Immunology, Autoimmunity and Related Disorders Flashcards by Kershia Mukoro

Hypersensitivity can be defined as?

A normal but exaggerated or uncontrolled immune response to an antigen that can produce inflammation, cell destruction, tissue injury.

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What are the 4 types of hypersensitivity?

Type I - Anapylactic
Type II - Cytotoxic
Type III - Immune Complex
Type IV - T cell dependent

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An allergy refers to?

What condigtion it is related and which Ig is it mediated by?

An altered reaction to external substances
- Related to atopy, that refers to immediate hypersensitivity mediated by IgE antibodies

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Histamine is released by?

Mast cells or basophils

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An allergic reactio to plasma products containing IgG may occur in individuals that are?

IgA - deficient

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Ultarcartarial reations are?

Skin rashes
hives
swelling from mosquito bite
animal hair
allergy testing
dermatitis
exzema

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What are the two types of Anaphylaxis?

Systemic - throat closes, brochioles swell, difficulty swallowing, difficulty breathing, shock, drop in blood pressure, fainting, loss of consiousness, immediate coughing, sneezing, cramps, vomiting, diarrhea, cramps, pain, dizziness, death if untreated.
Local - visible rash, hives, swelling, redness, warmth, pain, itching.

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A Type I allergic reaction can be mediated by what cells?ex: allergic contact dermatitis

T - lymphocytes (regulatory)

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______ can be attracted to the area of activity by chemotactic factors and may release _____ mediators that ____ the effect of ______ mediators

Eosinophils

secondary

limit

primary

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Hypersensitivity Type II - cytotoxic reactions are a consequence of?

IgG or IgM bindind to the surface of cells

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What is the test for Type II?

DAT

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What are the three mechanisms of Type II ?

What are the examples of each mechanism and how they work.

Antibody dependent, complement mediated cytotoxic reactions
- Ex - HTR / HDN
Antibody dependent, cell mediated cytotoxicity
- Goodpastures syndrome. IgG autoAbs bind glycoprotein in the basement mebrane of glomeruli and the lungs, activates complement and triggers inflammatory resonse.
Antireceptor antibodies
- Abs bind to cells and affect their function. Stimulate target organ function wihtout causing organ damage in some cases Wegner’s granulomatosis may lead to tissue damage.

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Type III immune complex reactions are caused by?

Deposistion of immune complexes in blood vessel walls and tissues

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What is an Arthus Reaction?

Repeated exposure leads to sensitization producing an insoluble antigen-Ab complex.

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What are 2 common skin conditions of Type III reactions?

Allergic Vasculitis
Erythema nodosum

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A Type III pulmonary reaction?

Hypersensitivity pneumonitis (farmers lung - reaction to thermophilic actinomycetes found in moldy hay)

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Bathtub refinisher’s lung, Epoxy resin lung, and plastic worker’s lung can be cause by what?

Chemicals
- tolulene diisocyanate
- phthalic anhydride
- timetallic anhydride

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What assays are commonly used for Type III reactions?

Latex aggutination
Nephelometry
Chemiluminescence

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What are Type IV reactions caused by?

Immune activities that differ fom Abs mediated immunity.

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Cell mediated immunity is moderated by the link between what 2 cells?

Between T-lymphcytes and phagocytic cells

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Lymphocytes (T cells) don’t recognise antigens of a microrganism or other living cells by are immunologically active via varios types of direct cell to cell contact and by the soluble factors.

True / False

True

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Type IV delayed-type hypersensitivity (DTH) involves T cells that do what?

Antigen sensitized T cells that stay phagocytized in a marcrophage and are previously encountered by activated T-lymphocytes for a second time.
T cells respond directly or by the release of lymphokines exhibiting contact dermatitis and infection allergies

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Monocloncal gammopathies are classified by?

Production of monoclonal immunoglobulin (Ab)

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MAbs are involved with the supression of?

