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Pathology Pt. 2 > Immune System Diseases > Flashcards

Flashcards in Immune System Diseases Deck (54)
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1
Q

Name the five major components of the innate immune system.

A
  1. Epithelial barriers
  2. Phayocytic cells (neutrophils, macrophages)
  3. Dendritic cells
  4. NK cells
  5. Plasma proteins (complement)
2
Q

What are the four types of hypersensitivity reactions? Briefly describe each one.

A
Type 1 (allergic hypersensitivity - IgE)
Type 2 (abnormal Abs)
Type 3 (immune complex)
Type 4 (delayed, T cell mediated)
3
Q

Allergens activate TH2 CD4+ T cells, which secrete cytokines ______ and ______, activating plasma cells to secrete Ig__ and IgG4.

A

IL-4 and IL-13 activates plasma cells to make IgE and IgG4

4
Q

Mast cells become _______ by binding Fc portions of IgE to their surface receptors.

A

sensitized

5
Q

Describe the two phases of a Type 1 hypersensitivity reaction.

A

Initial rapid response (from 5 min to 60 min after exposure) results in vasodilation, increased vascular permeability, and smooth muscle spasm.

Late phase (delayed - from 2-8 hours after exposure) involves inflammation and tissue destruction with infiltration of neutrophils, eosinophils, and T cells with secretion of lipid mediators and cytokines.

6
Q

Systemic anaphylaxis is an example of Type __ hypersensitivity that involves pruritus (itching), urticaria (hives), erythema, bronchoconstriction followed by laryngeal edema that may escalate to laryngeal obstruction and hypotensive shock. Can be fatal in minutes to hours.

A

Type 1 hypersensitivity

7
Q

What causes Type 2 hypersensitivity reactions? Name the three mechanisms of tissue destruction.

A

Abnormal antibodies that bind to cellular antigens, causing one of three things:

  1. Opsonization and phagocytosis
  2. Inflammation
  3. Antibody-mediated cellular dysfunction
8
Q

What causes inflammation during a Type 2 hypersensitivity reaction?

A

Complement activation products recruits polymorphs, monocytes, and phagocytic cells.

9
Q

Myasthenia gravis and Grave’s disease are examples of what type of destructive mechanism of Type 2 hypersensitivity reactions?

A

Ab-mediated cellular dysfunction.

10
Q

How do Type 3 hypersensitivity reactions cause inflammation?

A

Antibody-antigen complexes get trapped in small vessels of the body, bind complement, and cause vessel wall damage.

11
Q

Which antibody subtypes are involved in Type 3 hypersensitivity reactions?

A

IgG and IgM

12
Q

Name five symptoms of a Type 3 hypersensitivity reaction.

A
  1. Fever
  2. Urticaria
  3. Arthralgias (joint pain)
  4. Lymph node enlargement
  5. Proteinuria
13
Q

What is an Arthus reaction?

A

A local immune complex (Type 3) reaction. Localized reaction with tissue vasculitis and necrosis that peaks at 4-10 hours after Ag exposure.

14
Q

What causes Type 4 hypersensitivity reactions?

A

Overreaction of T cells

15
Q

Type 1 diabetes mellitus, MS, RA, peripheral neuropathies like Guillan-Barre syndrome, IBD, and contact dermatitis are all examples of Type __ hypersensitivity.

A

4

16
Q

Which T cell subtype is involved in cytokine secretion during a delayed-type hypersensitivity reaction?

A

Th1 CD4+ cells

17
Q

Granuloma formation during a delayed hypersensitivity reaction occurs due to a ________ antigen. In this process, initial perivascular CD4+ T cells are progressively replaced by ________ over 2-3 weeks, which then turn into epitheloid cells and may later turn into multinucleated giant cells.

A

occurs due to a persistent antigen. T cells replaced by macrophages that can turn into epitheloid, then multinucleated giant cells

18
Q

T-cell mediated cytotoxicity is a subtype of Type ___ hypersensitivity that involves the generation of ____ T cells in response to viral infections, tumor cells, or allografts.

A

subtype of Type 4, generates CD8+ killer T cells

19
Q

How do CD8+ T cells inflict injury during T cell-mediated cytotoxicity?

A

Direct killing by perforin-granzyme or Fas-FasL

20
Q

Are autoimmune diseases more common in women than in men?

A

Yeah

21
Q

How do “susceptibility genes” relate to autoimmune diseases?

A

The susceptibility genes predispose people to generating self-reactive T cells involved in autoimmune diseases.

22
Q

Name four non-organ specific autoimmune diseases.

A
  1. Systemic Lupus Erythematosus
  2. Progressive systemic sclerosis
  3. Polymyotosis and dermatomyotosis
  4. Rheumatoid disease
23
Q

Name six organ-specific autoimmune diseases.

