Exam #3: Immunodeficiencies Flashcards Preview

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Flashcards in Exam #3: Immunodeficiencies Deck (28):
1

When should you be suspicious for an immunodeficiency?

- Unusually frequent, severe, resistant infections
- Refractory to treatment compared to patients of similar age & exposure risk

2

What is the difference between a primary & secondary immunodeficiency?

Primary= genetically determined
- Genetic defects in B or T lymphocytes
- Usually presents between 6 months & 2 years

Secondary= consequences of cancer, other infections, malnutrition, drugs

3

What are the clinical manifestations of primary immunodeficiencies?

- Recurrent infections
- Failure to thrive

4

What is the consequence of an ADA deficiency in lymphocyte development?

No pro-B or T cells

5

What is defect in lymphocyte development seen in X-Linked Agammaglobulinemia?

Pre-B cells are unable to mature

6

What is defect in lymphocyte development seen in Hyper IgM-Syndrome?

Lack of:
- CD40L
- Activation induced deaminase

*****Immature B-cells can mature into IgM but NOT other isotypes

7

What is defect in lymphocyte development seen in X-Linked SCID?

Cytokine gamma chain= pro T-cell cannot become immature T-cell

8

What is defect in lymphocyte development seen in Di George Syndrome?

Immature T-cell cannot mature

9

What is X-Linked Agammaglobuliemia of Burton?

- X-linked recessive disorder of males caused by mutation in Burton's Tyrosine Kinase (BTK)gene
- Responsible for B-cell maturation via pro/pre-B cell signal transduction

*****B-cells don't mature & can't produce antibodies

10

What is agammaglobulinemia?

No antibody production i.e. absence of mature B-cells in the blood

11

When does Burton's Agammaglobulinemia onset?

After maternal antibodies have been depleted, which is ~6months

12

What is the clinical presentation of Burton's Agammablobulinema?

- Recurrent sinusitis
- Oropharyngeal
- Respiratory infections

*****All due to pyogenic bacteria that would normally be opsonized by circulating antibodies

13

What are the three major pyogenic bacteria that are opsonized by circulating antibodies?

1) Staphylococcus aureus
2) Streptococcus pneumoniae
3) H. Influenza

14

What are the viral & protozoal infections are patients with Burton's Agammaglobulinemia are susceptible to?

Enteric viruses & giardia lamblia

15

What vaccination is especially dangerous for patients with Burton's Agammaglobulinemia?

Polio from live vaccine-->leads to paralytic polio

16

When does Burton's Agammaglobulinemia onset?

After maternal antibodies have been depleted

17

What is the treatment for Burton's Agammagloulinemia?

Parenteral immuoglobulin replacement

18

What is Common Variable Immunodeficiency?

Variable group of disorders that occur later in life

19

What are the mechanisms of Common Variable Immunodeficiency?

The mechanisms of CVID are variable and include:
1) Intrinsic B-cell defects
2) Abnormal T-cell signaling to B-cells

*****Both lead to an inability of B-cells to become plasma cells

20

What are the lab findings associated with Common Variable Immunodeficiency?

Hypogammaglobulinemia, usually all antibody classes but occasionally isolated IgG

21

What are the clinical features of Common Variable Immunodeficiency?

- Recurrent bacterial infections of the sinuses & respiratory tract
- Increased enteroviral infections & chronic diarrhea due to Giardia Lamblia infection
- Paradoxical increase in autoimmune disorders

22

What are patients with Common Variable Immunodeficiency at increased risk for?

- Autoimmune disorders
- B-cell Lymphoma
- Gastric Cancer

23

What are the lab findings associated with Common Variable Immunodeficiency?

Hypogammaglobulinemia, usually all Ab but occasionally isolated IgG

24

What is selective IgA deficiency?

Isolated IgA deficiency in which infected individuals have low levels of serum & secretory IgA

25

What is the most common immunodeficiency?

Selective IgA deficiency (European)

26

What is acquired IgA deficiency associated with?

- Measles
- Toxoplasmosis
- Other viral infections

27

Describe the clinical features of Selective IgA Deficiency.

IgA is the major Ig in secretions; thus, infections are common in the:
1) Respiratory
2) GI
3) GU tracts

28

What do you need to remember about patients with Selective IgA Deficiency?

Blood transfusion with blood containing normal levels of IgA can induce anaphylaxis