Uninvolved immunoglobulins and dysfunctional T cell responses.

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MAbs result from the single clone of a lymphiod (B cell) plasma cells producing higher levels of a single class/ type of immunogloulin called? * Monoclonal protien * paraprotein * M Protein * All of the above

All of the above

Monocloncal gammophathies can be benign or malignant? True / False

True

What is the most common plasma cell disorder? How does age affect this disorder?

Premaligant precursor of myeloma, Monoclonal Gammopathy of Undetermined Significance (MGUS) Incidence increases with age

What is Multiple Myeloma?

* Plasma cell neoplasm characterized by the accumulation of malignant plasma cells within the BM micronvironment. * Monocloncal protein in the blood or urine * Assocated organ dysfuction

In multiple myeloma the percentage of plasma cells in the BM can rise to?

90%

What factors may be a cause of multiple myeloma? What environment stimilants may be a cause?

* Radiation or viral causes

What environment stimilants may be a cause of multiple myeloma? * Asbestos * Benzene * industrial toxins * All of the above

All of the above

What is the most common form of dysproteinemia and accounts for 1% of all malignant diseases and 10% of hemaologic malignancies?

Multiple Myeloma

What is the most common form of Multiple Myeloma * IgG Myeloma (52% of patients) * IgM Myeloma (52% of patients) * IgA Myeloma (52% of patients) * IgE Myeloma (52% of patients)

IgG Myeloma (52% of patients)

Most patients with MM die within? Due to?

* 1 - 3 years * Sepis and renal insufficiency

How does MM affect the skeleton and cause bone pain?

90% have broadly disseminated destruction of their skeleton

What is the most consitent feature of MM?

Incessant systhesis of a dysfuntional single monoclonal protein or of immunoglobulin chains of fragments with concurrent supression of the systhesis of normal fuctional Ab.

In 99% of MM patients what i found in urine, serum or both?

M component

Proteinuria is a common occurence in MM, with approaximaty what percentage of patients excreting what protein? What percentage of patients only excrete this protein?

* 50% excreting Bence Jones Protein * 10%

What is an improtant diagnostic marker of MM?

Bence Jones Protein

A common finding in the peripheral smear of patients with MM?

Rouleaux formation due to increases in monoclonal protein production.

A common B cell dissorder characterized by infiltration of lymphoplasmacytic cells in to the bone marrow and prescence of an IgM Monocloncal gammopathy?

Waldenstroms Primary Macroglobulinemia (WM)

The may be a genic cause for WM as 20% of patients are related? True / False

True

WM occurs 10% as frequently as MM? True / False

True

MM if often found in what age individuals with a survival rate of?

60 - 64 years 3 years after diagnosis

The following are initial symptoms of WM? * Weakness * Fatigue * Bleeding from nose and gums * all of the above

All of the above

40% of patients will WM will also develop enlargement of which organs?

* Hepatomegaly * Splenomegaly * Lymphomeglaly

Elevated IgM levels in WM affect eyesight causing?

Blurred vision

Contrary to MM, bone pain in WM is almost non-exisitent? True / False

True

What affects 90% of patients with chronic uncontrolled WM?

Congestive heart failure

Micrscopic apsirate examination in an individual with WM often reveals?

Ragged cytoplasm and stain positive with periodic Acid-Schiff.

Defined as an increase in more than one immunoglobulin and involves serveral clones of plasma cells?

Polyclonal gammopathies

Polyclonal gammopthies consist of one or more heavy chain classes and both light chain class types, as opposed to monocloncal light chain configurations? True / False

True

Polyclonal gammopathies are often seen in? * Chronic infections * Chronic Liver disease (esp. chronic active hepatitis) * Rhematoid connective tissue (autoimmune) disease * Lymphoproliferative disorders * All of the above

* All of the above

The classic model for autoimmune disease is?

SLE

A chronic sytemic rheumatic disorder affecting multiple systems including - joints , connective tissue, collagen vascular system?

