Primary immunodeficiency Flashcards

1
Q

What are the hallmarks of recurrent infections encountered in immune deficient patients (SPUR)?

A

Serious infection
Persistent
Unususual
Recurrent

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

What are the stages of phagocyte production, mobilisation and recruitment that can be affected by immune deficiencies?

A
  1. mobilisation of phagocytes from bone marrow
  2. upregulation of ednothelial adhesion molecules. Neutrophils adhere and migrate into tissues.
  3. Recognition of the pathogen
  4. Phagocytosis of the pathogen.
  5. Activation of other immune system components.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Failure to produce neutrophils?

A
  • Recticular dysgenesis (primary, severy inborn SCID)
  • Following cell transplantation (secondary defect)
  • Kostmann sydndrome
  • Cyclic neutropaenia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When does Kostmann sydnrome present?

A

2 weeks after birth, with recurrent bacterial infections.

Treat with:

  • stem cell transplantation
  • stimulate neutrophil maturation with growth factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the clinical features of leukocyte adhesion deficiencies?

A
  • recurrent infections of deep tissues

- very high blood neutrophil counts

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

What receptors can be faulty in defects of phagocyte’s direct recognition of pathogens?

A

Toll-like receptors
Scavenger receptors
Lectin receptors
-They recognise bacterial wall structures.

Fc and complement (CRI) receptors:
-bind antigen-bound opsonins

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

Failure to phagocytose and kill pathogens?

A

-Chronic granulomatous disease (failure of oxidative killing mechanisms)

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

What are the features of Chronic granulomatous disease?

A
  • recurrent Staph, Aspergillus and pseudomonas infections
  • atypical mucobacteria
  • fungal infections
  • failure to thrive
  • hepatosplenomegaly
  • failure to thrive
  • granulomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Lab diagnostic test for chronic granulomatous disease?

A

NBT (nitroblue tetrazolium) test - can neutrophils kill pathogens by producing ROS?

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

What is the IL-12 : IFN-gamma network?

A

Defence against intracellular pathogens:

  1. Infected macrophages produce IL-12
  2. IL-12 induces Th1 cells to secrete INF-gamma
  3. INF-gamma loops back to stimulate oxidative killing pathways by macrophages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where do T cells undergo maturation and proliferation?

A

the Thymus

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

How are T cells formed?

A
  • arise form haematopoietic cells in the bone marrow
  • maturation and selection in the thymus
  • entry into circulation and lymph nodes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Functions of T cells?

A
  • defend against intracellular pathogens (bacteria, viruses)

- immunoregulation (helper T cells)

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

Functions of CD4+ T (helper) cells?

A

Immunoregulation:

  • activate CD8+ (cytotoxic) T cells and naive B cells
  • secrete cytikines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What antigenic peptides do CD4+ / T helper cells recognise?

A

Those bound to MHC class II

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

CD8+ (cytotoxic) T cells recognise antigenic peptides…

A

…presented bound to MHC class II

17
Q

How do cytotoxic T cells kill cells?

A
  • produce pores using perforin
  • induce apoptosis of target cells
  • secrete INF-gamma
18
Q

Cytotoxic T cells are important in defence against…

A

…viral infections and tumours.

19
Q

In recticular dysgenesis there is a failure to produce…

A

…neutrophils, B cells, T cells, Macrophages and platelets.

Death occurs without bone marrow transplantation.

20
Q

In SCID (severe combined immunodeficiency) there is a failure to produce…

A

… lymphocytes (B cells and T cells)

21
Q

What is X-linked SCID?

A
  • mutation in the IL-2 receptors

- T calls, NK cells and B cells cannot respond to cytokines

22
Q

SCID is treated with…

A

…stem cell transplantation

Gene therapy may work.

23
Q

The clinical features of DiGeorge syndrome are?

A
  • failed thymus development (no mature T cells)
  • congenital heart defects
  • cleft palate
  • hypoparathyroidism
  • schizophrenia, OCD
24
Q

CPx of DiGeorge syndrome?

A

Recurrent viral, bacterial and fungal infections

25
Q

Di George Syndrome - lab results?

A
  • no T cells
  • low B cells (or normal)
  • low IgG, IgA and IgE
26
Q

How do antibody deficiencies present?

A
  • recurrent bacterial infections (resp, GI)

- Ig-mediated autoimmune disease

27
Q

What is Bruton’s X-linked hypohammaglobulinaemia?

A
  • a B cell maturation defect
  • there are no circulating B cells or plasma cells
  • no circulating antibodies
28
Q

What Ig’s are low in Common variable immune deficiency?

A

IgG
IgA
IgE

Autoimmune and granulomatous disease are common.

29
Q

Characteristics of B cell deficiencies?

A

-recurrent bacterial infections by common / opportunistic bacteria