Transcript CLS 2215 Principles of Immunohematolgy

IMMUNOHEMATOLOGY
By
E. Salehi Ph.D.
Assistant prof.
Department of Immunology
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History
ABO System Phenotype
ABO System Genotype
Rh system
Other Blood Groups
Blood Group detection and incompatibility
Hereditary Newborn Disease HDN
Blood Transfusion
Karl Landsteiner (1868-1943)
• Discovered ABO blood
groups, 1900
• Nobel Prize, 1930
Red Blood Cell
Membrane
Components
Biological Functions of Blood group
Systems
 Functional Diversity
 Transporters/Channels
 Transporting Water-Soluble molecules/compounds
 Rh, Colton, Diago, Kx, Kidd
 Receptors
 Biological
 Duffy, Knops, Indian
 Microbial
 MNS, P, Lewis, Duffy, Cromer
 Adhesion Molecules
 Leuthran, Xg, L-W, Indian
 Role in Complement Pathway
 Chido/Rodgers, Cromer, Knops
 Enzymes
 ABO, P, Lewis, H
 Structural Proteins
 Maintain Shape
 MNS, Diago, Gerbich
• Type .2
3
*PS = oligosaccharide
• Type .1
chain attached to
either
glycosphingolipid
(RBC) or glycoprotein
(secretions).
Type 2 Precursor Chain
Formation of H Antigen
ABO Antigen Genetics
LOCATION
a) The presence or absence of the ABH
antigens on the red blood cell membrane
is controlled by the H gene
b) The presence or absence of the ABH
antigens in secretions is indirectly
controlled by the Se genes.
H Antigen
The H gene codes for an enzyme that adds a sugar
(Fucose) to the terminal sugar of a Precursor
Substance (PS*). The biochemical structure below
constitutes the H Antigen. (h gene is an amorph.)
H gene acts on
a Precursor
substance(PS)*
by adding
Fucose
*PS = oligosaccharide
chain attached to either
glycosphingolipid
(RBC) or glycoprotein
(secretions).
The H antigen is found on the rbc
when you have the Hh or HH
genotypes but NOT from the hh
genotype.
The A antigen is found on the
rbc when you have the Hh, HH,
and A/A, A/O or A/B genotypes.
The B antigen is found on the rbc
when you have the Hh, HH, and
B/B, B/O or A/B genotypes.
Possible Blood group Genotypes
Parent
Allele
A
A
B
O
AA
AB
AO
B
AB
BB
BO
O
AO
BO
OO
ABO Subgroups
• ABO subgroups differ in the amount of
antigen present on the red blood cell
membrane, specifically, they have less - it is
quantitative.
• Subgroups are the results of less effective
enzymes! Not as efficient at converting H
antigens to A or B antigens so fewer are
present on the rbc.
• Subgroups of A are more common than
Subgroups of B.
Subgroups of A
•
The two principle subgroups of A are:
1. A1 and A2
a) Both react strongly with reagent anti-A.
b) To distinguish A1 from A2 red blood cells test
with plant lectin: Dolichos biflorus
c) Approximately 80% of Group A and Group AB
persons red cells are agglutinated by Dolichos
biflorus and can be designated A1 and A1B.
d) The remaining 20% are A2 and A2B.
ABO Subgroups
A2 Phenotype
• A2 persons produce anti-A1 allo-antibodies
(%1-8)
• A2B persons produce anit-A1 allo antibodies
(%22-35)
• Allo-Anti-A1 can cause ABO Discrepancies
(How?) and incompatibility in crossmatching.
It is not considered clinically significant
if it does not react at 37oC.
Number of A antigen
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A1=800000
A2=250000
A3=35000
Ax=4800
Aend=3500
Am=700
‫خصوصیات‬
‫واکنش با آنتی‪A‬‬
‫تعداد‬
‫واکنش بالکتین رقیق شده‬
‫ساختمان آنتی ژن‬
‫فعالیت‬
‫ترانسفرازی‬
‫فلز موردنیاز‬
‫نقطه فوکوسینگ ایزوالکتریکی‬
‫‪A1‬‬
‫‪++++‬‬
‫‪800000‬‬
‫‪A2‬‬
‫‪+++‬‬
‫‪200000‬‬
‫‪+++‬‬
‫‪-‬‬
‫‪TYPE1,2‬‬
‫فعال تر وایده آل‬
‫در‪PH=6‬‬
‫‪TYPE2‬‬
‫فعالیت کم و ایده آل‬
‫در‪PH=7‬‬
‫‪Mn,Mg‬‬
‫‪9-10‬‬
‫تنها‪Mg‬‬
‫‪6-7‬‬
Amount of H Antigen
according to ABO Blood Group
• Blood Group O people
have red blood cells rich
Neither the A or B genes
in H antigen. Why?
have converted the H
antigens to A or B antigens
- just a whole bunch of H!