Systemic Lupus Erythematosus (SLE)

SLE can occur at any age but is more frequent in?

10 - 15 times more freq in women than men after puberty

What is the survival rate for Lupus?

90% at 10 years after diagnosis

What is a leading cause of death in hopitalized patients suffering from progressive renal disease or CNS disease?

SLE

Immunosupression from steriod treatment can interfere wit host defence against oppoertunistic infections like? M. Tuberculosis H. Capsulatum L. Monocytogenes All of the above

All of the above

What sign/ symptom is seen in 90% of SLE patients? * Fatigue * Weight loss * Joint pain / arthritis * Butterfly rash

Joint pain / arthritis

What sign/ symptom is seen in 40% of SLE patients? * Fatigue * Weight loss * Joint pain / arthritis * Butterfly rash

Butterfly rash (across nose and cheeks)

SLE increases suceptibility to

common and oportunitstic infections

Blood tests for SLE may find (3)?

* Moderate anemia * Lymphocytopenia * Thrombocytopenia

Serologic manifestations of SLE will show (4)?

* High levels of Antinuclear Abs (ANAs) * Immune complexes * Complement level depression * Tissue depositions of immunoglobulins and complement

What is the hallmark autoAb of SLE?

Antinuclear Antibodies

ANA antobodies include: * DNA Histone * Non-histone protein * All of the above

All of the above

A heterogenous group of immunoglobulins (IgM, IgG, and IgA) that react with the whole nucleus or nuclear components such as DNA and nuclear proteins.

ANA

Elevations in Abs to cardiolipin are present in patients in SLE associated with arterial and venous throboses and in those with placental infarcts in early pregnancy with or w/o SLE may be an predictive of?

Risk of throbosis or recurrent spontaneous abortions in early preganancy

This is a progressive inflammatory disease of the joints.

Rhematoid arthritis

Severe cases of R can manifests as this where the hands and feet are severely deforemed.

Polyarthritis

No specific genetic relationship has been eastablished, but there is an increase in incidence in second-degree relatives of people with RA? True / False

False but there is an increase in incidence in **First**-degree relatives of people with RA

People with what haplotype have a higher incidence of RA?

HLA-DR4

What Ig factor is manifested in approx. 70% of adults with RA?

Immunoglobulin M Factor

Rheumatoid factor is associated with which three major immunoglobulin classes? Is this a cause of the disease?

IgM IgG IgA These are the most common No, they are made during the course of the disease

True / False - High titres are associated with severe RH - EX; Rhematic Fever, Lupus, Osteoarthritis

True

RF correlates with? Vasculitis Felty's syndrome Sjorgren's Syndrome All of the above

All of the above

Agglutination tests for RF, such as sensitized sheep cell test and latex agglutination generally detect? * IgA RF * IgG RF * IgM RF * IgE RF

IgM RF

ANA is demonstratable in what percentage on RA patients?

14 - 28%

True / False - in RA, ANA titres are generally higher than in SLE?

False ANA titres are lower in RA than in SLE

Which of the following is NOT true rearding complement levels in patients with RA? * Levels normal except those with vasculitis * Dperessed hemolytic complement levels found in 1/3 patients * Found in patients with very high levels of RF and immune complexes * None, all are true statements

None, all are true statements

Describe MHC? (3) Where are they found? What do they code for? Specifically code for?

* a cluster of genes founf on chromosome 6 at band 21 (6p21) * They code for protiens that have a role in immune recognition. * Encode HLAs, which are the moluclar basis for T cell discrimination of self from non-self

* Proteins found on tisse and blood cells * Found on all nucleated cells * Pivotal in the development of humoral and cellular immunity?

MHC

What is the main fuction of MCH?

* Antigen presentation for T cell recognition * T cell activation only occurs when antihen is combined with MHC molecules

What is second only to ABO antigens in influencing survival or rejection of transplanted organs?

