Ch. 7 Hypersensitivity

Front 1

What are inappropriate immune responses called?

Back 1

Hypersensitivity

Front 2

What is characterized by immune mechanisms that initiate inflammation and result in the destruction of healthy tissue

Back 2

Hypersensitivity

Front 3

T/F The inappropriate reaction to an antigen takes place after re-exposure (not immediately).

Back 3

True

Front 4

T/F All hypersensitivities are not life threatening

Back 4

False - they may all be life threatening.

Front 5

What may all hypersensitivities be?

Back 5

Immediate or Delayed

Front 6

What kind of hypersensitivity occurs in minutes to a few hours?

Back 6

Immediate hypersensitivity

Front 7

What type of hypersensitivity takes several hours and are at maximum severity days after re-exposure?

Back 7

Delayed Hypersensitivity

Front 8

What is a exaggerated immune responses against environmental antigens?

Back 8

Allergy

Front 9

What kind of hypersensitivity is most common and least threatening?

Back 9

Allergy

Front 10

What are either haptens or small-molecular-weight proteins?

Back 10

Allergens

Front 11

What are the following:
-Pollens (tree, grass, and weed)
– Molds and fungi
– Foods (milk, egg, fish, wheat)
– Animals (cat and dog dander)
– Cigarette smoke
– Components of house dust (dust mites)
– Medications (penicillin, sulfa)

Back 11

Allergens

Front 12

What is a misdirected immune responses against the host’s own cells?

Back 12

Autoimmunity

Front 13

What is a disturbance in the immunologic tolerance of self-antigens?

Back 13

Autoimmunity

Front 14

What is it when the immune system reacts against self-antigens and destroys host tissues

Back 14

Autoimmunity

Front 15

What are produced during autoimmunity?

Back 15

auto-antibodies

Front 16

What is commonly found in older people?

Back 16

Autoimmunity

Front 17

What is part of the aging process may be a deterioration of tolerance to self-antigens?

Back 17

Autoimmunity

Front 18

What is immune responses directed against beneficial foreign tissue?

Back 18

Alloimmunity

Front 19

What is the immune system produces a reaction against cells and tissues of another individual

Back 19

Alloimmunity

Front 20

The following are a type of what:
1. Blood transfusion
2. Organ transplantation and grafted tissue
3. Fetus during pregnancy

Back 20

Alloimmunity

Front 21

The most severe immediate hypersensitivity reaction is called what?

Back 21

anaphylaxis

Front 22

What is a rapid response, occurring within minutes of re-exposure?

Back 22

anaphylaxis

Front 23

What are the types of anaphylaxis?

Back 23

Localized or systemic

Front 24

The following is an example of what: cutaneous anaphylaxis includes erythema (reddish skin), hives, edema.

Back 24

Localized anaphylaxis

Front 25

The following are examples of what:
-Itching and erythema (reddish skin)
– Vomiting, abdominal cramps, diarrhea
– Laryngeal edema, breathing difficulties, respiratory distress
– Anaphylactic shock: widespread edema causes decreased blood volume and blood pressure, which may result in vascular collapse, shock and eventually death

Back 25

Systemic anaphylaxis

Front 26

The following are examples of what:
– Generalized itching
– Numbness & tingling, commonly around face and mouth
– Hive-type skin irritation
– Difficulty breathing
– Tightening of the chest
– Weakness/dizziness
– Abdominal cramps, diarrhea, vomiting
– Rapid, weak pulse

Back 26

Anaphylactic Shock

Front 27

How many types of hypersensitivity reactions are there?

Back 27

Four

Front 28

What are Types I, II, and III hypersensitivity mediated by?

Back 28

Antibodies

Front 29

What is type IV hypersensitivity mediated by?

Back 29

T-Cells

Front 30

T/F Types I, II, and III are delayed, while type IV is immediate.

Back 30

False - Types I, II, and III are immediate, while type IV is delayed.

Front 31

Allergic rhinitis (mast cells)is an example of what type of hypersensitivity?

Back 31

Type I: IgE mediated Reactions

Front 32

What type of reaction is the most common?

Back 32

Type I Hypersensitivity

Front 33

What is produced by B-cells after exposure to an allergen (environmental antigen)?

Back 33

IgE Antibody

Front 34

T/F Repeated exposure to large doses of allergen elicit enough IgE to “sensitize” the person.

Back 34

True

Front 35

In a sensitized person, re-exposure causes IgE to initiate what?

Back 35

Mast Cell Degranulation

Front 36

What do mast cells release?

Back 36

Histamine

Front 37

What mediates the allergic response?

