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Chapter 7 
Immunity
Immune System 
 Responsible for body defenses 
 Nonspecific response (defense) 
• Examples: phagocytosis, inflammation 
...
Components of the Immune 
System 
 Lymphoid structures 
 Lymph nodes 
 Spleen 
 Tonsils 
 Intestinal lymphoid tissue ...
Components of the Immune 
System (Cont.) 
 Tissues—immune cell development 
 Bone marrow 
• Origination of all immune ce...
Structures of the Immune System 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •5
Elements of the Immune System 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •6 
 Antigens 
 S...
Antigens (Immunogens) 
 Usually exogenous substances 
 Cell surface antigens 
 Proteins 
 Polysaccharides 
 Glycoprot...
Cells 
 Macrophages 
 Initiation of immune response 
 Develop from monocytes 
 Part of the mononuclear phagocytotic sy...
Cells 
 Lymphocytes 
 T lymphocytes 
• From bone marrow stem cells 
• Further differentiation in thymus 
• Cell-mediated...
Cells (Cont.) 
 Lymphocytes 
 B lymphocytes 
• Responsible for production of antibodies 
• Humoral immunity 
• Mature in...
Types of Immunity 
 Humoral immunity: Antibodies are produced 
to protect the body. 
 Cell-mediated immunity (CMI): Lymp...
Development of Cellular and 
Humoral Immunities 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •...
Antibodies and Immunoglobulins 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •13 
 IgG 
 Most...
Antibodies and Immunoglobulins 
(Cont.) 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •14 
 Ig...
Review of the Major Components 
of the Immune System 
 Major components of the immune system and 
their function 
•Copyri...
Complement System 
 Activated during immune reactions with IgG 
or IgM 
 Group of inactive proteins circulating in blood...
Chemical Mediators 
 Involved in inflammation and immune 
reactions 
 Examples: histamine, interleukins 
 Variety of fu...
Diagnostic Tests 
 Titer (titre) 
 Measures levels of serum immunoglobulins 
 Indirect Coombs’ test 
 Detects Rh blood...
Immunity 
 Natural immunity 
 Species-specific 
 Innate immunity 
 Gene-specific 
 Related to ethnicity 
•Copyright ©...
Immunity (Cont.) 
 Primary response 
 First exposure to antigen 
 1 to 2 weeks before antibody titer reaches efficacy 
...
Primary and Secondary Immune 
Responses 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •21
Immunity 
 Active natural immunity 
 Natural exposure to antigen 
 Development of antibodies 
 Active artificial immun...
Immunity (Cont.) 
 Passive natural immunity 
 IgG transferred from mother to fetus: 
• Across placenta 
• Through breast...
Types of Acquired Immunity 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •24
Tissue and Organ Transplant 
Rejection 
 Hyperacute rejection 
 Immediately after transplantation 
 Acute rejection 
 ...
Immunosuppression 
 Reduction of immune response to prevent 
rejection 
 Commonly used drugs 
 Cyclosporine, azathiopri...
Hypersensitivity Reactions 
 Type I hypersensitivity—allergic reactions 
 Common 
• Caused by allergen 
• Skin rashes 
•...
Hypersensitivity Reactions 
(Cont.) 
 Type I hypersensitivity–allergic reactions 
(Cont.) 
 Hay fever: allergic rhinitis...
Type I Hypersensitivity 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •29
Anaphylaxis: Anaphylactic Shock 
 Severe, life-threatening 
 Systemic hypersensitivity reaction 
 Decreased blood press...
Anaphylaxis (Cont.) 
 Signs and symptoms 
 Generalized itching or tingling, especially in oral 
cavity 
 Coughing 
 Di...
Effects of Anaphylaxis 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •32
Signs and Symptoms of 
Anaphylaxis 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •33
Treatment for Anaphylaxis 
 Requires first aid response: 
 Administer EpiPen if available 
 Call 911 (many paramedics c...
Type II: Cytotoxic Hypersensitivity 
 Antigen is present on cell membrane 
 May be normal body component or exogenous 
...
Type II Hypersensitivity 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •36
Type III: Immune Complex 
Hypersensitivity 
 Antigen combines with antibody 
 Forms immune complexes, deposited in tissu...
