Brainscape's Knowledge GenomeTM

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


See full index

2.1 Molecular Immunology > Sara- Primary Immunodeficiency > Flashcards

Sara- Primary Immunodeficiency Flashcards

1
Q

What cause primary immunodeficiencies?

A

Inherited defects in genes for components of the immune system

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

What are primary immunodeficiencies

A

Diseases usually revealed in early childhood due to enhanced susceptibility to infection

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

What are secondary immunodeficiencies?
(2)

A

Diseases caused by environmental factors

e.g. caused by infections or immunosuppressive drugs

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

Give an example of a primary immunodeficiency

A

X-Linked agammaglobulinemia

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

Give an example of a secondary immunodeficiency

A

Acquired Immunodeficiency Syndrome (AIDS) -> caused by HIV

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

List the causes of secondary immunodeficiency
(7)

A

Malnutrition

Diseases e.g. HIV

Genetic and metabolic diseases

Immunosuppressive drugs

Surgery and trauma splenectomy

Age extremes: prematurity and old age

Environmental stress

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

How does malnutrition cause secondary immunodeficiency

A

Clinical obesity has negative effects on natural killer cells

Lack of NK activity -> increased viral infections and cancer in clinically obese

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give an example of an environmental stress that causes secondary immunodeficiency

A

Cigarette smoking

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

How can surgery and trauma cause secondary immunodeficiency?
(3)

A

Splenectomy

B cell populations lost

Knock on effects

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

What are the ten warning signs of primary immunodeficiency (will come up on the exam)

A

Four or more new ear infections within one year

Two or more serious sinus infections within one year

Two or more months on antibiotics with little effect

Two or more pneumonias within one year

Failure of an infant to gain weight or grow normally

Recurrent, deep skin or organ abscesses

Persistent thrush in mouth or fungal infections on skin

Need for intravenous antibiotics to clear infections

Two or more deep-seated infections including speticemia

A family history of primary immunodeficiency

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

How have primary immunodeficiencies facilitated our understanding of how the immune system functions?

A

By highlighting the effects of the absences of particular proteins

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

What causes most PIDs

A

Caused by mutant genes that confer no selective advantage to the individuals that carry them

They vary in severity from mild to fatal if the defect is not corrected or the infections are not prevented

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

List the different categories of primary immunodeficiency
(6)

A

Antibody deficiencies

Combined cellular and antibody deficiencies

Cellular deficiencies

Phagocytic cell deficiencies

Complement deficiencies

Very rare -> immune regulation deficiency (AIRE defect)

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

What are CIDs

A

Combined Immunodeficiencies

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

Write a note on combined immunodeficiencies
(3)

A

Among the most severe PIDs

Result from an absence of T cells, or impaired T cell function, combined with some disruption of antibody response

No T helper cells needed for B cell activation -> no antibody production

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

What causes CID
(3)

A

Absence of T cells

Impaired T cell function

Combined with some disruption of antibody response

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

What does a T cell deficiency do?
(3)

A

Results in no B cell activation

Results in no antibody class switching

Reduction in cell mediated cytotoxicity, therefore an increase in viral, protozoal, fungal and mycobacterial infections is observed

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

Write about SCID

A

The most extreme forms of CID

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

What gene defects can cause CID?
(5)

A

CD3 chains

Mitochondrial adenylate kinase

RAG1 and RAG2 or Artemis

Common y chain and JAK3

Adenosine deaminase (ADA) or purine nucleoside phosphorylase (PNP)

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

What do defects in adenosine deaminase or purine nucleoside phosphorylase do?
(3)

A

Nucleotide metabolites accumulate

These are particularly toxic to developing T cells and less so to developing B cells

Autosomally inherited

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

What does ADA stand for?

A

Adenosine deaminase

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

What does PNP stand for?