Back 37

Histamine Receptors

Front 38

What causes:
-Contraction of bronchial smooth muscles resulting in bronchial constriction and breathing difficulties
– Increased vasodilatation and vascular permeability resulting in edema

Back 38

The interaction of histamine with histamine receptors.

Front 39

Which tissues respond the most to histamine?

Back 39

- Skin: itching, swelling, hives
– GI tract: cramping
– Respiratory tract: constriction of airways
– Other tissue: conjunctivitis, rhinitis, edema of the larynx

Front 40

What is the general manifestation of a type I hypersensitivity?

Back 40

– Hypotension
– Irregular heart beat
– Anaphylactic shock

Front 41

What are examples of Type I hypersensitivity?

Back 41

- Hay fever
– Asthma
– Eczema
– Local anaphylaxis
– Systemic anaphylaxis

Front 42

Genetic predisposition: some individuals appear to be prone to allergies and are called what?

Back 42

Atopic

Front 43

What type of individuals:
– Produce higher concentration of IgE
– Their airways and skin are more responsive to stimuli

Back 43

Atopic Individuals

Front 44

If one parent has an allergy, what percent of the offspring develop allergies?

Back 44

40%

Front 45

If two parents have an allergy, what percent of the offspring develop allergies?

Back 45

80%

Front 46

T/F is higher in children of atopic mothers than fathers.

Back 46

true

Front 47

T/F Because allergic reactions can be life threatening, sensitized individuals can try to be in contact with the specific allergens.

Back 47

False - they should try to avoid the allergens.

Front 48

T/F Tests of IgE mediated allergy are available to determine the specific allergen.

Back 48

true

Front 49

What kinds of tests can be performed to determine specific allergens?

Back 49

Blood and Skin tests

Front 50

What are the following examples of:
– Injections of minute amounts of allergen in increasing doses over a prolonged period
– May reduce the severity of the allergic reaction in treated individuals

Back 50

Desensitization

Front 51

What is also known as antibody-mediated cytotoxic hypersensitivity?

Back 51

Type II: Tissue-specific Reactions

Front 52

What is a type of disease that is tissue-specific?

Back 52

– Graves disease
– Blood transfusion reactions
– Haemolytic disease of the newborn
– Autoimmune Haemolytic anaemia
– Drug reactions

Front 53

How are tissue specific antigens expressed?

Back 53

the plasma membrane of cells in specific tissues

Front 54

What begins with antibodies binding to tissue-specific antigens?

Back 54

Type II Hypersensitivity: Tissue Specific Reactions

Front 55

What end in the destruction of the target (host) cell by macrophages (or by NK Cells)?

Back 55

Type II Hypersensitivity: Tissue Specific Reactions

Front 56

What is caused by antigen-antibody (immune) complexes?

Back 56

Type III: Immune Complex mediated Reactions

Front 57

The mechanism of this includes:
1. Large quantities of antigen-antibody complexes (IgG and IgM) form in the blood
2. They are deposited in the capillaries’ walls (between the endothelial cells and the basement membrane)
3. The antigen-antibody complexes activate the complement system
4. Complement proteins and the antigen-antibody complexes attract leukocytes to the area, mostly neutrophils
5. The neutrophils attempt to ingest the immune complexes, but cannot because the complexes are bound to the tissue (capillary wall)
6. The neutrophils discharge their lysosomal enzymes (killing agents) into the tissue
7. This promotes massive inflammation which causes tissue damage
8. This leads to tissue death and hemo

Back 57

Type III: Immune Complex mediated Reactions

Front 58

What type of reactions are not organ-specific but occur mostly in the blood vessels of the skin, joints, and kidneys

Back 58

Type III: Immune Complex mediated Reactions

Front 59

Examples of this are:
– Systemic lupus erythematosus
– Skin lesions of syphilis and leprosy

Back 59

Type III: Immune Complex mediated Reactions

Front 60

What type of hypersensitivity is mediated by specifically sensitized T cells, does not involve antibodies?

Back 60

Type IV: Cell-mediated tissue destruction

Front 61

What kind of hypersensitivity is always a delayed reaction?

Back 61

Type IV: Cell-mediated Tissue Destruction

Front 62

What are the types of Type IV: Cell-mediated Tissue Destruction?

Back 62

Cytotoxic T cells (Tc) and Lymphokine-producing cells (Td)

Front 63

What attack and destroy target cells directly (by toxins)?

Back 63

Cytotoxic T Cells

Front 64

What produce lymphokines that recruit macrophages to phagocytose target cells

Back 64

Lymphokine-producing cells (Td)

Front 65

What are clinical examples of Type IV Cell-mediated tissue destruction?

