Immunology

Classical

Which complement cascade? -Activated by immune complexes (IgG, IgM) -Bind in numerical order except at the beginning (C1, C4, C2, C3, etc.) - Usually "a" fragments go into plasma, "b" fragments attach to cell (exception: C2a & C2b)

HBsAg

Which is the first marker (antigen or antibody) which will become positive after exposure to Hepatitis B?

IFA testing

Which laboratory technique is the gold standard for diagnosis of Rocky Mountain spotted fever?

Western Blot

Which method of testing is used for HIV?

ELISA

Which method of testing is used for Hepatitis A antigens in stool?

ELISA

Which method of testing is used for Hepatitis B surface antigen (HBsAg)?

Recombinant Immunoblot (RIBA)

Which method of testing is used for Hepatitis C?

Slide-based immunofluorescent assay (IFA)

Which method remains the "gold standard" for ANA detection?

ELISA

Which testing method is used for IgE and IgE to specific antigens?

Type II (antibody dependent cytotoxicity)

Which type of hypersensitivity reaction? Antibody attaches to cell bearing corresponding antigen, causing cell death Examples: transfusion reaction, autoimmune hemolytic anemia (AIHA), Hashimoto's thyroiditis, Goodpasture's disease

Type III (immune complex)

Which type of hypersensitivity reaction? Formation of large immune complexes not cleared by Mononuclear phagocytic system Examples: Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and serum sickness

Type 1 (anaphylactic, immediate)

Which type of hypersensitivity reaction? IgE mediated (antigen binds to IgE-sensitized Mast Cell and histamine is released) Examples: bee sting, hay fever, asthma

Type IV (delayed)

Which type of hypersensitivity reaction? Sensitized T cells release interleukins; monocyte and lymphocyte infiltration; >12 hours to develop Examples: contact dermatitis (poison ivy, chemicals), TB, Leprosy, Graft vs. Host disease (GVHD)

Flow cytometry ELISA Immunofluoresence

What methods can be used to differentiate T cells and B cells by detecting cell surface markers (CD markers)?

Heavy chains

What section of an immunoglobulin molecule is responsible for the differences between immunoglobulin classes?

HBsAg, HBeAg, anti-HBc IgM

What three hepatitis B virus (HBV) early markers are detectable in serum during the first two months after infection?

During nucleic acid amplification

When are data collected in a real-time PCR procedure?

B lymphocyte

Which cell is responsible for the humoral immune response?

Alternative

Which complement cascade? -Activated by Lipopolysaccharides, Polysaccharides -Involves C3 at 2 points in Cascade -Involves Factors B & D and Control Factors H & I

Enzyme Immunoassay (EIA/ELISA)

-"sandwich technique"- monoclonal or polyclonal antibody adsorbed on solid surface (bead or microtiter well) -add patient serum; if antigen is present in serum, it binds to antibody-coated bead or well -add excess enzyme-labeled antibody (antibody conjugate); forms antigen-antibody-labeled antibody "sandwich" (antibody in conjugate is directed against another epitope of antigen being assayed) -add enzyme substrate, incubate and read absorbance ***washing required between each step. Improper washing leads to false positive results. -absorbance is directly proportional to antigen concentration

IgE

-allergy -type I hypersensitivity -involved in release of histamines from mast cells

IgG ***crosses placenta

-greatest concentration in serum -4 subclasses -activates complement (except for IgG4) -75% of total antibody concentration

IgM

-largest antibody -fixes complement best (multiple binding sites) -prominent in early immune response (indicates acute infection) -5-10% of total antibody concentration

IgA

-predominant antibody I'm body secretions (tears, saliva, nasal mucosal) -serum IgA (monomer) & secretory IgA (dimer) -primary defense against local infections at mucosal surface -two subclasses

IgD

-unknown function -present on B cell surface

radioimmunoassay (RIA)

-very sensitive and specific -patient antigen and labeled antigen are incubated with known amount of specific antibody (unlabeled and labeled antigen compete for binding with antibody) -wash to remove unbound antigen -radioactivity counted on a gamma counter; compare to standard curve Results: -the lower the radioactive count, the higher the concentration of unlabeled antigen (patient) Examples: RIST and RAST

polymerase chain reaction

1. Denaturation (95 degrees Celsius)- separation of target dsDNA through 2. Primer annealing at 50-60 degrees Celsius- hybridize the primers to the single-stranded template 3. Extension (72 degrees Celsius)- polymerize the primer into full-length gene of interest 4. Each cycle doubles amount of DNA

Electrophoresis

A detection method where movement in a gel matrix is caused by an electrical field.