MHC

What MHC class moleculae is found on most nucleated cells?

MHC Class I

These MHC molecules are onlu found in certain cells associated with the immune system, such as monocytes and macropahges?

MHC Class II

How does MHC regulate the specific immune response?

MHC restriction

Can interact with antigens bound to the MHC class II molecules on the surface of antigen presenting ells. They then activate B lymphocytes

Helper T Cells (CD4)

Only interact with antigens bound to the MHC class I molecules, usually on the surface of virally infected cells.

Cytotoxic T cells (CD8)

Graft versus host disease is due to?

Histocompatibility differences between the graft and recipient

GVHD usually arises in which individuals (2)? What organs does GVHD commonly affect?

* Immunocompromised * Common after allogenic BM or hematopoetic cell transplant * Skin, gut, liver

Defined as a delayed immune transfusion reaction due to an immunogenic attack by viable donor lymphocytes contained in the transfused blood component against the transfusion recepient.

Transfusion associated GVHD

How does Transfusion associated GVHD affect the skin, gut and liver? Other reations

* Skin - macropapular rash (starts centrally then moves outwards to extremities) * Gut - Watery diarrhea * Liver - elevated liver function tests * pancytopenia and fever

Occurs between 3 - 30 days after reciept of a non-irradiated blood component leading to profound BM apalasia and a mortality rate of \> 90%?

Transfusion associated GVHD

What is a key prevention menthod for transfusion associated GVHD? What is the dosage used for irradiation? What is the issue with higher dosages?

Irradiating cellular components 2500 - 5000 cGy More effective but more damage to RBCs

What are the two types of immunoassay?

Heterogenous Homogenous

What type of assay is this? * Involve a solid phase (microwell, bead) * Require washing steps to remove unbound antigens or Abs * Have a competitive or non competitive format

Hetrogenous

What type of assay consists of? * Only a liquid phase * Does not require pre-washing * Faster and easier to automate * Have competitive formats

Homogenous

What are the three types of label applied in immunoassays?

* Enzyme Immunoassay * Chemiluminescence * Flourescent substances

What is considered the earliest method for labelling components in immunoassays?

Using antigen coated cells

What are the ideal characteristics of a immunoassay label?

Measurable by several menthods, including visual inspection

What determines that way a lable is detected in an immunoassay?

The properties of a label

What is chemiluminescence? What is this extensively used in?

Light emmision produces during a chemical reation. Automated immunoassay

Which of the following is NOT true regarding chemiluminescence? * Has excellent sensitivity and dynamic range * Requires sample radiation * Non selective excitation and source instability are eliminated * Most chemeluminecent reagents are relatively stable and nontoxic

NOT TRUE - Requires sample radiation **It does not require sample radiation**

Enzyme Linked Immunoassay (ELISA) aka EIA detecs antigens or Abs by?

Producing and enzyme linked colour change

What EIA general approach uses? * Safety * Objective measurement giving numerical results * Provides diagnostic info

Use of nonisotopic levels

What EIA general approach uses? * Detects and quantitates immunologic reactions * uses enzyme labelled Ab or antigen conjugate * Enzyme and corresponding substrate detects the prescence and quauntity of Ab or antigen in patient specimen * In some tissues enzyme labelled Ab can identify antigenic location

Use of catalytic properties of enzymes

To be used for an enzyme immuno assay and enzyme must (3)?

* High degree of stability * Have extreme specificity * Not be present in Ab or antigen being tested

The following are types of EIA for antibody detection? * Noncompetitive EIA * Competitive EIA * Capture EIA * All of the above

All of the above

A spefic antigen is attached to a solid phase, patient serum is added that may have Ab folllowed by adding the enzyme labelled AB. Substrate changes color if Ab is present. Amount of Ab present is proportional to colour change. What type of EIA is this?