A
  1. Vitiligo - anti-tyrosine Abs
  2. Grave’s
  3. Hashimoto disease - anti-thyroid Abs
  4. Addison’s disease - anti-adrenal cortex Abs
  5. Type 1 DM - anti-islet cell Abs
  6. Myasthenia gravis
24
Q

What plasma components are involved in Systemic Lupus Erythematosus?

A

Immune complexes and antibodies

25
Q

Which population is most heavily affected by Systemic Lupus Erythematosus?

A

young women

26
Q

Name the disease: Antinuclear antibodies deposit in many tissues, causing pleural effusions, nephritis, arthritis, Reynaud’s phenomenon (numb fingertips), and butterfly rash (in 50% of patients).

A

Systemic Lupus Erythematosus

27
Q

At what age do primary immunodeficiency syndromes manifest?

A

6 months to 2 years when maternal Abs are lost.

28
Q

What causes secondary immunodeficiency?

A

Infection, malnutrition, aging, immunosuppression, irradiation, chemotherapy, or autoimmunity.

29
Q

Bruton’s X-linked Agammaglobulinemia is characterized by deficiency of __ cell maturation which predisposes the patient to recurrent _______ infections.

A

No B cell maturation predisposes patients to recurrent bacterial infections.

30
Q

What is the genetic defect in Bruton’s X-linked Agammaglobulinemia?

A

BTK (tyrosine kinase associated with the pre-B cell receptor) on the X chromosome. Results in inability to form Ig light chains.

31
Q

What is DiGeorge Syndrome?

A

Absence or underdevelopment of the thymus and parathyroid –> no T cells.

32
Q

What causes hypocalcemic tetany in patients with DiGeorge Syndrome?

A

No PTH –> abnormal calcium metabolism causing involuntary muscle contraction.

33
Q

What type of infections are patients with DiGeorge Syndrome susceptible to?

A

Viral, fungal, protozoal, and intracellular bacterial infections.

34
Q

What is SCID? Name two specific mutations that cause it.

A

Severe combined immunodeficiency - lack of B and T cells. ADA and IL-2 receptor gene mutations are two examples.

35
Q

Transplantation often triggers T and B cell reactions that target ____ molecules on the graft cells.

A

MHC

36
Q

Name the three types of rejection.

A
  1. Hyperacute
  2. Acute
  3. Chronic
37
Q

What causes hyperacute rejection and how fast does it happen?

A

Happens in minutes to hours due to pre-formed, circulating antibodies

38
Q

Describe the morphological changes that occur during hyperacute graft rejection.

A

Abs attack graft endothelial cells causing acute fibrinoid necrosis with lumen accumulation of fibrin and cellular debris.

39
Q

Which pharyngeal pouches develop into the thymus and parathyroid?

A

3rd and 4th

40
Q

What is responsible for acute graft rejection? How long does it take to occur? What are the morphological changes?

A

Due to T cells, but some Abs can be involved. Happens 10-14 days after transplantation. Morphological changes: interstitial mononuclear cell infiltration with mild edema and parenchymal injury. Ab response can cause obliterative vasculitis.

41
Q

How long does chronic graft rejection take? What are the morphological changes?

A

Months to years. Vascular changes, interstitial obliterative fibrosis

42
Q

What is primarily responsible for chronic rejection?

A

T cells and cytokines

43
Q

Is vascular obliteration more or less severe in chronic rejection (vs acute rejection)

A

less severe in chronic

44
Q

Graft vs. host disease can happen after _____ ______ transplantation.

A

Bone marrow

45
Q

What is amyloidosis?

A

Aggregation of amyloid in tissues.

46
Q

What is amyloid?

A

A heterogenous group of fibrillar proteins that accumulate within tissues and organs due to excess synthesis or resistance to descruction.

47
Q

How does amyloid stain with Congo Red stain in cross-polarizing light?

A

Apple green - that is how it is differentiated from other stuff that stains red.

48
Q

Are amyloid proteins deposited intra, or extracellularly?

A

extracellularly

49
Q

Can accumulation of amyloid produce pressure atrophy of adjacent parenchyma?

A

Yeah

50
Q

What are the four forms of amyloidosis?

A

Primary, secondary, familial, Alzheimer’s

51
Q

What is primary amyloidosis?

A

Typically found in multiple myeloma, amyloid is made up of Ig light chains (AL protein). Deposits found in kidneys, blood vessels, heart.

52
Q

What is secondary amyloidosis?

A

Amyloid derived from serum amyloid-associated protein (AA protein) produced by the liver. Deposits found in kidneys, liver, spleen.

53
Q

What is familial amyloidosis?

A

Amyloid made up of abnormal transthyretin. Deposits in nerves.

54
Q

Which amyloid is involved in Alzheimer’s? Where do they deposit?

A

Beta amyloid, deposits in neurons.