Gen Path - Class 6

Front 1

What is a hypersensitivity disorder?

Back 1

An exaggerated or inappropriate immune response may lead to various hypersensitivity disorders.

Front 2

What is hypersensitivity?

Back 2

Designates an increased immune response to the presence of an antigen (allergen) that results in tissue destruction

Front 3

What causes the damage and suffering during/after an allergic reaction?

Back 3

The damage and suffering actually comes from the immune response itself rather than from the substance that provoked it.

Front 4

How many types of hypersensitivity reactions are there?

Back 4

Four

Front 5

What is a Type I hypersensitivity reaction?

Back 5

Anaphylactic

Front 6

What is a Type II hypersensitivity reaction?

Back 6

Cytotoxic antibody mediated

Front 7

What is a Type III hypersensitivity reaction?

Back 7

immune complex mediated

Front 8

What is a Type IV hypersensitivity reaction?

Back 8

cell mediated, delayed hypersensitivity

Front 9

Describe a Type I hypersensitivity reaction.

Back 9

immediate hypersensitivity, allergic disorders, anaphylaxis. Mediated by IgE, mast cells, basophils.

Front 10

What is atopy?

Back 10

Genetically predisposed condition where IgE !b’s produced to common environmental allergens. eg. atopic dermatitis or eczema – generally most prevalent in children (improves with age, but may develop asthma or hay fever).

Front 11

At a cellular level, what happens during a first exposure with a Type I hypersensitivity reaction?

Back 11

First exposure -- Production of IgE by plasma cell -- binds to Fc receptor on mast cells

Front 12

What is an Fc receptor?

Back 12

A protein found on the surface of certain cells - including natural killer cells, macrophages, neutrophils, and mast cells - contribute to the protective functions of the immune system

Front 13

At a cellular level, what happens during a second exposure with a Type I hypersensitivity reaction?

Back 13

Second exposure -- Ag-Ab complex (The complex formed by the binding of an antibody and an antigen) -- immediate response -- histamine release & inflammatory mediators

Front 14

What happens if a Type I hypersensitivity reaction becomes systemic?

Back 14

IF response becomes systemic, wide spread release of histamine occurs (rather than just local tissue response) -- systemic vasodilation, blood pressure drop brochospasm, increased mucus secretion, edema -- ANAPHYLAXIS

Front 15

What are three examples of a Type I hypersensitivity reaction?

Back 15

(1)Hay fever/Environmental Allergies, (2)Anaphylactic shock, (3)Asthma

Front 16

What is anaphylactic shock?

Back 16

A severe allergic reaction that occurs rapidly and causes a life-threatening response involving the whole body.

Front 17

What three things can anaphylactic shock cause?

Back 17

(1)difficulty breathing, (2)Shock, (3)Death

Front 18

Anaphylactic shock is a severe response to an allergen leading to systemic histamine release causing these three reactions:

Back 18

(1)systemic vasodilation, (2)bronchospasm, (3)mucus & edema in airways and tissues

Front 19

How can anaphylaxis be treated?

Back 19

Administration of IM epinephrine (epipen) -- vasoconstriction

Front 20

What are three examples of triggers of anaphylaxis?

Back 20

(1)bee sting, (2)Penicillin, (3)foods

Front 21

Describe Type II hypersensitivity reaction.

Back 21

Cytotoxic reactions to self-antigens. Cytotoxic antibodies react with antigens in cells or tissues. Mediated by IgM or IgG – these form complexes with the antigen on cell membranes or ECM, and activate complement -- cell lysis or phagocytosis

Front 22

What are three mechanisms of a Type II hypersensitivity reaction?

Back 22

(1)Cells are marked by antibodies and compliment components for ingestion by phagocytes, (2)Inflammation is induced by the antibodies binding to the WBC, (3)Antireceptor antibodies disturb the normal function of the receptors leading to activation such as Grave’s or impairment such as Myasthenia gravis

Front 23

What are four examples of a Type II hypersensitivity reaction?

Back 23

(1)Hemolytic anemia, (2)Incompatible blood transfusion, (3)Grave’s disease, (4)Myasthenia Gravis

Front 24

What is hemolytic anemia?

Back 24

A condition in which red blood cells are destroyed and removed from the bloodstream before their normal lifespan is up. RBC antigens of these patients become antigenic and are recognized as foreign by the body’s own immune system.

Front 25

What is incompatible blood transfusion?

Back 25

Antibodies in patients blood react to antigens of transfused blood cells.

Front 26

What is Grave’s disease?

Back 26

Form of hyperthyroidism in women with Ab against the TSH receptor on thyroid -- goiter

Front 27

What is myasthenia gravis?

Back 27

Severe muscle weakness. Ab for Acetylcholine receptor on striated muscle. Acethylcholine is the NT released in the NM junction. Blockade leads to progressive weakness and even paralysis.

Front 28

Describe Type III hypersensitivity reaction.