Greatest
Amount of H
O > A2 > B > A2B > A1 > A1B
Least
Amount of H
Lectin
O cells
A2 cells
A2B
cells
B cells
A1 cells
A1B
cells
Bombay
cells
lectin-H
4+
3+
2-3+
2+
weak to
negative
weak to
negative
negative
negative
negative
negative
positive
positive
negative
Lectin-A1 negative
Formation Of ABO Antigens In
Secretions
Hh
PS2
H Antigen
ABO
ABO on Cells
ABO
PS1
H Antigen
Se se
ABO in secretions
Bombay (Oh) Phenotype
• Results from the inheritance of hh
genotype
– Red blood cells lack H, A and B antigens
– First discovered in Bombay, India
– Red cells are NOT agglutinated with anti-A,
Anti-B or Anti-H (Ulex europaeus - lectin)
– Serum has strong anti-A, Anti-B and anti-H
so they agglutinate ALL ABO blood groups
ParaBombay (Ah) Phenotype
A Mystery….Why “preformed” ?
Ab titer
3-6 mo
5-10 yr
ABO Blood Grouping Reagents
• Forward Grouping
– Reagent Anti-A and Anti-B
• IgM class Monoclonal antibody reagent
• Reverse Grouping
– Reagent A1 and B cells (3-5% suspension)
• Routine tests on donors and patients
must include both the forward and
reverse grouping
Frequency of ABO Blood
Groups
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Group O
Group A
Group B
Group AB
47%
42%
8%
3%
The Rh Blood Group System
• Described by Landsteiner in 1940
• Antibodies produced as a result of pregnancy or
transfusion
• Immune antibodies - IgG
• Can cause haemolytic disease of the newborn
and transfusion reactions
Inheritance of Rh genes
• Fisher-Race theory of inheritance
• Rh antigens produced by three closely linked
alleles C or c, D or d, E or e. (these alleles are
located in 2 locus RHD & RHCE
• We inherit these genes in groups of three from
each parent
• A common combination is CDe/cde
• Other individuals have combinations of cDE,
cde, Cde, cdE
Rh System
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•
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D Positive are either D/D or D/d
D Negative are d/d
85% of the population are D Positive
15% of the population are D Negative
Other Rh antigens discovered and named
C,c,E and e
• Weak D phenotype
• Rhnull
Weak D Phenotype (Du)
The weak D phenotype is thought to occur
by one of three mechanisms:
(a) inheritance of an RHD gene encoding for
a weakened expression of D (DCe or DcE)
(b) interaction of the D gene with other
genes (Dce/Ce)
(c) inheritance of an RHD gene missing
some epitopes. (lack of part of D)
Hemolytic Disease of the Newborn
(HDN
(Erythroblastosis fetalis)
Background
 A French midwife was the first to report hemolytic disease of the newborn
(HDN) in 1609.
 In 1932, Diamond and colleagues described the relationship of fetal
hydrops, jaundice, anemia, and erythroblasts in the circulation, a condition
later called erythroblastosis fetalis.
 Levine later determined the cause after Landsteiner and Weiner discovered
the Rh blood group system in 1940.
 In 1953, Chown subsequently confirmed the pathogenesis of Rh
alloimmunization to be the result of passage of Rh-positive fetal red blood
cells after transplacental hemorrhage into maternal circulation that lacked
this antigen.
Rh Incompatibility
 Expression is limited to RBCs
 Rh positive: 45% are homozygous and 55% are heterozygous
 Rh incompatibility is a condition which develops when there is a difference in
Rh blood type between that of the pregnant mother (Rh negative) and that of
the fetus (Rh positive).
