Respiratory - Immune Deficiencies 1 - Week 4 Flashcards Preview

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Flashcards in Respiratory - Immune Deficiencies 1 - Week 4 Deck (40)
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1
Q

Which acronym is used to prompt consideration of immune deficiencies?

A

SPUR

2
Q

What does SPUR stand for?

A

Serious infections, Persistent infections, Unusual infections, Recurrent infections

3
Q

What is meant by a ‘serious’ infection?

A

Not responsive to antibiotics

4
Q

What is meant by a persistent infection?

A

Early structural damage or chronic infections

5
Q

How is ‘recurrent infection’ classified?

A

2 major or one major and many minor infections in one year

6
Q

How do chronic infections develop?

A

Degranulation of neutrophils releases destructive enzymes which create the niche for chronic infection to develop

7
Q

What is the single greatest indicator of immune deficiency?

A

Family history of immune deficiency - they’re usually genetically encoded

8
Q

Give 3 symptoms (outwith SPUR) that may suggest immunodeficiency.

A

Failure to thrive, chronic diarrhoea, weight loss

9
Q

What is meant by secondary immunodeficiency?

A

Another condition/factor causes the immunodeficiency rather than the body itself

10
Q

Give 5 examples of conditions which may cause secondary immunodeficiency?

A

Extremes of age, infection (such as HIV), treatments (eg. immunosuppressants), malignancy, nutritional disorders

11
Q

What is the role of TNF-alpha in the innate immune response?

A

Triggers vasodilation & production of heat.

12
Q

Which of the leukocytes are phagocytes?

A

Macrophage & Neutrophil

13
Q

What are the typical clinical features of phagocyte deficiency?

A

Infection at unusual sites, common & unusual bacteria, typical & atypical mycobacterium, fungal infections

14
Q

State 2 reasons which can cause Neutrophils to not be produced or not be produced properly.

A

Failure to differentiate along the myeloid lineage or failure of naive neutrophils to mature

15
Q

Give a primary defect which would cause failure of a cell to differentiate along the myeloid lineage.

A

Reticular dysgenesis

16
Q

What is reticular dysgenesis?

A

Most severe form of Inborn Severe Combined Immunodeficiency (SCID) - no neutrophils & few lymphocytes –> Fatal septicaemia within days of birth

17
Q

Give a secondary defect which would cause failure of a cell to differentiate along the myeloid lineage.

A

After stem cell transplant

18
Q

Give 2 examples of conditions caused by failure of neutrophils to be able to mature.

A

Kostmann Syndrome, Cyclic neutropaenia

19
Q

What is the mechanism of reticular dysgenesis?

A

Stem cell cannot differentiate into common myeloid progenitor or common lymphoid progenitor

20
Q

What is the mechanism of Kostmann Syndrome?

A

Granulocyte-Monocyte progenitor cannot differentiate into a neutrophil as there is a defect in G-CSF cytokine or receptor

21
Q

State 4 clinical presentations of Kostmann Syndrome.

A

Severe chronic neutropenia, recurrent bacterial infections usually 2 weeks after birth, fever, irritability, failure to thrive

22
Q

State 2 supportive treatments of Kostmann Syndrome.

A

Prophylactic antibiotics & prophylactic anti-fungals

23
Q

State 2 definitive treatments of Kostmann Syndrome.

A

Stem cell transplantation (if problem in Neutrophil pre-cursor), G-CSF (if defect in cytokine)

24
Q

If a patient’s phagocytes were unable to bind to adhesion molecules, what clinical signs would be seen?

A

High neutrophil numbers in blood, no pus formation in tissue infections, recurrent bacterial & fungal infections

25
Q

Failure to recognise activation markers expressed on endothelial cells is called…

A

Leukocyte Adhesion Deficiency

26
Q

Leukocyte adhesion deficiency is caused by…

A

A defect in the CD-18 leukocyte integrin

27
Q

What kind of receptors do phagocytes express?

A

Fc

28
Q

What is the role of Fc receptors in phagocytes?

A

Allows any antibody-antigen complex to attach

29
Q

Which receptor on phagocytes binds to complement fragments bound to an antigen?

A

Complement receptor 1 (CRI)

30
Q

State 2 potential reasons behind defective phagocytosis.

A

Defect in opsonin receptors (Fc or CRI) or defect in complement or antibody production

31
Q

Failure of oxidative killing mechanisms is called…

A

Chronic Granulomatous Disease

32
Q

Chronic Granulomatous Disease results in…

A

inability of phagocytes to kill by oxidative killing as they cannot produce free radicals

33
Q

State 5 clinical features of Chronic Granulomatous Disease.

A

Recurrent deep bacterial infections, recurrent fungal infection, failure to thrive, Lymphadenopathy and hepatosplenomegaly (enlarged spleen & liver), granuloma formation

34
Q

Which test is used to test for Chronic Granulomatous Disease?

A

NBT test

35
Q

What does the NBT test test for?

A

Whether neutrophils can kill via production of oxidative free radicals

36
Q

Give 2 examples of supportive treatments for Chronic Granulomatous Disease.

A

Prophylactic antibiotics & anti-fungals

37
Q

Give 2 examples of definitive treatments for Chronic Granulomatous Disease.

A

Stem cell transplantation or Gene therapy

38
Q

Explain the immunological pathway involved in TB.

A

Infected macrophage produces IL-12 which stimulates Th1 cells to produce interferon gamma which acts on neutrophils & macrophages to produce TNF-alpha. This triggers oxidative killing mechanisms.

39
Q

IFNg receptor deficiency, IL-12 deficiency and

IL-12 receptor deficiency can all cause…

A

Increased susceptibility to mycobacterial infections

40
Q

Which tests may be involved with diagnosing phagocyte function deficiency?

A

Full blood count, presence of pus, Expression of neutrophil adhesion markers, Chemotactic assays, Phagocytosis assays, NBT test