A

Purine nucleoside phosphorylase

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

Write about common y chain and JAK3 and how they cause SCID

A

Common y chain is X linked

JAK3 is autosomally inherited

Lack of signalling or signal transduction

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

Write about RAD1 and RAG2 or Artemis

A

No T cell receptors

No Antibody production

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

Write about CD3 chains and how they cause SCID

A

No T cell receptor complex expression for signalling

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

Write about mitochondrial adenylate kinase and how they cause SCID

A

Defective differentiation of myeloid and lymphoid lineages from stem cells

Reticular dysgenesis

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

What are antibody deficiencies?

A

A diverse spectrum of diseases

Ranges from the complete absence of mature recirculating B cells, plasma cells and Abs to the selective absence of certain classes of Abs e.g. IgA deficiency

Patients with these inherited deficiencies usually experience recurrent bacterial infection (caused by encapsulated bacteria) but have normal immunity to most viral and fungal infections

28
Q

What happens to patients with antibody deficiencies?
(2)

A

Experience recurrent bacterial infection (caused by encapsulated bacteria)

Have normal immunity to most viral and fungal infections

29
Q

Describe the different types of antibody deficiencies

A

Ranges from the complete absence of mature recirculating B cells, plasma cells and Abs to the selective absence of certain classes of Abs e.g. IgA deficiency

30
Q

Write a note on X-Linked Agammaglobulinemia
(6)

A

Originally called Bruton’s agammaglobulinemia

Patients have extremely low Ab levels

Babies born with this have virtually no B cells in peripheral blood

Suffer from recurrent bacterial infections

It is caused by a defect in the gene coding for the enzyme Bruton’s tyrosine kinase (Btk) which is involved in B cell development

Developing cells in the basal membrane are arrested at the pre-BCR stage

31
Q

What is X-Linked Agammaglobulinemia originally called

A

Bruton’s agammaglobulinemia

32
Q

What are the characteristics of XLA
(3)

A

Extremely low Ab levels

Babies have virtually no B cells in their peripheral blood

Suffer from recurrent bacterial infections

33
Q

What causes XLA?
(3)

A

A defect in the gene coding for the enzyme Bruton’s tyrosine kinase (Btk)

This enzyme is involved in B cell development

Developing cells in the BM are arrested at he pre-BCR stage

34
Q

Write a note on phagocytic deficiencies
(3)

A

PIDs which result in depressed numbers of phagocytic cells or faulty cell motility, adherence, phagocytosis and intracellular killing of microorganisms

Phagocytosis mediated by macrophages and neutrophils is the principle way the immune system gets rid of infecting bacteria and other microbes

Any defect that compromises phagocyte activity had profound effects on the immune system’s capacity to clear infection

35
Q

What are the characteristics of phagocytic deficiencies
(5)

A

Depressed numbers of phagocytic cells

Faulty cell motility

Faulty adherence

Faulty phagocytosis

Faulty intracellular killing of microorganisms

36
Q

Write a note on leucocyte adhesion deficiency
(4)

A

LADI is caused by a mutation in the CD18 gene

CD18 is the B chain of B2 integrins that include CR3. CR4 and LFA-1, all vital for the adhesion cascade

As CR3 and CR4 also function in the complement system phagocytes are unable to engulf microbes opsonised by C3b and C4b

Patients display omphalitis, gingivitis and recurrent infections

37
Q

What causes LADI

A

A mutation in the CD18 gene

38
Q

What is CD18
(3)

A

CD18 is the B chain of B2 integrins

including, CR3, CR4 and LFA-1

All of these are vital for the adhesion cascade

39
Q

What does loss of CR3 and CR4 do?
(2)

A

CR3 and CR4 play a role in the complement system

Phagocytes are unable to engulf microbes opsonised by C3b and C4b

40
Q

List some symptoms of LAD1
(3)

A

Patients display omphalitis

Gingivitis

Recurrent infections

41
Q

What does a C3 deficiency do

A

Susceptibility to a wide range of pyogenic infections

42
Q

What does a C5-C9 and properdin deficiency do?