 After the initial exposure to a foreign antigen, the maternal immune system
produces antibodies of the immunoglobulin M (IgM) isotype that do not cross
the placenta, and later it produces antibodies of the IgG isotype that traverse
the placental barrier.
ABO incompatibility
 ABO incompatibility is limited to type O mothers with
fetuses who have type A or B blood
 in type O mothers, the antibodies are predominantly IgM
in nature
 Because A and B antigens are widely expressed in a
variety of tissues besides RBCs, only small portion of
antibodies crossing the placenta is available to bind to
fetal RBCs. In addition, fetal RBCs appear to have less
surface expression of A or B antigen, resulting in few
reactive sites—hence the low incidence of significant
hemolysis in affected neonates.
Causes
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Common causes for HDN
Rh system antibodies
ABO system antibodies
 Uncommon causes
Kell system antibodies
Rare causes
Duffy system antibodies
MNS and s system antibodies
No occurrence in HDN
Lewis system antibodies
P system antibodies
BEFORE BIRTH
Antibodies cause destruction of the red cells
Anemia
heart failure
fetal death
AFTER BIRTH
 Antibodies cause destruction of the red cells
 Anemia
 Heart failure
 Erythroblastosis
 General edema Called hydrops fetalis and
erythroblastosis fetalis
 Build up of billirubin
 Kernicterus
 Severe retardation
Kernicterus due to hyperbilirubinemia due to erythroblastosis fetalis due to Rh incompatibility
:‫بیلی روبین‬
 (1) interruption of normal neurotransmission (inhibits
phosphorylation of enzymes critical in release of
neurotransmitters)
(2) mitochondrial dysfunction
 (3) cellular and intracellular membrane impairment
(billirubin acid affects membrane ion channels and
precipitates on phospholipid membranes of mitochondria
 (4) interference with enzyme activity (binds to specific
billirubin receptor sites on enzymes).
PREVENTION
 Before birth
Work up mother for risk and evaluation of complications
 After birth
Rh immune globulin - IgG anti-D given to prevent primary
immunization
Before birth workup
Identify women at risk
ABO - Rh -(Du) - Antibody screen
based on results continue testing (Handout)
IgM antibodies are insignificant
IgG antibodies - titer - freeze and store retiter with a second sample - looking for a
1:32 rise or change in titer
Before birth workup
titer identifies mothers who need amniocentesis
titer every 4 week until 24th week - then every 2
weeks
amniocentesis is performed after 21st week on
high titer - high mortality
Amniocentesis
Analyze pigment that indicates increased hemolysis
Measure OD from 350 - 700 and plot as a function of
wavelength
Draw straight line and obtain difference in OD at 450
Amniocentesis
Intrauterine transfusions
 Bilirubin
 Hb is below 11 g/dL
 Usually O and compatible with mother’s antibody
 CMV, Hb S, and leukocyte negative
 immediate correction of anemia and resolution of fetal hydrops,
reduced rate of hemolysis and subsequent hyperinsulinemia, and
acceleration of fetal growth for nonhydropic fetuses who often are
growth retarded
After birth
Rh Immune Globulin
Give antenatal 28 -32 weeks
also after amniocentesis - IUT - abortion - ectopic
pregnancy - miscarriage
Each vial contains 300 ugm and will prevent
sensitization by 15 ml RBC or 30 ml whole blood
Post Natal Laboratory Studies
Mother
ABO - Rh - Du (micro) - Antibody screen - Antibody
identification if necessary
Baby
ABO - Rh - Du - DAT for IgG antibodies - elute
DAT positive and identify antibody
CBC
Imaging studies
TREATMENT
Exchange transfusion
Phototherapy
Phototherapy
The following are requirements for exchange
transfusion :
 Severe anemia (Hb <10 g/dL)
 Rate of bilirubin rises more than 0.5 mg/dL/hr
despite optimal phototherapy
 Hyperbilirubinemia
 DAT
Exchange Transfusions Objectives
Decrease serum billirubin and prevent kernicterus
Provide compatible red cells to provide oxygen
carrying capacity
Decrease amount of incompatible antibody
Remove fetal antibody coated red cells
Potential complications of exchange
transfusion include the following:
Cardiac - Arrhythmia, volume overload, congestive
failure, and arrest
Hematologic - Overheparinization, neutropenia,
thrombocytopenia, and graft versus host disease
Infectious - Bacterial, viral (CMV, HIV, hepatitis), and
malarial
Metabolic - Acidosis, hypocalcemia, hypoglycemia,
hyperkalemia, and hypernatremia
Vascular - Embolization, thrombosis, necrotizing
enterocolitis, and perforation of umbilical vessel
Systemic - Hypothermia
Blood banking & transfusion
Blood in History
China, 1000 BC
The soul was contained in the blood.