Noncompetitive

Uses a solid pahse to with a specific antigen attached. Patient sample potentially containing Ab along with enzyme labelled Ab specific to test Ab are mixed. the amount of color is inversely proportional to the Ab in patient's serum. What type of EIA is this?

Competitive

Designed to detect a specific type of Ab such as IgM, IgG, CMV IgM, rubella IgM, or toxoplasm IgM. What type of EIA is this?

Capture EIA

Chemiluminescent labels are used to detect?

* Proteins * Viruses * Oligonucleotides * Genomic nucleic acids

What are the two formats of chemiluminscent assay?

Competitive and sandwich

* A fixed amount of labelled antigen competes with unalbelled antigen from a patient specimen for a limited number of antibody binding sites. * Amount of light emitted is inversely proportional to the amount of analyte (antigen) measured.

Competitive immunoassay

* Sample antigen binds to an antibody fixed on to a solid phase. * Second Ab labelled with cheniluminescent label, binds to the antigen-Ab complex on the solid phase. * Light emmited is directly proportional to analyte concentration

Sandwhich immunoassay

What are the 5 major groups of chemiluminescent labels?

1. Luminol 2. Acridinium esters 3. peroxyoxalates 4. dioxetanes 5. Tris (2,2'-bipyridyl) rutenium

What chemiluminescent label is highly specific and can be used to label both antibodies and haptens? ## Footnote Luminol Acridinium esters peroxyoxalates dioxetanes Tris (2,2'-bipyridyl) rutenium

Acridinium esters

In the flourescent antibody technique the Ab is labelled with?

Flourescein isothiocynate (FITC)

In fourescent techniques Abs are conjugated to other markers as well as fourecent dyes called?

Colorimetric immunologic probe detection

Flourescent conjugates are used in what popular basic methods?

* Direct immunoflourescent assay (DFA) * Inhibition Immunoflourescent Assay (IIF) * Indirect Immunoflourescent Assay (IFA)

A conjugated AB is used to detect the antigen Ab reactions at a microscopic level. What immunofoureacent assay is this?

DFA

A blocking test where the antigen is exposed to unlabelled Ab and then labelled Ab, washed then examined. Use to confirm FA technique. What immunofoureacent assay is this?

IIA

Used extensively in the detection of autoAbs and antibodies to tissues and cellular antigens. What immunofoureacent assay is this?

IFA

What emerging labelling technique uses semiconductor crystals as flourescent labelling reagents?

Quantum Dots

What emerging labelling technique uses superparamagnetic particles to tag Abs to bind with antigen? What microrganism is this used to detect?

SQUID Listeria Monocytogenes

What emerging labelling technique uses two different latex particles and a chemiluminscent molecule?

Luminescent Oxygen-Channeling Immunoassay

What emerging labelling technique uses tyramide?

Signal Amplification Technology

What emerging labelling technique uses high resolution magnetic recording tech?

Magnetic labelling technology

What emerging labelling technique measures flourescence agter a cetain period of time to exclude background interference?

Time-resolved Flouroimmunoassy

What emerging labelling technique uses flourescent moleculaes to brightly paint genes or chromosomes?

Flourescence in situ hybridization (FISH)

Nepheleometry depends on and measures?

* the light scattering properties of the antigen-Ab complex * The quantity of cloudiness "turbidity" in a solution photometrically.

In Nephelometry the use of what enhances and stabilizes the precipitates?

* PEG * increases particle speed * technique sensitivity by controlling partical size

In immunology nephelometry is used to measure?

* Complement components * Immune complexes * Presence of a variety of Abs

What is the principle of nephelometry?

Formatiom of a macromolecular complex is the fundamental prerequisite for nephelomteric protein quatitation.

What expresses the relation ship betwwen the quantity of antigen and the measuring signal at a constant Ab concentration?

Heidelberger Curve

A fixed time measurement is used in? * Chemiluminescence * Immunoflourescence * Fixed time method * Capture menthod

Fixed time method

Combines fluid dynamics, optics, laser science, high speed computers and flourochrome conjugated MAbs which classifies groups of cells in homogenous mixtures?