1:2

AIDS patient: Inverse T helper to T regulator ratio? (CD4+) (CD8+)

Oncogenes

Abnormal genes that cause the continuous cell division and uncontrolled cell growth characteristic of cancer.

Direct bacterial agglutination

Agglutination of host antibody to antigenic determinants on a bacterial agent is the principle of:

Hemagglutination

Agglutination resulting from physical attachment of antibody molecules to antigens on an erythrocyte membrane is called:

Free light chains (FLCs)

Are incorporated into immunoglobulin molecules during B-lymphocyte development and expressed initially on the surface of immature B lymphocytes. In normal individuals, serum FLCs are rapidly cleared and metabolized by the kidneys depending on their molecular size.

Hypersensitivity Type I

Association of eosinophils and IgE is found in which Hypersensitivity type?

5-15%

B cells are what % of total circulating lymphoid cells?

Nephelometry

Based on the principle of turbidity resulting from specific antigen-coated latex particles agglutinated by corresponding antibody. ***Used to measure complement components, immune complexes, and the presence of a variety of antibodies.

Molecules that present antigen to CD4+ T cells

Class II Major Histocompatibility Complex genes encode for:

Fc portion

Section of an immunoglobulin molecule that has a constant amino acid sequence that defines the class and subclass of each antibody. Is responsible for the biological activity of the antibody, including activating the complement pathway and binding to natural killer cells.

Class III MHC genes

Complement molecules are encoded by:

Class III MHC genes

Cytokine molecules are encoded by:

High Complexity

Simple repeating units, do not make a good immunogens are:

Waldenstrom's disease

Immunoglobulin M (IgM) is the characteristically overproduced gene product found in:

First trimester

In what trimester of pregnancy is there the greatest risk for the manifestation of complications in maternal rubella infection?

HLA-A,B,C

MCH I codes for:

HLA-DR, DQ, DP

MCH II codes for:

Complement & cytokines

MCH III codes for:

Radioallergosorbent test (RAST)

Measures IgE to specific allergens

Radioimmunosorbent test (RIST)

Measures total IgE

Radioactivity

Method that uses a scintillation counter to detect decay.

Fluorescence

Method used to detect where molecules emit light at a longer wavelength when excited at a shorter wavelength and can be stained as well as labeled.

Large size molecule

Molecular weight of at least 10 KDa is a:

Class I MHC genes

Molecules that present antigen to CD8+ T cells are encoded by:

Proto-oncogenes

Normal genes that induce DNA synthesis, promote cell division, and inhibit cell death:

tumor suppressor genes

Normal genes that inhibit cell division.

Mismatch repair genes

Normal genes that play a role in the repair of errors that can occur during DNA replication.

Proto-oncogenes

Normal genes that promote cell growth and division. ***Mutations in these can convert them into oncogenes.

5-15%

Null cells (NK) are what % of total circulating lymphoid cells?

Diffusion to identify proteins

Precipitation of immune-related proteins in agarose gel relies on the principle of:

Null cells (NK) (K)

Primary immune protection of which lymphocyte? -natural killer cells: cytotoxic without MHC restriction -killer cells: antibody dependent cellular cytotoxicity (ADCC) Important in killing virus infected cells and tumor cells.

B cells

Primary immune protection of which lymphocyte? Antibodies neutralize toxins, activate complement, and act as opsonins.

T cell

Primary immune protection of which lymphocyte? Immune response against viral infections and tumors. Important in delayed hypersensitivity reactions.

