
 fetal umbilical cord blood testing, to examine the content of blood from
the fetus

26. In the newborn
 blood group and Rh factor
 red blood cell count
 antibodies and bilirubin levels

28. TREATMENT
 Treatment may include a fetal blood transfusion and delivery of
the fetus between 32 and 37 weeks gestation.
 Treatment options for newborns with the condition include:
 blood transfusion
 intravenous (IV) fluids
 managing breathing problems
 IV immunoglobulin (IVIG)
 The goal of IVIG antibody therapy is to reduce the breakdown of
red blood cells and levels of circulating bilirubin.

29. PREVENTION
 Erythroblastosis fetalis is a preventable condition.
 A medication called Rh immunoglobulin (Rhig), also known as
RhoGAM, can help prevent Rh sensitization.
 This medication prevents the pregnant woman from developing
Rh-positive antibodies.
 Women at risk for Rh sensitization should receive RhoGAM doses
at specific times during their pregnancy and after delivery.

30.  at 28 weeks of gestation
 72 hours following delivery, if the newborn is Rh-positive
 within 72 hours of a miscarriage, abortion, or ectopic pregnancy
 following an invasive prenatal test, such as an amniocentesis or
CVS
 after any vaginal bleeding
 If a woman has a pregnancy that extends beyond 40 weeks, the
doctor may recommend an additional dose of RhoGAM.

31. SAFE BLOOD TRANSFUSION PRACTICES
 The recipient's plasma should not contain any antibodies that
will damage the donor's RBCs.
 The donor plasma should not have any antibodies that will
damage the recipient's RBCs.
 The donor red cells should not have any antigen that is lacking
in the recipient RBCs. If the transfused cells possess a 'foreign
antigen' it will stimulate an immune response in the recipient.

32. SELECTION OF BLOOD GROUP FOR
BLOOD TRANSFUSION
 Universal donor - ‘O’ blood group. Because they do not
possess either A or B antigen; hence they are generally safe.
o The anti-A and anti-B antibodies in the transfused O blood
group are diluted in recipient’s serum, do not ordinarily
cause any damage to the red cells of the A or B blood group
recipients.

33.  Dangerous O group:
o Observed that if the anti-A and anti-B antibody titers are high
(1 :200 or above) in the serum of the individuals with O blood
group.
o Transfusion of such blood may result in damage to recipient’s
RBCs.
o Should not be used for transfusion.

34.  Universal recipients:
o Individuals with AB blood group do not have both A and B
antibodies in serum.
o They can receive any other blood group.
o Hence they are called as Universal recipients.

35. TRANSFUSION REACTIONS-
IMMUNOLOGICAL COMPLICATIONS
 Acute haemolytic reactions:
o Occurs as a result of mismatched blood transfusion.
o The RBCs undergo intravascular haemolysis or they
may be coated by antibodies and engulfed by
phagocytes, removed from circulation and subjected to
extravascular lysis.

36. o Symptoms - fever, chills, chest pain, back pain,
haemorrhage, increased heart rate, dyspnoea, hypotension
and rarely kidney injury.
o When transfusion reaction is suspected, transfusion should
be stopped immediately, and blood should be sent for tests
to evaluate for presence of hemolysis.
o Treatment is supportive.

37.  Delayed hemolytic reactions - occur in some cases of mismatched
blood transfusion. Mechanism similar to acute hemolytic reactions,
but they are milder and occur late.
 Febrile non-hemolytic reactions - most common type, occur due to
the release of inflammatory chemical signals by WBCs present in
stored donor blood.
 Allergic reactions occur when the recipient has preformed
antibodies to certain chemicals in the donor blood, and it does not
require prior exposure to blood transfusions.

38.  Post transfusion thrombocytopenia may occur following
transfusion containing platelets possessing surface protein Human
platelet antigen-1a (HPA-1a).
 Transfusion-associated acute lung injury (TRALI)-
Characterized by acute respiratory distress; probably mediated by
anti-HLA antibodies. It is more common in pregnancy

39. TRANSFUSION REACTIONS-
NON-IMMUNOLOGICAL COMPLICATIONS
Infections and iron overload. Bacteria
Infections: • Treponema pallidum
Viruses: • Leptospira interrogans
 Human immunodeficiency viruses
(HIV)
• Borrelia burgdorferi
 Hepatitis B virus (HBV) • Skin flora
 Hepatitis C virus, rarely hepatitis D
and hepatitis A viruses
Protozoa
 Cytomegalovirus (CMV) • Plasmodium species
 Human T-Lymphotropic Virus • Babesia species
 Slow virus causing variant
Creutzfeldt-Jakob disease
• Leishmania donovani
• Toxoplasma gondii
• Trypanosoma cruzi

40. COMMON TESTS USED IN
IMMUNOHEMATOLOGY
1. Coombs Test (Antiglobulin Test)
2. RBC typing
3. Cross matching
4. Antibody Screening
5. Compatibility Testing

41. MCQ
1. Which of the following is not true about blood group B?
a) Universal blood group
b) Have igM
c) Have B antigen
d) Have a antiA antibody
2. Which of the following antibody are responsible for hemolytic
disease of newborn?
a) igA
b) igD
c) igM
d) igG

42. 3. Which of the following statement is true about Rh blood
group?
a) It determine the negative & positive.
b) It consist of 50 blood group antigen
c) Only A
d) A & B
4. Which of the following are immunological complication of
transfusion reaction?
a) Delayed hemolytic reactions
b) Allergic reactions
c) Transfusion-associated acute lung injury
d) All

43. 5. If the blood of two different groups is mixed together, what
problem is observed?
a) Coagulation
b) Agglutination
c) Only B
d) A& B
6. Which of the following is known as universal recipient?
a) A
b) B
c) AB
d) O

44. 7. Which of the following combination of Rh group of mother
and fetus is lethal for fetus?
a) Rh (-) mother & Rh (+) fetus
b) Rh (+) mother & Rh (+) fetus
c) Rh (+) mother & Rh (-) fetus
d) Rh (-) mother & Rh (-) fetus
8. On what basis of blood group is classified?
a) Antigen
b) Antibody
c) Rh factor
d) A&B

45. 9. Which of the following infectious agents are responsible for
transfusion reaction?
a. HIV
b. Toxoplasma
c. CMV
d. All
10. Rh factor of the blood was discovered by:
a) Louis Pasteur
b) Landsteiner and Weiner
c) Janskey
d) None of these

46. 11. Which of the following statement is NOT true?
a) About 95% of individuals have Rh positive blood group; the
remainder (5%) are Rh negative.
b) ABO and Rh groups are based on antigen-antibody reactions
c) People having A-antigen on RBC surface have anti-A antibody in
their plasma.
d) The ABO system was first discovered in 1950s.

47. WRITE SHORT NOTES ON:
1. Hemolytic disease of newborn (7marks)