Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y2 Immunological Disorders > Week 7 > Flashcards

Week 7 Flashcards

1
Q

What are the 4 mechanisms for immune effector strategies against pathogens?

A

Complement
Neutrophils
B cells
T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens if one of the 4 mechanisms against pathogens has defects?

A

The host can become immunodeficient and susceptible to opportunistic, life threatening infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the usual causes of primary immunodeficiency?

A

Genetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How long do primary immunodeficiencies last?

A

They will last for life and require constant treatment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the usual causes of secondary immunodeficiency?

A

External influences such as; viral infections, chronic infections, malignancy, age, drugs, antibody therapy, plasmapheresis, radiation, nutrition, chronic renal disease, splenectomy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How long do secondary immunodeficiencies last?

A

They will go away if treated correctly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name some of the warning signs of primary immunodeficient.

A
  • Eight new infections in 12 months or 2 sinus infections or episodes of pneumonia within 12 months.
  • Two months of antibiotics with little effect or need for IV antibiotics to clear infections.
  • Episodes of opportunistic infection.
  • Complication associated with live vaccines.
  • Prolonged or recurrent diarrhoea.
  • Family history of PID.
  • Absence of immunological tissues.
  • Unexplained early infant deaths.
  • Auto-immune diseases.
  • Difficult to treat obstructive lung disease.
  • Severe eczema and dermatitis
  • Eosinophilia that is unexplained.
  • Failure to thrive in children.
  • Delayed separation of umbilical cord after 4 weeks in children.
  • Recurrent deep skin or organ abscesses.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name some medical treatments which may be the cause of secondary immunodeficiencies.

A

Bone marrow transplantation.

Biological therapy.

Chemotherapy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What methods are useful first lines of investigation in terms of immunodeficiencies?

A

Full blood count.

Immunoglobulin levels in blood.

Complement levels in blood tested.

Odd response to immunisation via a vaccine.

Lymphocyte population analysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What method is used to measure immunoglobulin levels in the blood?

A

Nephelometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does Nephelometry measure the quantity of immunoglobulins in a patients blood?

A

The addition of constant amounts of highly purified and optically clear specific anti-Ig antibodies to the patients serum.

If the antiserum binds to immunoglobulin, it will turn cloudy.

The more cloudy the sample, the more immunoglobulin present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the rabidity of a mixture?

A

Its clarity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 3 complement pathways?

A

Classical
MB-Lectin
Alternative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Outline what happens in the classical complement pathway.

A

Triggered by antigen-antibody complexes binding to C1. This leads to the generation of C3b, which can attach to the surface of microbial pathogens, an opsonise them and to C3a which leads to activation of mast cells and the release of histamine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is complement activity measured?

A

Gel contained sheep erythrocyte coated with rabbit anti-sheep erythrocyte antibody.

Complement C1 is fixed by the immune complex.

Lysis of the sheep RBCs causes a zone of clarity in the gel.

The size of the zone of lysis is dependent on the original complement activity in the serum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Outline what happens in the MB-Lectin complement pathway.

A

Factors B, D, H and I interact with C3b to form C3 converts and activate C4. This is promoted by the presence of bacterial and fungal cell walls, but is inhibited by the surface of normal mammalian cell walls.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What could you use to test the ability of a person to productive a functional antibody in response to an infection?

A

Protein vaccines

Tetanus toxoid

Polysaccharide vaccines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In which people can polysaccharide vaccines not be used to test for functional immune responses?

A

Children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the unique analysis properties of flow cytometry?

A

Looks at populations of cells on a cell by cell basis.

Rapid.

Multiple parameter measurements on a single cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 3 system components of flow cytometry?

A

Fluidics system

Optics system

Electronics system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the fluidics system of Flow cytometry?

A

This transports cells in a stream of buffer. The diameter of this stream allows single cell analysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the optics system of flow cytomtry?

A

Laser to illuminate particles in sample stream and optical filters to direct the resulting light signals to detectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the electronics system of flow cytometry?

A

Converts detected light signals into electrical systems that can be processed by a computer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does CD mean in terms of lymphocytes?

A

Clusters of differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In terms of immunodeficiency, how does identifying leucocytes help prognosis?