Flow cell cytometry

What are the major applications of Flow cell cytometry?

Identification of cells Cell sorting before further analysis

What is the principle of Flow cell cytometry?

* Based on reactions of dyes with the cellular component of interest * Laser activates the dye, flourescence is collected by optical sensors

What is a flourochrome?

An immunologic reagent, a dye that stains a specific component.

An in vitro method that amplifies low levels of specific DNA sequences in a sample for further analysis?

PCR

To use PCR the following are needed EXCEPT? * Sequence must be known * targer 100 - 1000 bp long * Primers 16 - 20 bp * None all are needed

In PCR what acts as the DNA template?

Oligonucleotides

In PCR the primer sequences are complementary to which end of the DNA?

3' ends of sequence to be amplified

The enzymatic process of DNA is carried out in 3 cycles which are?

* DNA Denaturation - seperation of dsDNA though heat * Primer Annealing - oligo primers bind to ssDNA strands * Extension of DNA - DNA polymerase synth. new complementary DNA

Each cycle of PCR does what to the amount of DNA? PCR is repeated for how many cycles?

Doubles 30

The contents of a PCR are typically examined by? What does the above techniqe enable?

Gel electrophoresis Visualization of amplifies gene segments and determination of their specificity

How is additonal product analysis on PCR contents carried out?

Probe hybridization Direct DNA sequencing

What are the important applications of PCR?

* Amplificatiom of DNA * ID target sequence * Syththesis of labelled antisense probe

PCR can lead to the detection of? (4)

* Detect gene mutations early in cancer * ID viral DNA w/ specific cancers * Detection of genetic mutations associated w/ diseases * **Coronary artery disease** associated with mutations of the gene that codes for LDLR (low density lipoprotein receptor)

Uses reverse transcriptase Useful in ID of RNA Viral agents like HIV and Hep. C

RT PCR

Uses numerous primers in a single reaction?

Multiplex PCR

Uses flourescence resonance energy transfer to quantitate DNA sepences. Less suceptible to amplicon contamination

Real-time PCR

Only RNA is target for amplification Used in quantitation and detection of HIV and CMV

Nucleic Acid Sequence-based Amplification

Types of blotting techniques?

Southers Northers Western

What procedural steps are shared with Northern and Southern Blotting? (4)

* Electrophoretic seperation of patient nucleic acid * Transfer of nuclic acid to solid support * Hybridzation with labelled probe of known sequence * Auto-radiographic / colourimetric detection of the bands created by the probe-nucleic acid hybrid

What are the clinical diagnostic applications of Southern blotting?

* Fragile X syndrome * Determination of cloncality in lymphomas of T / B cell origin * Sickle cell anemia * Hemophilia A *

dsDNA is cut by what in Southern Blotting?

Restriction Enzymes

In Southern blotting the resulting dsDNA bound to the radiolable is detected by?

Radiography

What is sperated by electrophoresis in Northern Blotting?

RNA (mRNA)

What is bound to the RNA (mRNA) in Northern blotting?

Complimentary radiolabelled ssDNA fragments

Which blotting technique is not routinely used in clincal molecular diagnostics?

Northern blotting

What are the steps for Western blotting?

Electrophoresis to seperate proteins Transferred to membranes ID through use of labelled Abs for specific protein of interest

What is the application of Western Blotting?

* Detects Abs to specific epitopes of entigen subspecies * Electrophoresis seperates by molecular weight (MW) * Antigen blotted to nitrocellulose reatining elctrophoretic position * react w/ patient specimen results in specific Abs if present bind to each band. * Electrophoresis of known MW allows for determination of each antigenic bands MW to which Abs produced * Abs are then detected by EIA the characterize specificity.

Immunology, Autoimmunity and Related Disorders Flashcards

(165 cards)