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HEM 2133
Immunohaematology IImmunohaematology I
Lesson 1: An Introduction to
Immunohaematology
Do you know that
Blood Transfusion
The process of transferring blood or blood-
based products from one person into the
circulatory system of another
Life-saving in some situations, e.g. massive Life-saving in some situations, e.g. massive
blood loss due to trauma
Can be used to
replace blood lost during surgery
treat severe anemia or
thrombocytopenia caused by a blood diseasethrombocytopenia caused by a blood disease
History of Blood Transfusion
1628 British physician William Harvey
discovered the circulation of blood
1658 Microscopist Jan Swammerdam
observed and described red blood cellsobserved and described red blood cells
1665 The first recorded successful blood
transfusion
occurred in England
Physician Richard Lower kept dog alive by
transfusing blood from other dogstransfusing blood from other dogs
1667 Jean-Baptiste Denis in France and
Richard Lower and Edmund King in England
separately reported successful transfusions
from sheep to humans
1818 British obstetrician James Blundell
performed the first successful transfusion of performed the first successful transfusion of
human blood to a patient for the treatment of
postpartum hemorrhage
1873-1880 U.S. physicians attempted
transfusing milk from cows, goats and humans
1884 Saline infusion replaced milk as a
blood substitute due to the increased
frequency of adverse reactions to milk
1900 Karl Landsteiner discovered the ABO 1900 Karl Landsteiner discovered the ABO
blood group received the Nobel Prize in
1930
Following this landmark discovery, other physicians began developing ways to improve transfusion success
Patients blood was mixed with donor blood to look for reactions before transfusion
The inheritance of blood group was worked The inheritance of blood group was worked out
Anticoagulants were developed that could preserve blood for longer periods
The Rh blood group, as well as other minor blood groups, was discovered
Immunohaematology
Immunohaematology is the study of human
blood groups
In the clinical laboratory, the field of
immunohaematology can include:
Evaluation of blood donors
Collection and processing of donor blood
Testing patient blood for blood group antigens
Matching patient with compatible blood
before transfusion
Tissue typing
Forensic studies
Paternity tests
Genetic studiesGenetic studies
Immunohematology/Blood Bank Department
A division of a hospital laboratory
Here blood / components are gathered as a
result of blood donation, processed and stored
for blood transfusion purposes
Proper tests (e.g. blood typing, crossmatching) Proper tests (e.g. blood typing, crossmatching)
are performed reduce the risk of transfusion
events
Provide blood
Donation area attractive, safe, well-lighted,
comfortably ventilated, clean and open at
convenient hours
Personnel friendly, understanding,
professional, well-trainedprofessional, well-trained
Donor selection to protect both the donor
and recipient
Registration
To identify each donor
To track the blood / components
Particulars of donor full name, IC no, age,
sex, race, address, contact nosex, race, address, contact no
Medical history to identify the potential risk
factor that can jeopardize the health of the
donor or the safety of recipients blood
Regular donors produce blood donation
booklet (previous donation 3 months or
more)
Physical Requirements
Routine screening tests:
(a) Haemoglobin (Hb) estimation
(b) ABO/Rh grouping
(c) Pulse(c) Pulse
(d) Blood pressure
(e) Weight
General appearance in good health
Medical history
To identify the potential risk factor that can
harm the health of the donor or the safety
of recipient
Donors must be assured of a private and
confidential interview process for the confidential interview process for the
medical history and the physical
examination
Blood collection
Collected only by trained personnel
Pleasant, safe and convenient as possible for
donors
Must be by aseptic methods, using a sterile, Must be by aseptic methods, using a sterile,
closed system
The phlebotomist wear gloves during the
procedure
Venipuncture
1. Select a large firm vein, pump up the blood
pressure cuff to 40-60 mmHg or apply
tourniquet
2. Scrub the site of puncture and cover with
sterile swabsterile swab
3. Hang the collection bag below the donor
4. Remove the needle cover and pull the donor
skin downward the arm to make the vein firm
and make a clean venipuncture
5. Keep needle in position with sticking
tape/plastertape/plaster
6. Never leave the donor alone in the room during phlebotomy
7. Blood collection bag should be shaken from time to timetime to time
8. Once finish clamp the tubing and cut
9. Make sure release the bp cuff / tourniquet before the needle is removed from the vein
10.Collect samples into the pilot tubes for screening tests
Safety in the Blood Bank
Standard precautions must be followed when
performing all blood bank procedures
Gloves and personal protective equipment
(PPE) must be worn(PPE) must be worn
Exposure control methods, such as working
behind an acrylic safety shield, must be used
to protect against exposure to blood and
blood products
Most reagents used in blood blanking
originates from human blood products
All reagents must be handled as if potentially
infectious
Disposable supplies should be used Disposable supplies should be used
