1. Intro to Immunohemato

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