Egyptians bathed in blood for their health.
Pliny and Celsus describe Romans drinking the blood of
fallen gladiators to gain strength and vitality and to cure epilepsy.
Taurobolium, the practice of bathing in blood as it cascaded
from a sacrificial bull, was practiced by the Romans.
Pope Innocent VIII
“…a Jewish daring innovator,
whose name has not come
down to us in memory of
his deed, proposed to find
the pontiff a fountain of
jouvenance in the blood of
three youths who died as
martyrs to their own
devotion and the
practitioners zeal.”
Drinkard, 1870
HISTORY
1628
Harvey
Discovered Circulation of Blood
1665-’66
Wilkins & Lower Transfusions from dog to dog
1667
Jean-Baptiste Denis Performed first recorded
blood transfusions from animals to humans
1818
James Blundell, Obstetrician
First transfusion of human to human
James Blundell
Animal to Human Transfusion
Early lamb blood transfusion
The Kimpton-Brown
transfusion apparatus was
commonly used before
citration. It consisted of a
paraffin-coated gradient glass
cylinder with a horizontal
side tube for suction. It was
in use until approximately 1918.
Lewisohn’s Method of Transfusion
Blood is collected in a citrated flask….…...and immediately transfused.
Early transfusion: Paris, France
Donors must be:
17 years of age
in good health
weigh at least 40 kg
pass a physical and health history examination
prior to donation
Who should not donate blood?
Anyone who has ever used illegal
intravenous (IV) drugs

Hemophiliacs
Anyone with a positive test for HIV
Anyone who has had hepatitis since his or her
eleventh birthday
Transfusion
Autologus transfusion : it refers to those
transfusions in which the blood donor &
transfusion recipient are the same.
Allogeneic transfusion: It refers to blood
transfused to someone other than the
donor.
Autologous transfusion
Preoperative donation
Blood dilution
Intraoperative blood salvage
Post operative blood collection
Experienced mild side effects by a
donor
Stinging during insertion the needle
Upset stomach
Dizziness
A small amount of bruising
A donor may faint
Having muscle spasm
Suffering damage
No Whole blood BUT blood components
Plastic Blood Bags and Component Separation
Red blood cells
 For chronic anemia
resulting from disorders
 For acute blood loss
resulting from trauma or
surgery
 Shelf life of RBC = 42
days
 Frozen for up to 10 years
Plasma
Contain albumin – fibrinogen – globulins
Usually separated into specific products.
Fresh frozen plasma stored for 1 – 7
years.
Cryoprecipated AHF, rich in certain clotting
factors.( factor VIII , fibrinogen, von
Willbrand factor, factor XIII
AHF prevent or control bleeding in
individuals with hemophilia and von
Willbrand’s disease.
Platelets
 Prevent massive blood
loss resulting from
trauma.
 Maybe obtained from
donor by a process
known as APHERESIS.
 Stored at room
temperature for up to 5
days.
 used to treat
thrombocytopenia.
White blood cells
 Transfused within 24 h after collection.
 Used for infections that are unresponsive to
antibiotic therapy.
 The effectiveness is still being investigated.
Compatibility testing
ABO-Rh blood typing
Antibody screening
Cross-matching
Cross-matching is performed to determine
if the patient has antibodies that react with
the donor’s cells
The risk of infection from transfusion
About 1 in 600,000 units for hepatitis B
About 1 in 2 million units for HIV and
hepatitis C
The greater concern is an ABO
incompatibility and transfusion reactions.
ABO incompatibility occurs when blood
samples from two people with different
ABO blood types are mixed.
Several types of transfusion reactions like
allergic and febrile(characterized by fever)
Treatment will depend on type of reaction
and patient’s symptoms.
Fully automated grouping and antibody screening
Play a game on Blood grouping for blood transfusion
http://nobelprize.org/medicine/educational/landsteiner/index.html