Type III: Immune Complex 
Reaction 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •38
Type IV: Cell-Mediated or 
Delayed Hypersensitivity 
 Delayed response by sensitized T lymphocytes 
 Release of lymphoki...
Autoimmune Disorders 
 Development of antibodies against own cells 
or tissues 
 Autoantibodies are antibodies formed ag...
The Autoimmune Process 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •41
Type IV: Cell-Mediated Delayed 
Hypersensitivity 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. ...
Systemic Lupus 
Erythematosus (SLE) 
 Chronic inflammatory disease 
 Affects a number of organ systems 
 Characteristic...
Butterfly Rash Associated with SLE 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •44
SLE 
 Large number of circulating autoantibodies 
 Against DNA, platelets, erythrocytes 
 Formation of immune complexes...
SLE (Cont.) 
 Sings and symptoms vary because of organ 
involvement but commonly include: 
 Arthralgia, fatigue, malaise...
Common Manifestations of SLE 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •47
Immunodeficiency 
 Partial or total loss of one or more immune 
system components 
 Increased risk of infection and canc...
Immunodeficiency (Cont.) 
 Predisposition to the development of 
opportunistic infections 
 Caused by normal flora 
 Us...
Acquired Immunodeficiency 
Syndrome (AIDS) 
 AIDS—chronic infectious disease caused by 
the human immunodeficiency virus ...
AIDS (Cont.) 
 HIV-positive individual 
 Virus is known to be in the body. 
 No evidence of immunosuppression 
•Copyrig...
Stages in the Development 
of AIDS 
•Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •52
History of AIDS 
 First case recognized in 1979; HIV identified 
in 1984 
 Evidence of earlier sporadic cases 
 Now con...
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Chapter 007

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Ch 7

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Chapter 007

  1. 1. Chapter 7 Immunity
  2. 2. Immune System  Responsible for body defenses  Nonspecific response (defense) • Examples: phagocytosis, inflammation  Specific response (defense) • Production of specific antibodies against foreign substances •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •2
  3. 3. Components of the Immune System  Lymphoid structures  Lymph nodes  Spleen  Tonsils  Intestinal lymphoid tissue  Lymphatic circulation  Immune cells  Lymphocytes  Macrophages •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •3
  4. 4. Components of the Immune System (Cont.)  Tissues—immune cell development  Bone marrow • Origination of all immune cells •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •4  Thymus • Maturation of T lymphocytes
  5. 5. Structures of the Immune System •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •5
  6. 6. Elements of the Immune System •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •6  Antigens  Self • HLA proteins label cells of the individual. • Immune system ignores self cells.  Non-self • Immune system recognizes specific nonself antigens as foreign. • Development of a specific response to that particular antigen • Memory cells produced to respond quickly to antigen
  7. 7. Antigens (Immunogens)  Usually exogenous substances  Cell surface antigens  Proteins  Polysaccharides  Glycoproteins •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •7
  8. 8. Cells  Macrophages  Initiation of immune response  Develop from monocytes  Part of the mononuclear phagocytotic system  Engulf foreign material  Display antigens of foreign material  Secrete chemicals • Examples: monokines, interleukins  Present throughout the body •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •8
  9. 9. Cells  Lymphocytes  T lymphocytes • From bone marrow stem cells • Further differentiation in thymus • Cell-mediated immunity • Cytotoxic T killer cells • Helper T cells • Memory T cells •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •9
  10. 10. Cells (Cont.)  Lymphocytes  B lymphocytes • Responsible for production of antibodies • Humoral immunity • Mature in bone marrow  Proceed to spleen and lymphoid tissue • Plasma cells  Produce antibodies • B memory cells  Can quickly form clone of plasma cells •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •10
  11. 11. Types of Immunity  Humoral immunity: Antibodies are produced to protect the body.  Cell-mediated immunity (CMI): Lymphocytes are programmed to attack nonself cells to protect the body. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •11
  12. 12. Development of Cellular and Humoral Immunities •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •12
  13. 13. Antibodies and Immunoglobulins •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •13  IgG  Most common in blood  IgM  First to increase in immune response  IgA  In secretions • Tears • Saliva and mucous membranes • Colostrum