Back 65

- Graft and transplant rejection
– Tumor rejection
– Autoimmune diseases
- contact with poison ivy and metals
– Interaction with certain drugs such as sulfa and penicillin

Front 66

What types of autoimmune diseases are Type IV?

Back 66

Rheumatoid arthritis &
Insulin-dependent diabetes mellitus

Front 67

The following is an example of what:
- Poison ivy or poison oak causes a delayed hypersensitivity reaction with lesions only at the site of contact
– The allergen is a plant resin, too small to induce an immune response (a hapten)

Back 67

Allergic Contact Dermatitis

Front 68

The following is an example of what:
- Drugs such as penicillin and sulfa are haptens
• Penicillin may cause anemia by binding to proteins on erythrocytes

Back 68

Interaction with certain drugs such as sulfa and penicillin causing Type IV hypersensitivity.

Front 69

What is the mechanism of type IV hypersensitivity?

Back 69

The allergen a hapten: a molecule that is too small to induce an immune response
– Haptens bind to a protein in host cells and only then the immune response is initiated
– When binding with host cell proteins, haptens become a neo-antigen (new antigenic determinant), which is recognized as foreign
– The immune system attacks the neo-antigen on the host cell’s membrane and destroys the cell

Front 70

What is a breakdown of tolerance, in which the body’s immune system begins to recognize self-antigens as foreign?

Back 70

Autoimmunity

Front 71

– Immunologic tolerance to self antigens develops during what period of gestation?

Back 71

Embyronic Period

Front 72

T/F The original insult that caused the autoimmunity response may be either apparent or not.

Back 72

True

Front 73

Apparent original insults include what?

Back 73

include drug-induced anemia and virus induced changes (such as rubella infection)

Front 74

Unnapparent original insults include what?

Back 74

include rheumatoid arthritis and systemic lupus erythematosus (SLE)

Front 75

T/F Most autoimmune diseases happen after preexisting infections that leave no trace.

Back 75

True

Front 76

What disease is the only autoimmune disease that has been associated conclusively with a preceding infection (group A streptococcal infection)?

Back 76

rheumatic heart disease

Front 77

What sex is autoimmune disease more prevalent in?

Back 77

females

Front 78

Are autoimmune diseases more prevalent in whites or blacks?

Back 78

blacks

Front 79

What age group are most autoimmune diseases found in?

Back 79

20-40 years old

Front 80

T/F There is a decreased incidence of autoimmune diseases in twins.

Back 80

False - there is an increased incidence.

Front 81

T/F In most autoimmune diseases there are only exacerbations.

Back 81

False - There are remissions and exacerbations.

Front 82

What disease does the following describe: TSH receptors are bound (Dr. S’s notes say ‘destroyed’ but they are actually bound) causing hyperthyroidism (the antibodies stimulate the
thyroid to produce hormone).

Back 82

Graves Disease

Front 83

What type of disease occurs when the acetylcholine receptors on muscle cells are destroyed causing muscular weakness?

Back 83

Myasthenia Gravis

Front 84

What type of disease is characterized when myelin cells, which surround and insulate axons of nerve cells are destroyed, leading to decreased nerve conduction?

Back 84

Multiple Sclerosis

Front 85

What type of autoimmune disease occurs when multiple tissues are attacked and destroyed?

Back 85

Systemic lupus erythematosus (SLE)

Front 86

What type of disease is a chronic, multisystem, inflammatory disease
and is one of the most common, complex, and serious autoimmune disorders?

Back 86

Systemic lupus erythematosus (SLE)

Front 87

What type of disease occurs when a large variety of auto-antibodies are produced against many self-components including Nucleic acids (DNA), phospholipids (cell membranes)and Erythrocytes, lymphocytes, platelets, clotting proteins?

Back 87

Systemic lupus erythematosus (SLE)

Front 88

What disease occurs when Circulating immune complexes composed of DNA and antibody are deposited and cause inflammatory lesions (tissue damage) in the kidneys, brain, heart, spleen, lung, GI tract and skin (type III hypersensitivity)?

Back 88

Systemic lupus erythematosus (SLE)

Front 89

What are the clinical manifestations of lupus?

Back 89

– Arthritis (90% of individuals with SLE)
– Rash (70-80%)
– Renal disease (40-50%)
– Hematological abnormalities such as anemia (50%)
– Cardiovascular disease (30-50%)

Front 90

Why is it extremely difficult to diagnose SLE?

Back 90

Because the signs and symptoms affect almost every system in the body and tend to come and go.

Front 91

What are the eleven clinical findings of SLE?

