Immunopathology of Infectious Diseases Flashcards Preview

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Flashcards in Immunopathology of Infectious Diseases Deck (45)
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1
Q

what is the first line of defense of the immune system?

A

physical barriers called Innate Immunity

2
Q

What is the second line of defense of the immune system?

A

chemical barriers, protective cells and fluids and it inflammatory response also called innate immunity
(Inflammasone as inflammation promotor and regulator)

3
Q

What is the third line of defense of the immune response?

A

Specific immunity or adaptive immunity

4
Q

What are features of acquired immune response?

A

Specific
Adaptive
Discriminates between self and non self
Has memory
Exhibits self tolerance
Appropriate (respond to the invader at hand)
Success depends on the immuno competancy and repertorie of Ag found in the genes of the individual

5
Q

Failure of the innate system can result in what?

A

Immunopathology

6
Q

Invaders must breach the innate barriers and be immunogenic to evoke what?

A

An adaptive immune response

7
Q

What are the immune response-cooperative effector mechanisms??

A
  1. Complement
    - -classical pathway: IgM and IgG = cell lysis and opsonization
    - -alternative (properdin) pathway
    - -IgM and IgG with complement
    - -Lectin Pathway
  2. Phagocytosis enhanced by opsonins
  3. Increased aggressive behavior of cellular immunity (CMI)
8
Q

In the lectin pathway of the complement system, mannose binding protein binds to non reduced mannose, fucose and glucosamine working to activate complement through what ?

A

C3 convertase

9
Q

What two complement factors are for inflammation?

A

C3a and C5a

10
Q

What complement factor is for opsonization?

A

C3b

11
Q

Complement levels in circulation can be used as what?

A

As a diagnostic feature of disease process

12
Q

The alternate pathway of the complement system is what?

A

Activated by bacterial cell surfaces, components (endotoxin, microbial polysacharrides, Aggregated IgA

13
Q

What are the clinical stages of infection?

A
  1. Aborted infection, no immune reaction
  2. Prodromal
  3. Inapparent infection (no overt symptoms or signs) (immune response may be observed)
  4. Sub Clinical infections (mild symptoms or signs) and (maliase not feeling good but does not go to a physician)
  5. Clinical infection, presents to clinician for diagnosis and possible treatment
  6. Clinical infection: fulminating, acute, subacute, chronic, inapparent
14
Q

Bacteria cause disease by what?

A

Toxin production, invasion or both

15
Q

Viruses cause pathogenesis by alteration of what?

A

alteration of cell function or structure, destruction of cell or both

16
Q

The immune response to invasion (lag time) consists of what?

A
  1. Destruction or elimination of invader
  2. Protection from infection
  3. Lack of an immune response
  4. abnormal response with subsequent pathology
17
Q

Why does the immune system fail to detect non-self in microbial populations?

A

Micropopulations also have strategies!
-Concealment, Antigenic variations, immunosuppresion, minicry, molecular mimicry, tolerization, gaps in host’s immune repertoire, and upsetting the balance between antibody and Th1 and Th2 responses

18
Q

What are some additional microbial strategies for reasons why the immune system fails to detect microbial populations

A
  • Temporary immunosuppression by some viruses
  • Some microbial toxins are immunomodulators
  • Some microbes interfere with cell signaling between immune cells with cytotoxic T cells or with host responses
  • Some microbes interfere with local expression of immune response in the tissue
19
Q

What are some immune disorders a result of?

A

Immune Disorders

  • Hypersensitivity
  • Immunodeficiency
  • Immunosuppression (latrogenic or organic)
  • Inappropriate response (genetic or exposure)
  • Failure to clear in the infectious disease agent
  • Failure to recognize self
  • autoimmune diseases
20
Q

What are immunodeficiencies result of?

A

Immunodeficiency may result from:

  • genetic deficiencies
  • starvation
  • drug-induced immunosupression (steroid tx and cancer chemo)
  • Chemotherapeutic (suppression of tissue graft rejection)
  • cancer (Esp of immune cells)
  • disease (HIV/AIDS)
21
Q

Immunopathology and infectious diseases refers to what?

A

Damage to host cells by the effector systems of the immune response resulting from microbially-induced specific and non specific immune responses

22
Q

Immune response can be protective under some conditions, damaging under others. What are some circumstances this statement can apply to?

