Comprehensive Immunology, Serology, Blood Banking, and Transfusion Medicine Review

What is the human immune system responsible for?

The human immune system is responsible for the destruction of foreign substances (antigens) and keeping the body safe from injury and infectious agents.

What is immunology?

Immunology is the study concerned with the processes by which all living organisms defend themselves against infection.

What are antigens?

Antigens are substances that are considered foreign to a host.

What are the two main components of adaptive immunity?

The two main components are cellular (T cells and B cells) and humoral (cytokines and antibodies).

What is cellular immunity?

Cellular immunity refers to the immune response that involves T cells.

What is humoral immunity?

Humoral immunity involves non-cellular substances, such as antibodies, that promote immunity.

What are the two categories of immunity?

The two categories are innate immunity (natural or non-specific) and adaptive immunity (acquired or specific).

What is innate immunity?

Innate immunity is the natural or non-specific immunity that is present at birth.

What percentage of lymphocytes are thymus-dependent?

60-80% of lymphocytes are thymus-dependent.

What is the primary function of T cells?

T cells are involved in cell-mediated immune responses and regulate the production of antibodies by B cells.

What is the function of B cells?

B cells produce antibodies in response to foreign agents.

What are the two types of acquired immunity?

The two types are natural and artificial immunity.

What are the two forms of immunity based on what is received?

The two forms are active immunity and passive immunity.

What are some components of innate immunity?

Components include anatomical barriers (skin, cilia, mucus), resident flora, and cellular factors (basophils, eosinophils, neutrophils, monocytes, natural killer cells).

What is an autoantigen?

An autoantigen is an antigen that originates from the person's own body and does not normally evoke an immune response.

What is the significance of autoantigens in autoimmune diseases?

Autoantigens can lead to autoimmune diseases, where damage to organs or tissues results from the presence of autoantibodies or autoreactive cells.

What is a monovalent antigen?

A monovalent antigen is an antigen that has a single epitope.

What is a multivalent antigen?

A multivalent antigen is an antigen with more than one identical epitope.

What are immunogens?

Immunogens are antigens capable of stimulating a host's immune system; all immunogens are antigens, but not all antigens are immunogens.

What are haptens?

Small molecules that are not immunogenic by themselves but can become immunogenic when coupled to a carrier.

What is a carrier in immunology?

A macromolecular substance to which a hapten is coupled to produce an immune response, such as RBC, bacteria, or latex.

What is a soluble antigen?

An antigen that does not have a carrier.

What is a particulate antigen?

An antigen that is attached to a carrier.

Define exogenous antigens.

Antigens that enter the body and circulate in body fluids, including bacteria, viruses, and pollutants.

What are endogenous antigens?

Antigens derived or produced from within the body's own cells.

What are alloantigens?

Antigens that are found in another member of the host's species and can elicit an immune response.

What are heteroantigens?

Antigens of a species different from that of the host, such as those from other animals or microorganisms.

What are heterophile antigens?

Heteroantigens that exist in unrelated plants or animals but are closely related in structure, allowing for cross-reactivity.

What is the significance of Human Leukocyte Antigen (HLA)?

HLA molecules are crucial for antigen presentation and play a role in organ transplantation and disease predisposition.

What are the three classes of HLA?

Class I (A, B, C), Class II (DP, DQ, DR), and Class III (secreted proteins).

What is the role of HLA Class I?

Presents antigens to CD8+ T cells.

What is the role of HLA Class II?

Presents antigens to CD4+ T cells.

What are antibodies?

Immunoglobulins, specifically glycoproteins, that recognize and bind to antigens.

What is a paratope?

The antigen-binding site on an antibody.

What factors affect immunogenicity?

Foreignness, chemical composition, molecular size, molecular complexity, susceptibility to processing, genetic composition, route and dosage.

What are naturally occurring antibodies?

Antibodies that are present without prior exposure to an antigen.

What are immune antibodies?

Antibodies produced after exposure to an antigen.

What is the role of adjuvants in vaccines?

Enhance immunogenicity by prolonging antigen persistence and stimulating lymphocyte proliferation.

What is the ABO blood group system?

A classification system based on the presence of A and B antigens in RBCs and corresponding antibodies in serum.

What is the Rh factor?

An antigen present in Rh positive individuals, with corresponding antibodies absent in their serum.

What is the importance of antigen processing and presentation?

It is crucial for T cell activation and the adaptive immune response.

What is the significance of molecular complexity in immunogenicity?

More complex molecules are generally more immunogenic than simpler ones.

What is the role of antibodies in humoral immunity?

Responsible for antigen recognition, opsonization, and complement activation.

What are the two types of light chains in antibodies?

Kappa and Lambda

What are the five types of heavy chains in antibodies?

Gamma, Alpha, Mu, Epsilon, Delta

Where is the variable region of an antibody located?

In the amino terminal end

What is the function of the constant region of an antibody?

It determines the antibody's class and mediates its effector functions.

What are the two fragments produced by pepsin digestion of antibodies?