Back 28

Immune complex disease. Ag-Ab complex formation -- instead of being cleared by the body, they deposit in tissues around small blood vessels. This leads to vasculitis–- inflammation of a blood vessel or blood vessels

Front 29

What are five reactions that vasculitis can lead to?

Back 29

(1)Wheals (inflammation of skin), (2)Synovitis (inflammation of joints) Ex. RA, (3)Nephritis (inflammation of kidneys), (4)Pleuritis (inflammation of pleura surrounding lungs), (5)Pericarditis (inflammation of pericardium)

Front 30

What are four examples of a Type III hypersensitivity reaction?

Back 30

(1)Serum sickness, (2)Systemic Lupus Erythematosus (SLE), (3)Polyarteritis Nodosa, (4)Post-streptococcal glomerulonephritis (PSGN)

Front 31

What is serum sickness?

Back 31

Ag-Ab complexes deposit in blood vessel walls and tissues, where they induce vascular and tissue damage resulting from activation of complement and granulocytes

Front 32

What causes serum sickness?

Back 32

Results from the injection of heterologous or foreign protein or serum. Currently, the most common cause of serum sickness is hypersensitivity reaction to drugs.

Front 33

What are five signs and symptoms of serum sickness?

Back 33

(1)Fever/malaise, (2)Cutaneous eruptions, (3)Arthralgias, (4)Gastrointestinal complaints, (5)HA -- self-limiting resolves is days

Front 34

What is Systemic Lupus Erythematosus (SLE)?

Back 34

Autoimmune disease of unknown origin. Antigen is person’s own nucleus of cells - Antinuclear antibodies (ANAs). Dx by immunofluorescence microscopy. Classic presentation is the triad of fatigue, joint pain and malar (butterfly) rash in women of childbearing age

Front 35

What body system(s) can Systemic Lupus Erythematosus (SLE) effect?

Back 35

Can affect any organ system. Kidney disease, arthritis, skin disease (malar (butterfly) rash).

Front 36

Describe what happens with Polyarteritis Nodosa.

Back 36

Medium sized arteries -- focal necrosis and acute inflammation -- destruction of vessel wall and micro aneurism formation -- thromboses -- infarcts

Front 37

What is Post-streptococcal glomerulonephritis(PSGN)?

Back 37

In PSGN an immune complex containing astreptococcal antigen is deposited in the affected glomeruli. Typically follows URTI caused by certain streptococci (The offending organisms are virtually always group Astreptococci.) Usually short-lived and resolves without serious sequelae.

Front 38

Describe Type IV hypersensitivity reaction.

Back 38

Cell-mediated or delayed-type immune response. Only one that is not Ab-mediated.

Front 39

What are two mechanisms of Type IV hypersensitivity reaction?

Back 39

(1)Delayed type, (2)Cytotoxic

Front 40

What is the delayed type mechanism of a Type IV hypersensitivity reaction?

Back 40

Helper or cytotoxic T cells respond to tissue antigens by secreting cytokines that stimulate inflammation and activate phagocytosis -- tissue injury

Front 41

What is the cytotoxic mechanism of a Type IV hypersensitivity reaction?

Back 41

In some cases, cytotoxic T cells directly kill tissue cells.

Front 42

What are two examples of a type IV hypersensitivity reaction?

Back 42

(1)Sarcoidosis, (2)Contact dermatitis

Front 43

What is sarcoidosis?

Back 43

Idiopathic granulomatous disease. Most commonly the lungs, lymph nodes, eyes and skin.

Front 44

What is contact dermatitis?

Back 44

Does not include granuloma but skin contains infiltrates of T cells and macrophages Examples: latex, poison ivy, “gold” rings containing Nickel

Front 45

What are autoimmune diseases?

Back 45

Abnormal B-cell / T-cell response to self involving B-cell auto-antibodies production or T-cell HLA recognition failure. *Human Leukocyte Antigen-Major Histocompatability Complex in humans. The body fails to distinguish self from nonself, causing the immune system to direct immune responses against normal (self)tissue and become self destructive.

Front 46

How many autoimmune diseases have been identified?

Back 46

56+. Some systemic (i.e. SLE, RA, MS). Some only affecting particular organs (Crohn’s, DM, Graves’ disease, beta cells in pancreas with type 1 diabetes).

Front 47

What is the etiology of autoimmune diseases?

Back 47

Although the autoimmune disorders are regarded as acquired diseases, their causes often cannot be determined.

Front 48

What are three suspected risk factors of autoimmune diseases?

Back 48

(1)No single gene has been identified as responsible for autoimmune diseases, (2)Clusters of genes seem to increase susceptibility, (3)In most autoimmune disorders, a known or suspected genetic susceptibility is evident, and certain HLA types show increased risk.

Front 49

What is believed to be the causes of autoimmune diseases?

Back 49

Autoimmunity is believed to result from a combination of factors, including genetic, hormonal (women are affected more often than men), and environmental influences(eg-exposure to chemicals, other toxins, or sunlight and drugs that may destroy suppressor T cells)

Front 50

What causes the immune response to become self-destructive?