A

Helps identify the cell types and stages of differentiation evolved in the specific immunodeficiency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How are lymphocyte subpopulations defined?

A

By their expression of CD numbers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are SCIDs?

A

Severe immunocompromisations which can be fatal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does SCID stand for?

A

Severse combined immunodeficiencies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

If patients are detected to have SCID, what should happen?

A

This should be immediately reported to a consultant immunologist ant the patient will be transferred to a national centre for barrier nursing and preparation for HSCT.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is HSCT?

A

Haematapoetic stem cell transplantation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is barrier nursing?

A

When a patient is kept in a bay and extra precautions are implemented to prevent the spread of a germ.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is immunophenotyping used for in terms of immunological disorders?

A

To detect the presence and absence of white blood cell antigens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the advantages of immunophenotyping in terms of immunological disorders?

A

Rapid testing

Requires small samples only

Can analyse whole blood

Can test for different cell phenotypes

Can obtain a lot of information

34
Q

What are the disadvantages of immunophenotyping in terms of immunological disorders?

A

Fresh sample required.

Rarely sufficient results for diagnosis.

Issues can occur due to different antibody specificities, mutations may be functional rather than deletion and mutations may be in part of the molecule undetected by the antibody.

35
Q

How do T cell functioning tests work?

A

They mimic in-vivo T cell stimulation;

T cells bind to antigen presenting cells via MHC molecules. Adhesion molecules binding are important to strengthen these interactions.

The DNA generated is measured to estimate proliferation which then indicates the level of T cell activation.

36
Q

What are the 3 signals required for T cell activation?

A
  1. T cell recognises its antigen on an antigen presenting cell in MHC. CD4/8 binds to the antigen presenting cell.
  2. CD28 on the T cell binds to CD80 on the antigen presenting cell.
  3. Cytokines provide the third signal necessary for full T cell activation and differentiate between Th1/ Th2 and Th17. This allows full T cell activation.
37
Q

What happens if the T cell only recognises the first signal ?

A

The cell becomes anergic.

38
Q

What is a Th cell?

A

A helper T cell

39
Q

In proliferation assays, what cell type are isolated?

A

Peripheral blood mononuclear cells are isolated.

40
Q

In proliferation assays, what type of well are PBMC cells isolated into?

A

A 96 tissue culture plate.

41
Q

What is the aim of a proliferation assay?

A

To isolated PBMC’s.

42
Q

What are PBMC’s?

A

Peripheral blood mononuclear cells

43
Q

What happens if the centrifuging step in a proliferation assay isn’t carried out?

A

All of the cells would fall to the bottom of the wells and the peripheral blood mononuclear cells wouldn’t be isolated.

44
Q

After being centrifuged, what happens to PBMC’s in a proliferation assay?

A

They can be pipetted off from the rest of the solution and washed with a buffer. Their cell density is found.

45
Q

In a proliferation assay, what measurement is used to find the quantity of PBMCs present?

A

Cell density

46
Q

After a proliferation assay has been carried out and cell density has been measured, what is done with the PBMC’s?

A

They are plated with patient stimulants for 3-6 days. In the final 8-16 hours, 3H-thymidine is added. If the cells are making DNA, this thymidine will be incorported into their DNA.

47
Q

How does thymidine being incorporated into PBMC cells indicate that the cells are making DNA?

A

Thymidine contains tritium. Tritium will then act as a marker for proliferation and indicate that the PBMC cells are making DNA.

48
Q

What happens after PBMC cells are discovered to be making DNA in a proliferation assay?

A

The cells are harvested onto filter mats and individual wells are placed within a scintillation cocktail and put on a beta counter. This assesses the amount of tritium isotope in each well.

49
Q

How are the final results of a proliferation essay expressed?

A

CPM or Stim Index.

50
Q

What are the issue with proliferation assays?

A

The use of a radioactive isotope is necessary and so exposure to radiation occurs (although this is very low with tritium).

Disposal of radioactive waste has a financial and environmental cost.

The assay doesn’t indicate which cells are proliferating.

Only measures proliferation at the en of an assay who proliferation would be likely to be slower anyway.

51
Q

Does a proliferation assay indicate which cells exactly are proliferating?