  14. 14. Antibodies and Immunoglobulins (Cont.) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •14  IgE  Allergic response  Causes release of histamine and other chemicals  Results in inflammation  IgD  Attached to B cells  Activates B cells
  15. 15. Review of the Major Components of the Immune System  Major components of the immune system and their function •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •15
  16. 16. Complement System  Activated during immune reactions with IgG or IgM  Group of inactive proteins circulating in blood  C1 to C9  Causes cell damage and further inflammation when activated •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •16
  17. 17. Chemical Mediators  Involved in inflammation and immune reactions  Examples: histamine, interleukins  Variety of functions  Signaling  Causing cellular damage •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •17
  18. 18. Diagnostic Tests  Titer (titre)  Measures levels of serum immunoglobulins  Indirect Coombs’ test  Detects Rh blood incompatibility •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •18  Elisa  Detects HIV antibodies  Used for a number of other diseases  MHC typing  Tissue matching before transplantation procedures
  19. 19. Immunity  Natural immunity  Species-specific  Innate immunity  Gene-specific  Related to ethnicity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •19
  20. 20. Immunity (Cont.)  Primary response  First exposure to antigen  1 to 2 weeks before antibody titer reaches efficacy  Secondary response  Repeat exposure to the same antigen  More rapid response, with efficacy in 1 to 3 days •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •20
  21. 21. Primary and Secondary Immune Responses •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •21
  22. 22. Immunity  Active natural immunity  Natural exposure to antigen  Development of antibodies  Active artificial immunity  Antigen purposefully introduced to body  Stimulation of antibody production  Immunization  Booster immunization •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •22
  23. 23. Immunity (Cont.)  Passive natural immunity  IgG transferred from mother to fetus: • Across placenta • Through breast milk  Protection of infant for the first few months of life or until weaned  Passive artificial immunity  Injection of antibodies  Short-term protection •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •23
  24. 24. Types of Acquired Immunity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •24
  25. 25. Tissue and Organ Transplant Rejection  Hyperacute rejection  Immediately after transplantation  Acute rejection  Develops after several weeks  Chronic, late rejection  Occurs after months or years •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •25
  26. 26. Immunosuppression  Reduction of immune response to prevent rejection  Commonly used drugs  Cyclosporine, azathioprine, prednisone  High risk of infection  Caused by immunosuppression  Opportunistic organisms •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •26
  27. 27. Hypersensitivity Reactions  Type I hypersensitivity—allergic reactions  Common • Caused by allergen • Skin rashes • Hay fever  Causative mechanism • Exposure to allergen • Development of IgEs • Mast cells  Complications • Anaphylaxis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •27
  28. 28. Hypersensitivity Reactions (Cont.)  Type I hypersensitivity–allergic reactions (Cont.)  Hay fever: allergic rhinitis • Nasal mucosa  Food allergies • Digestive tract mucosa  Atopic dermatitis/eczema •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •28 • Skin  Asthma • Bronchial mucosa
  29. 29. Type I Hypersensitivity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •29
  30. 30. Anaphylaxis: Anaphylactic Shock  Severe, life-threatening  Systemic hypersensitivity reaction  Decreased blood pressure caused by release of histamine  Airway obstruction  Severe hypoxia  Can be caused by:  Latex materials  Insect stings  Nuts or shellfish; various drugs •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •30
  31. 31. Anaphylaxis (Cont.)  Signs and symptoms  Generalized itching or tingling, especially in oral cavity  Coughing  Difficulty breathing  Feeling of weakness  Dizziness or fainting  Sense of fear and panic  Edema around eyes, lips, tongue, hands, feet  Hives  Collapse with loss of consciousness •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •31
  32. 32. Effects of Anaphylaxis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •32
  33. 33. Signs and Symptoms of Anaphylaxis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •33
  34. 34. Treatment for Anaphylaxis  Requires first aid response:  Administer EpiPen if available  Call 911 (many paramedics can start drug treatment and oxygen)  Treatment in emergency department:  Epinephrine  Glucocorticoids  Antihistamines  Oxygen  Stabilize BP •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •34
