(PART 1) OVERVIEW OF IMPORTANT IMMUNOLOGIC PRINCIPLES AS APPLIED TO BLOOD BANKING

Immunology

• Study of Immune system

• recognition and disposal of foreign materials or antigen

• The body will process this antigens, in order to be disposed

• It has its roots to the study of Immunity

Immunohematology

• Study of blood group specific Antigen and Antibody

• Study of RBC antigen and Antibodies associated with blood transfusion

Blood banking

• Collection, processing, storage, preservation & proper disposal of blood for donation

• The selection of the most appropriate products and transfusion practice based on the lab findings and the patient need

• If you wanted to monitor the effectiveness of transfusion

Antigen

• A.k.a Immunogens

• Substance that binds with an antibody

• This antigen will mount the Immune system

• Substances that bind with T-cell, not only with the Antibofy but also substances that capability to bind with T-cells

• This substances specifically interacts with the cell or substance of the Immune system

Immunogens

• a capable to stimulate antibody production

• A foreign substance that induces a foreign substance

True

TRUE OR FALSE?

ALL Immunogens are ANTIGENS, But NOT ALL Antigens are Immunogens

Foreignness

FACTORS AFFECTING IMMUNOGENICITY

• The ability or capability of an Immunogen to induce antibody production

• They must be recognize by the body as NON-SELF

• AUTOIMMUNE DISEASES → self antigen that produces antibodies. Produce to react with your own antigen

Chemical Complexity

FACTORS AFFECTING IMMUNOGENICITY

• The MORE COMPLEX a substance, the MORE IMMUNOGENIC

• The antigens and antibody should be OPPOSITE charges

• Antigens are mostly NEGATIVE CHARGES

• Antibodies are POSITIVELY CHARGE molecule because of their AMINO GROUP or AMINE

Protein

CHEMICAL COMPLEXITY

• ________ is the most complex and most immunogenic

Carbohydrates

CHEMICAL COMPLEXITY

• The 2nd immunogenic is ______________

Glycoproteins

CHEMICAL COMPLEXITY

• The 3rd immunogenic is ___________

• If you combine Protein and Carbohydrates, it is _______________

Glycolipids

CHEMICAL COMPLEXITY

• The 4th immunogenic is _____________

• it is more immunogenic compared to the Lipids alone

Fatty acids, Lipids, and Nucleic Acid

CHEMICAL COMPLEXITY

• The least Immunogenic are ________, ____________, __________________

High molecular weight

FACTORS AFFECTING IMMUNOGENICITY

• The BIGGER the substance the MORE IMMUNOGENIC it is

• Only small part of the immunogen is actually recognize in the IMMUNE RESPONSE

greater than or 10,000 daltons/kilo daltons

HIGH MOLECULAR WEIGHT

• To be immunogenic it should be ____________________

Digestibility

FACTORS AFFECTING IMMUNOGENICITY

• Also known as Degradibility

• The immunogen needs to be degraded and presented to the cells of the Immune system

• From a large substance, it should be a separated into smaller substances in order to be recognize

• The T-cell requires double recogniztion

• First it requires antigen presenting cells (Macrophages, dendritic cells, B cells)

• It also needs your Major Histocompatibility Complex (MHC)

Dosage and route of Administration

FACTORS AFFECTING IMMUNOGENICITY

• As for the Route of entry of the different antigens in the host cells: INTRAVENOUS, INHALATION, INGESTION

• The more immunogen, the more antigen was introduced to the host, the more Immunogenic it is

Accessibility of Reactive Sites

FACTORS AFFECTING IMMUNOGENICITY

• The RBC antigens or the Blood group specific antigens dictate our blood type, those antigen present in the Red cell

• Red cell serves as a carrier for this antigens

• It is more accessible, since it is normally found on the red cell

Epitope

• serves as a Lock & Key theory, the _____ should be highly specific to the Paratope

• In order of the antigen to produce immune response to be highly specific to the antibody or T-cell receptor

• Antigens are very small, very low molecular weight because the requirement should be at least 10,000 daltons

• portion of a molecule or antigen that binds to an antibody or t cell receptor

Haptens

• If _______ molecules alone, there is no immune response, it requires a carrier molecule in order for it to be responsive or to induce the immune response

• If _______ alone, it will not produce any immune response. But with carrier particle, it can produce an immune response

• Low- molecular weight molecule that alone is too small to stimulate an immune response but can combine with another molecule to induce response

Adjuvants

• give a more effective immune response

• This is a substances normally added to the certain antigen, in order for it to become more immunogenic

• ________alone doesn’t produce an immune response, but ________ + WEAK ANTIGEN will give more responsive or effective immune response

• It is commonly used for Vaccines. They are killed or weak antigens that we are using

• In order for it to become more effective in activating our immune system, they are adding _____

• Critical component especially for inactivating vaccine. They can induce specific immune responses that are more rebust and long lasting

• Compounds that enhance an immune response. They are not immunogenic and they cannot induce an antibody response alone.

Autoantigens

• normally present into our body

• antigens that belong to the host

• Example is the ABO BLOOD SYSTEM. For the ABO antigens, they are normally produce in our cells

• For example also, we have autoantigens that are present to all nucleated cell, we have that antigen

• To all nucleated cell they have specific antigens present, they are normally present in our body BUT they do not produces antibody production

Alloantigens

• from other members of the host’s species, and these are capable of eliciting an immune response

• For example, from the same specie (HUMAN TO HUMAN) they are from other members of our specie. This are capable of eliciting of an immune response.

• If you wanted to be transfuse with blood, you have to ensure that the antigens from the host and antigens from the donor are match.

Heteroantigens

• from other species, such as other animals, plants, or microorganisms.

