Blood bank questions.

What does C5a specifically do?

chemotactic; attracts leukocytes from peripheral blood to the site

Weiner Theory

-1 locus, 1 gene -Rh-Hr -Useful to describe phenotypes

Characteristics of IgG

-2 gamma heavy chains, two light chains -Monomer Divalent -Inefficient in direct agglutination -2 IgG's needed to activate C' -Four subclasses

What is Extravascular hemolysis?

-Consumption of antibodyand/ or C3b-bound red cells by phagocytes -DHTR

Characteristics of IgE

-Exists as monomer bound to basophils or mast cells -Binding of antigen triggers release of histamine (allergic reactions). -Involved in hypersensitivity - anaphylaxis, parasitic infections

Characteristics of IgA

-Predominant in secretions -First line of defense - prevents foreign agents from entering body -Does not bind complement by classical pathway, but can activate alternate pathway

How is RNA different from DNA?

-RNA usually exists as a single strand -The sugar ribose is substituted for deoxyribose The base uracil exists only in RNA

What percentage of the group A population are type A2?

20%

Rh antibodies react best at what temperature?

37

Approximately what percentage of group A individuals could be further classified as subgroup A1?

80%

The frequency of the D-positive phenotype in the population is?

85%

The Rh system was first recognized in the case report of:

A hemolytic transfusion reaction

A person whose red cell type as M+ N- with antisera would be...?

A homozygote.

What ABO phenotype would agglutinate in the presence of anti-A produced by group B individual?

A only

The weak D test detects:

A weak D antigen

What is the nitrogen base make up of DNA?

Adenine, cytosine, guanine, thymine

What property of antibodies is NOT dependent on the structure of the heavy chain constant region?

Affinity for antigen

What is responsible for the activation of the classic pathway of complement?

Antibody bound to antigen An antigen-antibody complex activates the classical complement cascade, whereas bacterial membranes activate the alternative pathway.

In a serologic test, the term postzone is also known as:

Antigen excess

T lymphocytes functions:

Attack intracellular pathogens Cellular immunity

What is associated with the B-cell response to antigens.

B cells produce antibody, a humoral response.

What cell is involved in the production of antibody?

B cells.

Opsonization is a term to describe what process?

Binding to cells or antigens

What is known as the "recognition unit" in the classical complement pathway?

C1q

What MHC classes are found on antigen presenting cells?

Class II

What is the structure of an Antibody (immunoglobulin)?

Composed of four polypeptide chains joined by disulfide bonds 2 heavy chains, 2 light chains Light chains - kappa, lambda Heavy chain determines class

What portion of the antibody molecule imparts the antibodys unique class function?

Constant region of the heavy chain

What portion of the antibody molecule that imparts the antibody's unique class function.

Constant region of the heavy chain

What is the substance that regulates the activity of other cells by binding to specific receptors.

Cytokines Cytokines are proteins secreted by cells that regulate the activity of other cells by binding to specific receptors.

When is G present?

D or C

How would a donor who tested negative with anti-D reagent in the immediate spin test but positive at antihuman globulin with anti-D reagent be labeled?

D-positive

what haplotype is Cw most associated with?

DCe

What is the most common Rh phenotype in African Americans?

Dce/dce

Part of the antigen that the immunoglobulin binds to

Epitope

What is the potential effect in a tube agglutination test if a red cell suspension with a concentration greater than 5% is used?

False negatives Antigen excess is termed postzone and will lessen the reaction, causing a false negative.

Meiosis is necessary to:

Generate new DNA sequences in daughter cells

What best describes mitosis?

Genetic material is duplicated, equally divided between two daughter cells.

What ABH substances would be found in the saliva of a group B secretor?

H and B

The linked HLA genes on each chromosomes are inherited as a?

Haplotype

Which portion of the immunoglobulin molecule contains complement binding sites?

Heavy chain constant region

Variable region of an immunoglobulin

Idiotype

Isotype

Ig class; determined by the heavy chains

Found in secretions, such as breast milk

IgA

Associated with allergic reactions and mast cell activation

IgE

Has the highest serum concentration

IgG

Most Rh system antibodies are of which immunoglobulin class?

IgG

What immunoglobulin is produced in the secondary immune response?

IgG

Type O people produce

IgG class abs -anti-A,B

Associated with immediate-spin in vitro reactions

IgM

Has the highest number of antigen binding sites

IgM

The major immunoglobulin classes of anti-B in a group A individual is?

IgM

Type A and B people generally produce

IgM class ABO antibodies

The type of immunoglobulins determined by the heavy chain

Isotype

Crossing over occurs during:

Meiosis

The immunodominant sugar responsible for blood group A specificity is?

N-acetyl-D-galactosamine

You are working on a specimen in the lab that you believe is Bombay phenotype. What reaction would you expect?

No agglutination with Ulex europaeus

Translation of proteins from RNA takes place:

On the ribosomes in the cytoplasm of the cell

In a pedigree, the "index case" is another name for:

Propositus

What type of molecules are Rh antigens?

Proteins

A patient phenotypes as D+C+E+c+e-, the most likely genotype is?

R2R2

What phenotype has the strongest D antigen expression?

R2R2

B lymphocytes functions:

Recognize and clear extracellular material Manufacture antibody that specifically recognizes antigen Humoral immunity

What do Rh-null cells lack?