  35. 35. Type II: Cytotoxic Hypersensitivity  Antigen is present on cell membrane  May be normal body component or exogenous  Circulating IgGs react with antigen  Destruction by phagocytosis or cytolytic enzymes •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •35  Example  Response to incompatible blood transfusion
  36. 36. Type II Hypersensitivity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •36
  37. 37. Type III: Immune Complex Hypersensitivity  Antigen combines with antibody  Forms immune complexes, deposited in tissue  Activation of complement system  Process causes inflammation and tissue destruction  Examples:  Glomerulonephritis  Rheumatoid arthritis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •37
  38. 38. Type III: Immune Complex Reaction •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •38
  39. 39. Type IV: Cell-Mediated or Delayed Hypersensitivity  Delayed response by sensitized T lymphocytes  Release of lymphokines  Inflammatory response  Destruction of the antigen  Examples:  Tuberculin test  Contact dermatitis  Allergic skin rash •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •39
  40. 40. Autoimmune Disorders  Development of antibodies against own cells or tissues  Autoantibodies are antibodies formed against self-antigens—loss of self-tolerance.  Disorder can affect single organs or tissues or can be generalized.  Examples:  Hashimoto thyroiditis, systemic lupus erythematosus, rheumatic fever, myasthenia gravis, scleroderma, pernicious anemia •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •40
  41. 41. The Autoimmune Process •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •41
  42. 42. Type IV: Cell-Mediated Delayed Hypersensitivity •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •42
  43. 43. Systemic Lupus Erythematosus (SLE)  Chronic inflammatory disease  Affects a number of organ systems  Characteristic facial rash—“butterfly rash”  Affects primarily young women  Incidence is higher in African Americans, Asians, Hispanics, Native Americans •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •43
  44. 44. Butterfly Rash Associated with SLE •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •44
  45. 45. SLE  Large number of circulating autoantibodies  Against DNA, platelets, erythrocytes  Formation of immune complexes  Deposited into tissues  Inflammation and necrosis  Vasculitis develops in many organs.  Impairs blood supply to the tissues •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •45
  46. 46. SLE (Cont.)  Sings and symptoms vary because of organ involvement but commonly include:  Arthralgia, fatigue, malaise  Cardiovascular problems  Polyuria  Diagnostic test  Serum antibodies, LE cells, other blood work  Treatment  Usually treated by a rheumatologist  Prednisone (glucocorticoid)  Nonsteroidal anti-inflammatory drugs •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •46
  47. 47. Common Manifestations of SLE •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •47
  48. 48. Immunodeficiency  Partial or total loss of one or more immune system components  Increased risk of infection and cancer  Primary deficiencies  Basic developmental failure somewhere in the system  Secondary or acquired immunodeficiencies  Loss of the immune response from specific causes  Can occur at any time during the life span • Infections, splenectomy, malnutrition, liver disease, immunosuppressant drugs, radiation, chemotherapy (cancer) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •48
  49. 49. Immunodeficiency (Cont.)  Predisposition to the development of opportunistic infections  Caused by normal flora  Usually difficult to treat because of immunodeficiency  Prophylactic antimicrobial drugs may be used prior to invasive procedures. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •49
  50. 50. Acquired Immunodeficiency Syndrome (AIDS)  AIDS—chronic infectious disease caused by the human immunodeficiency virus (HIV)  HIV destroys helper T cells—CD4 lymphocytes  Loss of immune response  Increased susceptibility to secondary infections and cancer  Prolonged latent period  Development may be suppressed by antivirals •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •50
  51. 51. AIDS (Cont.)  HIV-positive individual  Virus is known to be in the body.  No evidence of immunosuppression •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •51  AIDS  Marked clinical symptoms, multiple complications  Individual often identified as HIV-positive before development of AIDS  Current therapies start if HIV infection is diagnosed in the early stages.
  52. 52. Stages in the Development of AIDS •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •52
  53. 53. History of AIDS  First case recognized in 1979; HIV identified in 1984  Evidence of earlier sporadic cases  Now considered to be a pandemic  Occurs in men and women  2006, CDC: 1 million cases in North America  2007, UN: 33 million cases globally; 22 million of those in sub-Saharan Africa •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •53

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