Agglutination

Principle: -particulate antigen + antibody -lattice formation (antigen binds with Fab sites of two antibodies forming bridges between antigens) which produces clumping Examples: -direct agglutination (blood bank) -passive hemagglutination (antigen reagent produced by treating RBCs with tannic acid to allow adsorption of protein antigens) -passive latex agglutination (antigen in reagent is attached to latex particle)

Precipitation

Principle: -soluble antigen + antibody (in proper proportions) -lattice formation (antigen binds with Fab sites of two antibodies) which produces visible precipitate: Examples: -double diffusion (Ouchterlony) -single diffusion (radial immunodiffusion) -immunoelectrophoresis -immunofixation

Chemical composition

Proteins and polysaccharides are better than carbohydrates lipids and nucleic acids

C7

Reynaud's phenomenon is associated with a deficiency/dysfunction of the complement fraction:

Light chains

Small chains that are common to all immunoglobulin classes. There are two subtypes: Kappa and lambda, which have different amino acid sequences and are antigenically different.

80%

T cells are what % of total circulating lymphoid cells?

Nuclear antigen

The antibody most frequently present in systemic lupus erythematosus (SLE) patients is directed against:

Chemiluminescence

The detection method that releases light energy as the product of a chemical reaction.

Treg

The lymphocyte subtype that controls autoimmunity in the peripheral blood is:

Foreignness

The more different from the host, the more immunogenic

Targeted tuberculin testing

The purified protein derivative (PPD) test is also known as:

Fab

The section of an immunoglobulin molecule that is the antigen-specific region. It has two light chains and portions of two heavy chains. It is a variable region that has two antigen- combining sites at N-terminal ends. Stands for fragment antigen binding and indicates the fragment after enzyme, papain, cleavage.

Type IV cell mediated hypersensitivity (T cell dependent)

The type of sensitivity reaction associated with macrophage activation, cytokine-mediated inflammation is:

CD19+ CD20+ CD21+

What are the surface markers for B cells?

CD16+ CD56+

What are the surface markers for Null Cells (NK)?

CD2+: rosette with SRBCs CD3+: associated with TCR CD4+: T helper cell CD8+: T cytotoxic/regulatory cells

What are the surface markers for T cells?

Skin tests, RIST, RAST

What are the tests for allergy?

1. Activates phagocytes (chemotaxis) 2. Lyses target cell (foreign organism) 3. Opsonization- enhances phagocytic binding by coating foreign organism and attaching to complement receptors on neutrophils and monocytes

What are the three ways complement functions in order to control inflammation?

Bind to protein

What can be done to make a hapten behave like an antigen?

Calcium and magnesium

What do the cascades (pathways) of complement require?

Release cytokines Become memory cell Interact with B cells

What is the T cell CD4's function?

Become cytotoxic Interact with B cells

What is the T cell CD8's function?

(Patient's total lymph count) X (% of T or B cells)

What is the formula to calculate T and B cell ratios?

Evolve into plasma cells which secrete antibody Become memory cell

What is the function of B cells?

Important in killing virus infected cells and tumor cells

What is the function of Null cells (NK)?

8:1

What is the normal T cell to B cell ratio?

2:1

What is the normal T helper to T regulatory ratio?

2:1 ***A kappa/lambda ratio outside of this range is an indication of a monoclonal gammopathy such as multiple myeloma.

What is the normal ratio of B cells producing kappa chains versus those producing lambda chains?

Fusion of antibody specific lymphocyte and myeloma cell

What is the process of monoclonal antibody production?

surface immunoglobulin (IgD or IgM) Complement receptors

What is the surface receptor for B cells?

No TCR No surface immunoglobulin

What is the surface receptor for Null cells (NK)?

T cell receptor (TCR-1 or TCR-2)

What is the surface receptor for T cells?

Humoral

What kind of adaptive immunity? -B cell (plasma cell)/antibody -defense against bacterial infections (extracellular organisms) -Hypersensitivity Type I (immediate) -Hypersensitivity Type II (ADCC) -Hypersensitivity Type III (Immune Complex)

Cellular

What kind of adaptive immunity? -T cell/ Lymphokines -Primary defense against viral/fungal infections (intracellular organisms) -hypersensitivity type IV (delayed)- example: transplant rejection

Active

What kind of immunity? -individual produces antibody -follows immunization or infection -memory (lasting)

Adaptive (acquired)

What kind of immunity? -specific -memory -examples: T cells (cytokines) and B cells (antibodies)

Passive

What kind of immunity? -antibody transferred to individual (example: gamma globulin injections, placenta transfer) -no memory (temporary)

Natural (innate)

What kind of immunity? -non-specific -no memory -examples: exogenous (skin), endogenous (stomach acid), phagocytosis (PMNs), Natural Killer Cells (NK)