A
  • lack of an immune response
  • excessive/unlimited/uncontrolled –>damage
  • INFLAMMASONES
23
Q

What is an acute phase protein?

A

C-reactive protein (CRP)

24
Q

CRP is an acute phase protein produced by what? and during what?

A

produced by liver during inflammatory response

25
Q

If the CRP in a patient is increased, what would this be due to?

A

Rise is due to a rise in the plasma concentration of IL-6, which is produced in macrophages, endothelial cells and T -cells

26
Q

CRP blood test: if low risk what is the range and if high risk what is the range?

A

Low risk is less than 1mg/L

high risk is greater than 3mg/L

27
Q

Patients with an elevated basal levels of CRP are at an increased risk for what diseases?

A

diabetes, HTN or cardiovascular disease

28
Q

CRP receptor is located on what cell?

A

macrophage

29
Q

What are lifestyle changes that a patient can do to reduce their CRP?

A

Exercise, lose weight, STOP SMOKING, flaxseed, aspirin, niacin, statins and clean teeth

30
Q

What syndrome is associated with increased CRP?

A

Metabolic Syndrome (Syndrome X)

31
Q

Excessive immune and inflammatory responses triggers by the infection can cause what?

A

Can cause disease

32
Q

Acute-phase response to cell wall components (endotoxin), is what?

A

is a protective antibacterial response when limited and controlled

33
Q

Systemic and out of control responses can cause what?

A

life threatening symptoms associated with sepsis and meningitis –> septic shock

34
Q

Tissue damage induced by neutrophils, macrophages, and complement at the site of the infection and granuloma formation is induced by what?

A

induced by CD4 T cells and macrophages for mycobacterium tuberculosis can lead to tissue destruction

35
Q

What diseases are associated with acute phase response?

A
  • M-protein of S. pyogenes antigenically mimics heart tissue (such that anti-M protein antibodies cross react with heart muscles to cause damage)
  • Chlamydia, Treponema (Syphilis), Borrelia (Lyme disease) and other bacteria the host immune response is an important cause of disease symptoms in patients
36
Q

There are 4 types of hypersensitivity disorders, each card will go through one. First, hypersensitivity I (immediate) –>

A

Type I: onset time is less than 30 mins

37
Q

what are features of hypersensitivity reaction type II?

A

Type II: Hypersensitivity: onset time- less than 8 hours

38
Q

what are features of hypersensitivity reaction type III?

A

Type III Hypersensitivity: onset time: less than 8 hours

39
Q

what are features of hypersensitivity reaction type IV?

A

Type IV hypersensitivity: Onset time: 24-72 hours (Acute) > 1 week chronic
Key features: soluble antigen presented to CD4 T cells by MHC II leads to release of TH1 cytokines, activating macrophages and cytotoxic T lymphocytes
Beneficial effects: protection against infection by fungi, intracellular bacteria and viruses
Pathological effects: contact dermatitis, TB skin test and Chronic: granuloma formation and graft rejection

40
Q

Type I immediate hypersensitivity requires the presence of what?

A

IgE (reaginic) Ab which binds to the Fc receptors on the mast cells and becomes a cell surface receptor for antigens.
this process can cause anaphylactic reactions which can be life threatening

41
Q

Type II hypersensitivity is mediated by what?

A

Antibody and complement.

complement activation promotes direct cell damage through the complement cascade and by the activation of effector cells

42
Q

What is an example of type II hypersensitivity?

A

Goodpastures syndrome
Response to Rh factor in newborns
autoimmune endocrinopathies
ADCC (Antibody-dependent cellular cytotoxicity)

43
Q

Type III hypersensitivity consist of immune complex deposition. These immune complexes can be trapped where?

A

In the kidneys and elsewhere in the body, can activate complement, and can cause other damaging responses.
Examples: serum sickness, nephritis associated with chronic Hep B infection and Arthus infection

44
Q

What is a double dimension agar gel immunodiffusion?

A

Gel diffusion for examination of multiple systems of soluble Ag Ab
Clarified agar gel is used as a matrix for combining diffusion with precipitation. The reactions simply diffuse through
Reactant diffuse to each other at the equivalence points
Line of precipitation

45
Q

Type IV delayed type hypersensitivity (DTH) is mediated by CD4 T cells. In this case, chemically modified self proteins are processed and presented to CD4 T cells, which release cytokines that promote what?

A

Inflammation

examples: tuberculin response and reaction to metals such as nickel.