Rh antigens

Anti-LW will not react to which of the following?

Rh-null RBC's

DNA is replicated:

Semiconservatively from DNA

Idiotype

Specific to the antigen stimulating the response. Example: Complementary determining regions of antibodies are unique.

Transcription is:

Synthesis of RNA using DNA as a template

What cell is involved in antigen recognition following phagocytosis?

T lymphocytes

When a recessive trait is expressed, it means that:

Two genes carrying the trait were present

What is the region of the antibody molecule responsible for imparting unique antibody specificity.

Variable region

What does C3b specifically do?

an opsonin, promoting the phagocytosis of the cell to which it is attached

An antigen that originates from the individual is termed:

autologous, cell or tissues from self

Tippitt Model

-2 loci, 2 genes linked -RHD, RHCE -Presently considered to be correct

Fisher-Race Theory

-3 loci, 3 genes linked -DCE/dce -Useful to describe ags & abs

Characteristics of IgD

-Exists as monomer on unstimulated, resting B lymphocytes -No blood group antibodies known to be IgD

Characteristics of IgM

-First antibody produced in immune response -Five basic Ig molecules held together with a joining (J) chain -Found on surface of unstimulated, resting B lymphocytes -Pentamer -10 potential ag-binding sites -Direct agglutinate -Efficient in complement (C') activation

What is Intravascular hemolysis?

-Red cells lysed before opsonization can induce phagocytosis -AHTR -Typically caused by IgM

When is f present?

-ce

The major histocompatibility complex is located on chromosome 6 and is important in all the following immune functions:

-recognition of non-self. -graft rejection. -coordination of cellular and humoral immunity.

What ABO blood group contains the least amount of H substance?

A1B

Which cells agglutinate most strongly with Ulex europaeus lectin?

A2 and O

RNA is processed:

After RNA is copied from DNA template

According to Landsteiners rule, what ABO antibody will be detected in a group B individuals serum?

Anti-A

What is known as the "membrane attack complex" in the classical complement pathway?

C5b, C6, C7, C8, C9

Which class of HLA antigens would be typed when matching patient and donors for platelet transfusion?

Class I only Class I antigens are found on the surface of platelets; however, class II are not.

What MHC class encodes the complement components?

Class III

Which complement pathway is activated by the formation of antigen-antibody complexes?

Classical

T cytotoxic (TC)

Clear viral infected, tumor, and foreign tissue graft cells CD8

How are Rh antigens inherited?

Codominant alleles

What term describes that unique confirmation of the antigen that allows recognition by a corresponding antibody?

Epitope

Imparts flexibility to the immunoglobulin molecule

Hinge region

Rh antibodies are primarily of which immunoglobulin class?

IgG

What immunoglobulin class is capable of crossing the placenta?

IgG

Associated with intravascular cell destruction

IgM

Efficient in activation of the complement cascade

IgM

What immunoglobulin is produced in the primary immune response?

IgM

Which immunoglobulin is most efficient at binding complement?

IgM

What immunoglobulin class reacts best at room temperature at immediate spin?

IgM IgM is a large immunoglobulin with multiple binding sites that is detectable at room temperature and the immediate spin phase.

In order to enhance the reaction of an antibody in vitro, it may be necessary to adjust:

Increase the incubation time in the incubator Increasing incubation time is effective in increasing antibody reactions; however, optimal temperatures, centrifugation, and antigen concentrations are normally not altered when performing routine transfusion service testing.

Cells carrying a weak-D antigen require the use of what test to demonstrate its presence?

Indirect antiglobulin test

One of the two types of light chains

Kappa

Molecules that promote the update of bacteria for phagocytosis are:

Opsonins

What causes an individual to type RhD positive yet possess anti-D?

Partial D

Allotype

Parts of the antibody that are common to a host. Example: IgG heavy chain allotype

What is the role of the macrophage during an antibody response?

Process antigen and present it

T helper (TH)

Recognize and interact with antigen Produce cytokines CD4

Cytokines Functions:

Regulate the intensity and duration of the immune response Stimulate or inhibit activation and proliferation of various cells Regulate inflammation

What portion of the antibody molecule binds to receptors on macrophages and assists in the removal of antibody bound to red cells?

The Fc portion of the antibody binds to the macrophage, which then carries the antigen-antibody complex to the spleen for removal.

Exon refers to:

The coding region of a gene

When a male possesses a phenotypic trait that he passes to all his daughters and none of his sons, the trait is said to be:

X-linked dominant

When a female possesses a phenotypic trait that she passes to all of her sons and none to her daughters, the trait is said to be:

X-linked recessive

What are C3a and C5a?

anaphylatoxins important in the inflammatory response - cause the release of histamines from basophils and mast cells

In a serologic test, the term prozone is also known as:

antibody excess, often leading to a false-negative reaction.

A poor response to platelet transfusion that can be caused by antibodies to human leukocyte antigens is known as:

refractoriness, Blood components that contain leukocytes can increase the immune response to human leukocyte antigens, which may decrease the effectiveness of platelet transfusion.

Extravascular destruction of blood cells occurs in the:

spleen Extravascular destruction of blood cells is initiated by macrophage interaction with IgG molecules attached to red cells that transport the red cells to the spleen for clearance.