Back 50

Autoimmune disorders involve disruption of the immunoregulatory mechanism, causing normal cell-mediated and humoral immune responses to turn self-destructive, resulting in tissue damage.

Front 51

What is a characteristic auto-antibodies?

Back 51

Many autoimmune diseases are associated with characteristic auto-antibodies. Basically, the body begins to manufacture antibodies directed against the body’s own cellular components or specific organs.

Front 52

What causes difficulty in differentiating autoimmune diseases?

Back 52

Autoimmune disorders share certain clinical features, and differentiation among them is often difficult because of this.

Front 53

What are 11 common findings of patients with autoimmune diseases?

Back 53

(1)Synovitis, (2)Pleuritis, (3)Myocarditis, (4)Endocarditis, (5)Pericarditis, (6)Peritonitis, (7)Vasculitis, (8)Myositis, (9)skin rash, (10)alterations of connective tissues, (11)Nephritis

Front 54

What are four common constitutional symptoms of patients with autoimmune diseases?

Back 54

(1)Fatigue, (2)Malaise, (3)Myalgias, (4)Arthralgias (joint pain/aches)

Front 55

What is Systemic Lupus Erythematosus (SLE)?

Back 55

Chronic inflamm collagen-vascular disease. Believed to be a defect in suppressor T cells polyclonal activity of B cells (ie uncontrolled cloning of B cells). Antigen-Antibody complexes form in skin and other tissues -- Type III Hypersensitivity reaction

Front 56

What are five signs/symptoms of Systemic Lupus Erythematosus (SLE)?

Back 56

(1)Skin rash (malar “butterfly” over cheeks & nose), (2)Vascular & joint inflammation, (3)Fibrosis of heart, lungs, kidney (poss renal failure); CNS/PNS problems, (4)Antinuclear-antibody (ANA) production affecting multiple tissues, (5)Anti-DS DNA and anti-Sm + in some people withSLE

Front 57

Is Systemic Lupus Erythematosus (SLE) more common in men or women?

Back 57

Young women

Front 58

What is scleroderma?

Back 58

chronic fibrosis of skin, joints, lungs, esophagus, GI, & kidneys; women. Can be referred to as systemic sclerosis.

Front 59

What are the limited symptoms of scleroderma referred to as?

Back 59

CREST

Front 60

What is CREST?

Back 60

C: Calcinosis - calcium deposits in the skin

R: Raynaud's phenomenon - spasm of blood vessels in response to cold or stress

E: Esophageal dysfunction: acid reflux and decreased motility of esophagus

S: Sclerodactyly - thickening and tightening of skin on fingers and hands

T: Telangiectasias - dilation of capillaries causing red marks on surface of skin (spider veins)

Front 61

What are 12 examples of organ specific autoimmune diseases?

Back 61

(1)Addison’s disease, (2)Chronic active hepatitis, (3)Giant cell arteritis, (4)Idiopathic thrombocytopenic purpura, (5)Postviral encephalomyelitis, (6)Thyroiditis [Graves; Hashimoto's], (7)Crohn’s disease, (8)Diabetes mellitus, (9)Hemolytic anemia, (10)Polymyositis/dermatomyositis, (11)Primary biliary cirrhosis, (12)Ulcerative colitis

Front 62

What are 13 examples of systemic autoimmune diseases?

Back 62

(1)Amyloidosis, (2)Mixed connective tissue disease, (3)Myasthenia gravis, (4)Progressive systemic sclerosis (scleroderma), (5)Reiter syndrome (reactive arthritis), (6)Sarcoidosis, (7)Systemic lupus erythematosus (SLE), (8)Ankylosing spondylitis, (9)Multiple sclerosis, (10)Polymyalgia rheumatica, (11)Psoriasis/Psoriatic arthritis, (12)Rheumatoid arthritis, (13)Sjogren’s syndrome

Front 63

What are two types of immunodeficiency diseases?

Back 63

(1)Congenital, (2)Secondary

Front 64

Describe a congenital immunodeficiency disease.

Back 64

IgA deficiency – most common – can not produceIgA (reduced resistance to intestinal infections). Severe combined immunodeficiency – lack T & B cells (needs to live in a bubble).

Front 65

Describe a secondary immunodeficiency disease.

Back 65

Acquired immunodeficiency syndrome. eg. Kaposi’s Sarcoma – malignant disease cause by Herpesvirus 8

Front 66

What is isoimmune phenomenon?

Back 66

Transplant rejection

Front 67

Why does isoimmune phenomenon occur?

Back 67

It occurs in response to transplantation because the body recognizes the donor tissue as nonself and attempts to destroy the tissue shortly after transplantation.

Front 68

What is a graft rejection?

Back 68

Incompatibility of cell surface antigens. Recipient’s immune system recognizes that the donor tissue’s HL! is different from their own.

Front 69

How is the immune system suppressed to reduce the risk of isoimmune phenomenon or graft rejection?

Back 69

Drug suppression of immune system with corticosteroids (eg prednisone, cortisone).