Fc' and F(ab)2

What are the three fragments produced by papain digestion of antibodies?

Fab, Fab, and Fc

What is the structure of the fragment antigen-binding (Fab) region?

One light chain and half of a heavy chain

What is the role of the hinge region in antibodies?

It provides flexibility between the CH1 and CH2 domains.

What type of antibodies are typically cold-reactive?

Usually IgM

What type of antibodies are typically warm-reactive?

Usually IgG

What is the molecular weight of IgG antibodies?

150,000

What is the serum half-life of IgM antibodies?

6 days

What is the primary difference between alloantibodies and autoantibodies?

Alloantibodies are produced in response to non-self antigens, while autoantibodies are produced against self-antigens.

What are complement-activating antibodies known for?

They result in intravascular hemolysis and immediate hemolytic transfusion reactions.

What is the classical pathway in complement activation?

A pathway involving a set of serum proteins that promote phagocytosis and inflammatory responses.

What is the role of opsonins in the complement system?

They promote phagocytosis by marking pathogens for destruction.

How does the pH affect antigen-antibody binding?

The optimum pH for binding is between 6.5 and 7.5.

What is the difference between agglutination and precipitation?

Agglutination involves particulate antigens, while precipitation involves soluble antigens.

What is the zone of equivalence in antigen-antibody interactions?

The ideal reactive condition where the number of multivalent sites of antigen and antibody are approximately equal.

What is the effect of adding colloids like 22% albumin in blood banking?

It increases the dielectric constant, reducing the zeta potential.

What is the significance of the prozone phenomenon?

It can lead to false negatives in antibody detection due to excess antibodies.

What is the role of centrifugation in antigen-antibody reactions?

It enhances physical contact between antigen and antibody.

What is the most potent antibody in terms of complement activation?

IgG3

What is the difference between true agglutination and rouleaux formation?

True agglutination involves intact clumping, while rouleaux formation is a pseudoagglutination due to antibody excess.

What is the approximate hematocrit (Hct) of whole blood?

Hct is approximately 40%.

What is the storage temperature for whole blood?

1-6 degrees Celsius.

What is the shelf life of whole blood stored in ACD, CPD, or CP2D?

21 days.

What is the shelf life of packed red blood cells stored in CPDA1?

35 days.

What is the storage condition for frozen red blood cells?

Stored at -65 degrees Celsius with less than 1% glycerol for up to 10 years.

What is the maximum hematocrit (Hct) for packed red blood cells?

Hct should be less than or equal to 80%.

What is the storage temperature and duration for washed red blood cells?

Stored at 1-6 degrees Celsius for 24 hours.

What is the pH requirement for platelets?

pH must be greater than or equal to 6.2.

What is the storage temperature and shelf life for platelet concentrates?

Stored at 20-24 degrees Celsius for 5 days.

What is the required fibrinogen level for cryoprecipitate?

Fibrinogen must be at least 150 mg per unit.

What are the donor requirements for allogeneic blood donation?

Requirements include age, weight, pulse rate, blood pressure, temperature, hemoglobin, and hematocrit.

What is the procedure for blood collection?

Use aseptic technique, apply a tourniquet, and use a 16-gauge needle.

What are common adverse effects for blood donors?

Fainting, hyperventilation, citrate toxicity, nausea, and vomiting.

What tests are performed during blood processing?

ABO typing, Rh typing, antibody screen, and serologic tests for various infections.

What is the goal of pretransfusion compatibility testing?

To ensure that the donor's blood will be accepted by the recipient.

What are the possible blood types of children from an O mother and AB father?

Children can be A, B, AB, or O.

What is the significance of the ABO blood group system in transfusion?

It is the most important blood group system with naturally occurring antibodies against absent antigens.

What can cause severe hemolytic transfusion reactions?

Incompatibility in the ABO blood group system.

What is the genotype for blood type A?

AA or AO.

What is the genotype for blood type B?

BB or BO.

What is the genotype for blood type AB?

AB.

What is the genotype for blood type O?

OO.

What are amorph genes?

Genes with no visible product or physical manifestation, such as the absence of A and B or D, H.

What does codominant mean in genetics?

Genes that are both expressed simultaneously, resulting in both gene products being manifested, as seen in blood types AB and MN.

Define phenotype in genetics.

The physical manifestation or product of the genes.

Define genotype in genetics.

The genetic makeup of an organism, usually consisting of pairs of alleles.

What is homozygous?

A condition where genes assume a single form, having two copies of the same allele.

What is heterozygous?

A condition where inherited genes have different forms or alleles.

Where is the Lewis gene located?

On chromosome 19.

What are Lewis antigens?

Antigens manufactured by tissue cells, secreted into body fluids, and adsorbed into RBCs.

What types of Lewis phenotypes exist?

Le(a+b-), Le(a-b+), and Le(a-b-).

What is the nature of Lewis antibodies?

Naturally occurring, IgM type, cold reactive, and not clinically significant.

When do ABO antibodies develop?

Around 3-6 months of age.