Surfaces should be disinfected frequently
Safety rules must be followed when using
electrical equipment and instrument with
moving parts, such as centrifuges
Quality Assessment
It is crucial to patient well-being that testing
performed in the immunohaematology
department is of the highest quality and
performed with the utmost attention to
accuracyaccuracy
Blood is a living tissue; a blood transfusion is a
tissue transplant
The same precautions must be used with
blood transfusions as with organ transplants
The donor blood must be collected and stored
in a manner that maintains the sterility of the
blood and the viability of the cells
Test results are used to match donor blood to Test results are used to match donor blood to
the patient
Transfusion of the wrong blood into a patient
can cause severe adverse reactions, such as
kidney shutdown, or even death
Strict quality assessment and assurance
procedures must be followed in the blood bank
department
Mandatory quality assessment guidelines include:
Documenting proper working condition of
refrigerators, freezers, water baths, centrifuges
and any other equipment used in preparing,
testing and storing blood components
Monitoring temperatures at all times to
ensure that components are constantly stored
within acceptable temperature ranges
Visual inspection and testing of reagents at
designated intervals and recording results
Observing reagent expiration dates
Running appropriate controlsRunning appropriate controls
Special attention must be paid to patient and
donor blood identification
Tests must be performed following standard
operating procedureoperating procedure
Observation and interpretation of results must
be carefully recorded
Manufacturers instructions must be followed
for the particular reagents used
Human Blood
A unique fluid tissue
Composed of cellular elements suspended in
an aqueous solution of salts and proteins
Transport medium Transport medium
Red Blood Cells Antigens and
Antibodies Antibodies
Antigen
A substance capable of inducing a specific
immune response
Antibody
Antibody
Combine with Ag on cell surface can cause
destructions through complement action
Also neutralize toxins, facilitate phagocytosis
and kill microbesand kill microbes
5 classes IgA, IgD, IgE, IgG, IgM
Antibody
3 types:
Alloantibodies produced after exposure to foreign antigens (of other individual of same species)species)
Autoantibodies produced against self antigens
Xenoantibodies / Heterophil antibodies produced against other individual of different species
For red blood cells,
- Antigen is present on red blood cell
membrane
- Antibody is present in serum / plasma- Antibody is present in serum / plasma
Blood Group Antigens
Include substances on the red blood cells and
on other blood constituents such as
leukocytes, platelets and plasma
Blood groups controlled by a set of genes are Blood groups controlled by a set of genes are
called a blood group system
Chemically, blood group antigens are usually
glycoproteins, lipoproteins or glycolipids in
nature
Blood Group Antibodies
Specific blood group antibodies develop in
response to the antigenic stimulation by a
particular blood group antigen
The level of antibody activity depends on the The level of antibody activity depends on the
immunogenicity of the corresponding antigen
Alloantibodies
Antibodies which are present in some
members of a species, but not all
E.g. anti-A antibodies are present in all human
beings belonging to blood group B and O
Due to the presence of alloantibodies, it is
necessary to select a blood donor who is
negative for the corresponding antigen
Alloantibodies to red cell may be of three types:
1. Naturally occurring the antigenic stimulus is
unknown, e.g. ABO antibodies.
2. As a result of immunization through
transfusiontransfusion
3. Induced by exposure to fetal erythrocytes
either during pregnancy or during delivery
Autoantibodies
An autoantibody is the antibody which is induced by an antigen in the same individual
It also reacts with the same antigen if it is present in other individuals
In some cases, the reaction of the antigen and In some cases, the reaction of the antigen and its autoantibody may not show any demonstrable clinical symptoms
Sometimes such a reaction may lead to hemolytic anemia, leukopenia or thrombocytopenia
Autoantibodies are divided into two general
categories depending on their optimum
reacting temperature
1. Warm autoantibodies
Constitute about 85% of the autoantibodies
Optimal reacting temperature: 37C Optimal reacting temperature: 37C
Generally IgG in nature
Can be detected with the direct antibody test
2. Cold autoantibodies
About 15% of autoantibodies
Generally IgM in nature
Agglutinate red blood cells strongly at 4C,
weakly at 24C and not at all at 37C weakly at 24C and not at all at 37C
It is important to be aware of cold antibodies
when the patients body temperature needs
to be lowered for procedures such as
cardiopulmonary bypass
What are the antigens and antibodies present in
these blood groups?
Blood group Antigen on RBC
membrane
Antibody in the
serum
A
BB
AB
O
Red Cell Ag-Ab Interaction (in vitro)
Sensitization process whereby antibody
binds to antigen on the cell surface
Agglutination process when sensitized cells
come into contact with one another forming come into contact with one another forming
bridges show visible clumps