Back 91

1. Facial rash confined to the cheeks (wolf like face-lupus)
2. A scaling rash with raised patches
3. Photosensitivity: skin rash in sunlight
4. Oral or nasopharyngeal ulcers
5. Arthritis of at least two peripheral joints
6. Inflammation of serous membranes such as pleurisy and pericarditis
7. Renal disorders such as protein-uria
8. Neurologic disorders such as seizures or psychosis
9. Hematologic disorders such as hemolytic anemia, leukopenia or thrombocytopenia
10.Immunologic disorders
11.Presence of antinuclear antibody

Front 92

How many of the eleven clinical findings of SLE must be found simultaneously for diagnosis?

Back 92

Four of the eleven

Front 93

What occurs when an individual’s immune system reacts against antigen on tissue of other members of the same species?

Back 93

Alloimmunity

Front 94

What are two examples of alloimmunity?

Back 94

Transient neonatal disease & Transplant rejection and transfusion reactions

Front 95

What disease occurs when the maternal immune system becomes sensitized against antigens expressed by the fetus?

Back 95

Transient neonatal disease

Front 96

What disease occurs when the fetus is a hybrid between the mother and father and expresses paternal antigens that are not found in the mother, and occasionally, the fetal antigens cross the placenta and elicit an immune response in the mother?

Back 96

Transient neonatal disease

Front 97

What disease occurs when maternal antibodies may be transported to the fetal circulation to produce alloimmne disease in the fetus, and although the symptoms may be manifested immediately after birth (and may be fatal), the source of these antibodies (mother) is removed at birth, so if the symptoms are treated the disease will disappear?

Back 97

Transient neonatal disease

Front 98

What are examples of transient neonatal disease?

Back 98

Rh and ABO: maternal antibodies against erythrocyte antigens induce anemia in the child

Front 99

What disease is a common problem among infants immediately after birth. It is the result of the inability of the neonatal liver to clear bilirubin, a breakdown product of blood cells, from the blood. Neonatal jaundice is usually a self-limiting, mild disorder. The most commonly used treatment is ultraviolet light exposure, in which the infant is placed under an ultraviolet lamp for a few hours each day. The ultraviolet light breaks down bilirubin into a form which the infant liver can process and excrete.

Back 99

Jaundice

Front 100

What occurs when the immune system of a recipient (of either an organ transplant or a blood transfusion) reacts against antigens on the donor’s cells?

Back 100

Transplant rejection and transfusion reactions

Front 101

What occurs when with organ transplantation there is often an immune response of the recipient against HLA-antigens on the donated tissue
and this is a type IV, cell-mediated reaction?

Back 101

Graft Rejection

Front 102

What are methods to decrease the rejections of the graft?

Back 102

HLA matching of donor and recipient and the use of immunosuppressive drugs

Front 103

Without immunosuppressive drugs, an organ will be rejected how quickly?

Back 103

Within 2 weeks

Front 104

Depending on the amount of time that passed between transplantation and rejection, graft rejection is classified how?

Back 104

As hyperacute, acute, or chronic

Front 105

T/F Hyperacute rejections are common.

Back 105

False - they are rare.

Front 106

What kind of rejection is the following:
- Antibodies bind to the graft tissue immediately when blood returns to the area
• The graft turns white immediately, due to inflammatory responses including the clotting cascade, which result in stoppage of blood flow to the graft
• Usually occur in recipients with preexisting antibodies to the antigens in the graft

Back 106

Hyperacute

Front 107

What type of rejection is the following:
– A type IV, cell-mediated immune response
– Occurs about 2 weeks after transplantation
– The recipient develops an immune response against the unmatched HLA antigens
– Immunosuppressive drugs may delay or lessen the intensity of acute rejection

Back 107

Acute

Front 108

What type of rejection is the following:
– May occur after months or years of normal function
– Characterized by a slow and progressive organ failure due to inflammatory damage to endothelial cells lining blood vessels
– As a result of a weak immune reaction against minor histocompatibility (HLA) antigens on the grafted tissue

Back 108

Chronic

Front 109

What type of reaction is IgE-mediated allergic reactions and is always allergens?

Back 109

Type I

Front 110

What type of reaction is tissue-specific reactions; autoimmune disease and blood transfusion (alloimmunity)?

Back 110

Type II

Front 111

What type of reaction is an autoimmune disease?

Back 111

Type III

Front 112

What type of reaction is cell -mediated reactions; allergens (contact dermatitis) and alloimmunity (transplant rejection)?

Back 112

Type IV

Front 113

How many types of stimuli for reactions are there?

Back 113

Three

Front 114

What are the three different types of stimuli?

Back 114

Allergy, autoimmunity, and alloimmunity