A

Susceptibility to Neisseria

43
Q

What does a C1, 2 and 4 deficiency do?

A

Immune complex disease

44
Q

What does MBL deficiency do

A

Increased susceptibility to bacterial and fungal infections

45
Q

What does DAF or CD59 deficiency do

A

Autoimmunity

Paroxysmal nocturnal haemoglobinuria - erythrocytes are destroyed

46
Q

What does C1 inhibitor deficiency do?

A

Hereditary angioedema (HAE)

Bouts of swelling of the face, larynx and abdomen

The classical pathway is overactive - low C2 and C4 and raised C2a (vasoactive component)

47
Q

What is the role of the clinical immunology laboratory in the diagnosis of primary immunodeficiency
(6)

A

Detection of autoantibodies -> ELISA, immunofluorescence (direct and indirect)

Measurement of antibody levels - nephelometry

Measurement of specific antibody responses

Monitoring of serum proteins via serum protein electrophoresis

Measurement of complement levels/function - nephelometry, CH50, CH100 and AP50 assays

Leukocyte number/functions - flow cytometry

48
Q

Why would we measure specific antibody responses

A

Response to vaccination

IgE to allergens

49
Q

Why would we monitor serum proteins via serum protein electrophoresis?

A

Detection/characterisation of monoclonal gammopathy (SPE/IFE)

Detection of XLA via SPE

50
Q

List the methods of measurement of complement levels

A

Nephelometry

CH50 assays

CH100 assays

AP50 assays

51
Q

List the methods of measurement of leukocyte number/functions

A

Flow cytometry

52
Q

What are the principles of nephelometry
(3)

A

Add anti-sera for protein of interest (e.g. antibodies, C3, C4 and C1 inhibitor)

Where immune complexes form they will scatter light which can be detected

Standards can be used to calculate the concentration

53
Q

Nephelometry is used to detect what proteins

A

Antibodies

C3

C4

C1 inhibitor

54
Q

Name two brands of nephelometers

A

Roche COBAS 6000

Binding Site OPTILITE

55
Q

What is the principle of serum protein electrophoresis?
(3)

A

Electrophoresis is a method of separating proteins based on their physical properties

Serum is placed on a specific medium, and a charge is applied

The net charge (positive or negative) and the size and shape of the protein are used to separate and differentiate the various serum proteins

56
Q

Give an example of a machine for SPE

A

SEBIA Hydrasys SPE system

57
Q

List the different tests of the complement system
(2)

A

Haemolysis assays

Measurement of levels of complement components

58
Q

List the different types of haemolysis assays
(2)

A

CH50 and CH100 -> assays of the classical pathway

Ah50 - assay of the alternative pathway

59
Q

How are levels of complement components measured?

A

Measured via nephelometry

60
Q

What levels of complement components are measured via nephelometry

A

C3
C4
C1 inhibitor

61
Q

What is the principle of flow cytometry?

A

Flow cytometry is a technique for counting, examining and sorting microscopic particles suspended in a stream of fluid

Physical characteristics, size and granularity of particles are measured while fluorescently labelled antibodies can be used to examine protein expression

A laser beam is directed at a hydro-dynamically focused stream of fluid containing the cells in single cell suspension

A number of detectors measure properties such as forward scatter(size), side scatter (granularity) and fluorescence (specific protein expression) at different wavelengths

62
Q

What is measured via flow cytometry
(3)

A

Forward scatter(size)

Side scatter (granularity)

Fluorescence (specific protein expression)

63
Q

Give an example of a flow cytometer

A

FASCANTO II

64
Q

Flow cytometry is used in the diagnosis of what?
(4)

A

SCID

XLA

CGD

LADI

65
Q

What does SCID stand for?

A

Severe combined immunodeficiency

2.1 Molecular Immunology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions