Type I Immunopathology and Parasite Immunity Flashcards Preview

Blood and Lymph Unit 2 > Type I Immunopathology and Parasite Immunity > Flashcards

Flashcards in Type I Immunopathology and Parasite Immunity Deck (49):
1

What is the true role of IgE and Th2?

Fighting parasites

2

Is IgG produced in a person infected with worms?

Yes. and it activates complement and recruits neutrophils

3

Are neutrophils able to kill helminths?

No they lack a helminthocidal mechanism

4

When a mast cell binds antigens to it FcR the mast cell degranulates what does it release?

Anti-helminth IgE
Histamine
Prostaglandins
Leukotrienes

5

What does histamine do to the smooth muscle of the gut?

Increases contraction and violent peristalsis

6

What do the prostaglandins and leukotrienes do (released as ECF=A2)?

Attract eosinophils in large numbers

7

Eosinophils have Fc receptors that recognize IgG. How does that help it recognize the worm it needs to kill?

Because IgG is already opsonizing the worm at this point

8

What do the eosinophils do after the Fc receptor binds the IgG + helminth?

It releases the content of its granules Including Major Basic Protein which is highly toxic the the helminth

9

What is the role of Th2-like Tfh cells?

They go to the lymph node and help B cells switch to IgE production

10

What is the role of Th2 cells in helminth infection?

They go to the site of infection and attract both eosinophils and macrophages

11

What do Th2 cells produce to recruit eosinophils and macrophages?

IL-4
IL-5
IL-13

12

What do IL-4, IL-5, and IL-13 do to macrophages?

Activate them to the alternative M2 pathway where they heal damage and wall off M1-resistant invaders

13

Eosinophilia in the blood is indicative of what?

1. Parastie infection
2. Type II immunopathology

14

What are allergens?

Antigens that cause allergy

15

When will a mast cell degranulate?

When two adjacent IgE molecules are bound to the same antigen

16

What does histamine do the the bronchial smooth muscle?

Causes contraction

17

Is it common to see a type I immunopathology reaction to an antigen that can penetrate intact skin?

Uncommon

18

What is allergic rhinitis?

Seasonal (August and September) allergy to ragweed

Causes runny nose and itchy eyes

19

What is eczema?

Chronic dry and easily irritated skin, itch, and rash caused by an allergen

Secondary bacterial infections are common

20

What is oral allergy syndrome?

Almost immediate allergy to foods that causes tingling lips and tongue, itching, and swelling of the lips

ONLY oral cause stomach acid causes degradation of allergen

21

Asthma is considered both __________ and _________.

broncoconstrictive and inflammatory

It is important to avoid fibrosis

22

What is hyper IgE syndrome?

Autosomal Dominant condition
Inability to make INF gamma
So Th2 dominant
High IgE, skin abscesses and fungal and Pseudomonas pneuonia

23

What percentage of people experience allergic symptoms at some time in their life?

15%

24

A newborn with two parents who have allergies has a _____% of developing allergies.

65

25

Is the incidence of asthma on the rise or decline?

Rise

26

Give an example of a cross-reaction.

Cantaloupes cross-react with ragweed; people with ragweed rhinitis can have cantalouope oral allergy syndrome

27

What is atopic state?

Prone to develop any of the range of allergic syndroms

Infant with eczema can go on to have allergies to fish or milk, or develop asthma

28

Production of IgE is dependent upon what?

Tfh/ IL-4

29

IgE binds to that two cells that have Fc(epsilon)RI?

Basophils (found in blood)

Mast cells (found in tissue)

SUPER HIGH BINDING AFFINITY

30

What does degranulation release?

histamine
heparin
enzymes
TNF

31

What clinical symptoms does histamine produce?

Itch
Blood vessel dilation
leakiness

32

What occurs in the late phase reaction?

Phospholipase PLA2 cleaves arachidonic acid from membrane phospholipids

Converted into prostaglandins by COX and leukotrienes by lipoxygenase

33

What is the role of prostaglandins and leukotrienes?

They initiate inflammation, constrict bronchioles, and are together called "eosinophil chemotactic factor of anaphylaxis"

34

What are the two phases of Type I reactions?

Immediate phase
Late phase

35

Describe immediate phase

Due to histamine, so can be blocked by antihistamines

Antihistamines are receptor antagonists

36

Describe late phase

Onset: 4-10 hours

Dependent on prostaglandins, leukotrienes, and cytokines

37

Eosinophils are attracted to ECF-A and IL-4 what are these mediators produced by?

ECF-A is produced by Mast cells

IL-4 is produced by Th2

38

Name some things that can trigger bronchospasms in hyperreactive lungs.

Dry air
Irritants in the air
Viral infections
Cold

39

What is chronic spontaneous urticaria CSU?

IgG antibody against the Fc(epsilon)R1 on mast cells >>>>Chronic stimulation of histamine release

Tx: mAb omalizumab (binds to Fc or IgE so it can't bind to mast cells)

40

What is the most important diagnostic tool for diagnosing allergy?

History

41

Does a positive skin test conclusively mean that the patient is allergic to that allergen?

No. Cross-reactivity could be occuring

42

ImmunoCAP-FEIA is used to diagnose a specific allergen, but is it safe?

Yes. CAP testing is completely safe, unlike skin test which have some risk

43

What is asthma?

Reversible bronchoconstricitive disease with progressive inflammation leading to fibrosis

44

How is asthma diagnosed?

Spirometry-measures air flow

Measure FEV1- volume of air that can be forcibly exhaled from full lungs in 1 second

Then you measure FEV1 again once they get a bronchodilator treatment

45

Th2 in the lungs is proinflammatory. Why is this bad? How can you treat it?

Inflammation leads to fibrosis which is irreversible

Glucocorticoids

46

Antihistamines are effective for what phase of a type I reaction?

Immediate

47

How does epinephrine help treat anaphylaxis?

Constricts blood vessels, but dilates bronchial smooth muscle

48

What is the role of the following in the treatment of type I reactions:

-Glucocorticoids

-Leukotriene Inhibitors

-Rescue Inhalers

-LABAs (Lone-Acting Beta-2 Agonists)

-IgE blocker

-Immunotherapy

-Glucocorticoids: Local anti-inflammatory. Systemic has a lot of side effects. Block PG and LT synthesis and cause apoptosis in eosinophils

-Leukotriene Inhibitors: Block either synthesis (Zileuton) or binding (Montelukast)

-Rescue Inhaler: Short-acting beta-2 antagonist

-LABAs: reduce bronchoconstriction (Fluticasone/salmeterol

-IgE blocker: Omalizumab

Immunotherapy: Dilute solution of allergen extracts mechanism not clear. Oral desensitization. Peanut allergen skin patch

49

What is the role of Nucala (mepolizumab)?

Humanized interleukin-5 antagonist monoclonal antibody. Reduces severe asthma attacks by reducing the levels of blood eosinophils