Primary Immunodeficiency Flashcards Preview

Pathology > Primary Immunodeficiency > Flashcards

Flashcards in Primary Immunodeficiency Deck (32):
1

What are frequent viral and fungal infection indicative of?

T cell disorder

2

What are frequent bacterial infections indicative of?

B cell disorder

3

What are the tests for B cell function?

– Serum protein electropheresis
– Quantitation of specific Ig levels in blood

4

What on the CBC can indicate a T cell disorder?

Lymphocytopenia

5

X linked agammaglobulinemia

Mutation in a signaling tyrosine receptor that is mandatory for growth and development of B cells- specifically BLK-critical for the pre-BCR signal

6

What is the only pure B cell defect?

X linked agammaglobulinemia

7

What are the findings with X linked agammaglobulinemia?

- No Ig
- No B cells

8

How is X linked agammaglobulinemia treated?

Pooled IVIG

9

Hyper IgM syndrome

Mutation of CD40L, known as CD154, on T cells

10

What is the inheritance pattern of Hyper IgM syndrome?

X-linked

11

What are the findings with Hyper IgM syndrome and why?

• High IgM, low IgG and IgA because B cells not
prompted to isotype switch
• Switch not possible because of inability of T cells to be
activated and provide the switch cytokines

12

Selective IgA “deficiency”

No IgA is found - not a "true" deficiency though

13

What are the findings with IgA deficiency?

• IgG and IgM levels are normal
• IgA absent

14

What is the problem of transfusions with IgA "deficiency?"

Clinical problem is that ~10% of patients may have IgG anti-IgA antibodies. These may cause anaphylactic reactions during RBC transfusion or IVIg infusions

15

EBV X-linked agammaglobulinemia

• Underlying defect is a mutation in a signaling regulator of CD8 cells
• The mutation is activated by EBV infection of B cells
• If patient survives the EBV, B cell depletion by
cytotoxic T cells ensues and causes agammaglobulinemia

16

How does EBV X-linked agammaglobulinemia lead to death?

Ultimately die of global immune system dysfunction
because CD8 autoimmune attack on immune effector cells

17

Common Variable Immunodeficiency (CVID)

Fundamental defect is the inability of a B cell to differentiate to a plasma cell.


18

What are the findings of CVID?

• Decreased IgG, A and M levels are first abnormalities coming out from a normal childhood
• Progresses to overt T cell symptoms and then multiple autoimmune diseases, especially in the gut-PA, Celiac disease

19

What does CVID often culminate as?

Lymphoma

20

Are there B cells present in CVID?

Yes! They just cannot differentiate into plasma cells

21

What is the treatment for CVID?

IVIG will work until T cell defects become prominent

22

Thymic aplasia

There is no thymus present - deletion of 22q11.2
• Structural mutations in the 3rd and 4th branchial pouches (also called pharyngeal arches) - associated with Tetralogy of Fallot

23

What is often found with thyme aplasia?

Absent or deficient parathyroid glands and symptomatic
hypocalcemia

24

What are the findings with SCID?

Decreased or absent TRECS

25

Pathogenesis of Wiskott-Aldrich Syndrome

X linked recessive mutation of the WAS gene (cytoskeletal regulation)

26

What are the signs of Wiskott-Aldrich Syndrome?

• Eczema
• Thrombocytopenia,
• Moderate T cell deficiency

27

What are the signs of Ataxia-Telangiectasia?

• Oculocutaneous telangiectasia
• Recurrent infection of all kinds
• High rate of neoplasia-esp leukemia/lymphoma
• Extreme sensitivity to radiation-induced DNA damage and faulty repair

28

Bare lymphocyte syndrome

Defects in formation and transport of MHC I and II complexes to the cell membrane

29

Job (hyper-IgE) syndrome

• Autosomal dominant
• Eczema, recurrent T & B cell infections
• High IgE, impaired T cell function- especially Th17

30

Chediak Higashi Syndrome

• Recessive mutation
• Decreased intracellular protein transport
• Azurophilic granule formation affected in Ly and PMN
• Albinism

31

Chronic Granulomatous Disease

• X linked recessive, can be one of several mutations in NADPH respiratory burst system

32

What are the complications of Chronic Granulomatous Disease?

• Neutrophils can phagocytize but can’t kill because cannot generate sufficient hydrogen peroxide
• Infections with catalase + organisms (Staph, fungi) are frequent - catalase counters the baseline H2O2

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