• this antigens will definitely recognize by your immune system

• For example from a particular animal, you are expose to an antigen from that particular animal, that is foreign to your body and it will elicit an immune response. Your immune system will be activated to produce antibodies

Heterophile antigens

• exist in unrelated plants or animals but which are either identical or closely related in structure

• example for this, the polysaccharide of pneumococcus reacts with Anti-A Antisera

• The polysaccharide of the pneumococcus can react with the Anti-A Antisera, it means if you have infection with this pneumococcal, you will test the blood.

• Example if you are Blood type O, but after adding Anti-A Antisera, there’s a reaction. Because the Anti-A Antisera could react to the polysaccharide of the pneumococcus.

>250, 45

RBC ANTIGENS

• Dictates the Blood Group/ Blood Type of an individual

• There are _______ RBC Antigens that are existing and are group into ___ Blood Group System

• For you to know if there’s reaction, you have to check the presence of Agglutination

Direct Hemagglutination reaction

RBC ANTIGENS

• RBC Antigens are detected through ________________________

Red cell phenotyping

RBC ANTIGENS

• In order for us to detect the different antigens, we have to do _____________________

Anti-Sera

RBC ANTIGENS

• In order for you to detect if there’s presence of antigen, you have to use ______________. Your ___________ will bind to the antigen on the Red cell through Direct Hemagglutination reaction

Slide method

• It is just a QUALITATIVE TEST/ SCREENING TEST

• If there’s a presence (+) or absence (-) of agglutination

• No grading

• Least sensitive

Tube Method

• We can grade the strength of agglutination

• We should follow the correct ration of serum and the cell

• It always be 40:1. 2 drops of Antisera + 1 drop of RCS

Dr. Yves Lapierre in Lyon, France

Who discovered Gel method?

• There is objectivity in grading reactions

• Small amount of sample is used

• Results are stable up to 3 days

3 ADVANTAGES OF GEL METHOD

• Costly

• Required to use special type of centrifuge

2 DISADVANTAGES OF GEL METHOD

Polyacrylamide gel or Agarose Gel

For Gel technology, we used what gel??

Plapp, 1984

SOLID PHASE RED CELL ADHERENCE (SPRCA)

• Discovered by _____ and coworkers in _____

Solid phase red cell adherence (SPRCA)

• one of the reactants, either the antigen or antibody, is immobilized onto a solid medium and assay for either the antibody or antigen in question

• If you have an antigen that specific to the Immobilized body, it will bind to well

• One if the 2 tubeless method, used to improve the sensitivity and specificity in blood group typing

6

Human Leukocyte Antigens (HLA)

• Encoded by MHC genes located on chromosome _____

Human Leukocyte Antigens (HLA)

• present on: ALL NUCLEATED CELLS

• Has a capability to mount an Immune response is link to the group of molecules. They are originally referred as a Human Type Antigen

• Also called as MAJOR HISTOCOMPATIBILITY COMPLEX (MHC). Because they determine whether transplanted tissue is histocompatible, thus, it will be accepted or recognize as foreign and rejected

RBC, WBC, PLATELETS

Whole blood: _____, _______, _________

Platelet refractoriness

• unresponsiveness to platelet transfusion because of the ANTI-HLA that binds and destroys HLA on platelets’ surface.

• The Antibody is ANTI-P1A1 antibodies

Antibodies

• Glycoproteins that are produced in response to antigenic stimulation.

• Also known as: IMMUNOGLOBULINS

• Part of gamma- globulin fraction of serum protein

• Basic functional and structural unit is: MONOMER (Y-shaped molecule)

Plasma cell

ANTIBODIES

• Once the matured B-cells undergo differentaiation to become _________

• The ______________ has a capability to produce antibody or immunoglobulins

IgG, IgM, IgA, IgD, IgE

ANTIBODIES

• Five classes of Immunoglobulins: _________________

Heavy chain

ANTIBODIES

• The differentiation of this classes is based on ________________

IgG

ANTIBODIES

• Among the five classification of the antibodies, ___ is the predominant in the blood/circulation

IgG, IgA, IgM, IgD, IgE (GAMDE)

ANTIBODIES

• Predominant Arrangement: ___________

Kappa or Lambda

Light chains are ___________

Classes of Immunoglobulins

Heavy chains are _____________

Tetrapeptide, Disulfide bond

• Antibodies are composed of 2 heavy peptide chain and 2 light polypeptide chains. That’s why it is considered as ______________

• This chain are connected with each by specific bond, that is the ________________

Light Chain

• Analysis of several Bence-Jones proteins revealed that there were two main types of L chains.

• designated as kappa and lambda (λ).

• The structure of the __________ is not fully discovered until discovery of an abnormal protein produced by the patient with multiple myeloma. The abnormal protein is the Bence-Jones proteins. This proteins has specific characteristic, they precipitate at 60 C then they will dissolve 100 C

Heavy chain

• The remaining amino acids can typically be divided up into three or more constant regions with very similar sequences

• Constant regions of the H chain are unique to each class and give each immunoglobulin type its name

Joint Chain

• will produce pentamer and dimer. The IgG could become dimer, the IgM is pentamer. IgA could be monomer or dimer.

• This is seen only on the IgM and IgA

2:1

The kappa to lambda ratio is ______

Chromosome 2

What chromosome is Kappa?

Chromosome 22

What chromosome is Lambda?

200-220 amino acids

For heavy chain, each contain between ________________

Constant chain

Starting from Amino Acid (111) down to 220 is considered as _______________

True

True or False?

With the different classification of antibodies, all of them has the same constant region

Constant Region

The amino acid sequence of IgG, IgA, IgM, IgD, IgE is the same from the 111 to 220 amino acid, that’s why it is called ___________

Variable region

The first amino acid up to 110 amino acid, called as the _______