A

No

52
Q

What is the issue with proliferation assays only measuring proliferation levels at the end of the assay?

A

Proliferation would usually be lower at this time anyway.

53
Q

Name some possible methods to purify lymphocyte populations and explain briefly how each one works.

A
  • Pulling out chosen populations of cells by binding them to antibody-coated plastic surfaces.
  • Removing unwanted cells with specific antibody and complement. This works by killing chosen cell types but leaves the cells that you still want.
  • PBMCs are incubated with an antibody magnetic bead. They are then washed and put through a column which has a magnet attached. B cells will bind to the column whilst other cells will pass through the column and be separated.
  • Fluorescence-activated cell sorting.
54
Q

In what stage of the cell cycle do lymphocytes usually exist in?

A

G0

55
Q

What indices the entry of lymphocytes into G1 of the cell cycle?

A

Polyclonal mitogens

56
Q

What are mitogens?

A

Substances that stimulate mitosis.

57
Q

What is a flow based proliferation assay used to measure?

A

Cell division

58
Q

Outline how flow based proliferation assays work.

A

CFSE passively diffuses into cells. It is non-fluorescent until the acetate groups are removed by intracellular esterase’s to form a highly fluorescent ester. The relative fluorescence of each cell will half with each cell division.

59
Q

What is intracellular protein staining used for?

A

To examine intracellular protein expression.

60
Q

Outline the process of intracellular protein staining.

A
  1. Activated T cells are treated with an inhibitor which blocks protein export, allowing cytokines to accumulate within the endoplasmic reticulum.
  2. The cell is fixed and permeabilised with mild detergents.
  3. Cytokine-specific antibodies penetrate the cell to bind the intracellular cytokine molecules.
61
Q

In intracellular cytokine staining, what is used to stimulate PBMCs?

A

Nothing
PHA
PHA/lonomycin.

62
Q

What is Foxp3?

A

A transcription factor that is highly important in the correct functioning of regulatory T cells.

63
Q

What is the main function of Foxp3?

A

To prevent activation of the immune system where it is not required.

64
Q

Where are mobile leukocytes present?

A

Peripheral blood

65
Q

Describe the nuclei of neutrophils

A

Multi-lobed

66
Q

Do neutrophils have a short to long half life?

A

Short

67
Q

Name some of the neutrophil activities.

A

Chemotaxis

Target recognition and attachment

Phagocytosis

Fusion of phagosome to lysosome

Activation / deployment of bactericidal mechanisms

68
Q

What is chronic granulomatous disease?

A

Recurrent life threatening bacterial and fungal infections which are caused by a defect in a phagocytic NADPH oxidase function.

69
Q

What are the different possible forms of CGD?

A

X linked and autosomal forms

70
Q

What does CGD stand for?

A

Chronic Granulomatous Disease

71
Q

What kits are used to treat CGD?

A

Orpegen kits and NFT methodology

72
Q

Outline the NFT methodology used to treat CGD?

A

Incubate blood with E.Coli or PMA buffer.

Upon oxidation, the non-fluorescent substrate becomes fluorescent.

Fluorescence is directly related to activity of respiratory burst.

73
Q

What is an NBT test used for?

A

A standard test for Neutrophil function.

74
Q

How does an NBT assay work?

A

Neutrophils are incubated with an activator of a respiratory burst in the present of a soluble yellow dye.

Superoxide radicals reduce the NBT to insoluble blue formazan.

Number of blue cells are counter.

75
Q

What does NBT stand for?

A

Nitroblue Tetrazolium

76
Q

What are the issues with NBT assays?

A

Time intensive

Subjective

Prone to errors

Don’t always identify autosomal recessive CGD.

77
Q

What type of disorder is leukocyte adhesion defect 1?

A

Autosomal recessive disorder.

78
Q

What characterises autosomal recessive disorder?

A

Recurrent bacterial infections

Impared pus formation and wound healing.

Defects in initiation of respiratory bursts to particulate but not soluble stimuli.

Defective chemotaxis and phagocytosis.

79
Q

What is often the first symptom of leukocyte adhesion deficit 1?

A

Delayed umbilical cord separation.

80
Q

What causes leukocyte defect 1?

A

Mutation in the CD18 gene.

Y2 Immunological Disorders (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions