[B] 1.14 Pathological aspects of immunology

Question 1

The 2 types of immune response

Answer 1

• Innate
• Adaptive

Question 2

Characteristics of innate immunity

Answer 2

• Nonspecific for antigens
• Immediate reaction
• No memory

Anatomical barriers, physiological properties, phagocytosis, complement system

Question 3

Characteristics of adaptive immunity

Answer 3

• Specific for antigens
• Slower reactions at first
• Memory → Fast reactions

Question 4

Adaptive immunity: Response types

Answer 4

• Cellular immunity (T-lymphocytes → IC pathogens)
• Humoral immunity (B-lymphocytes → EC pathogens)

Question 5

T-cells

Answer 5

Specific antigen binding molecule: T-cell receptor (TCR)

Only recognised antigen if bound to MHC

Question 6

B-cells

Answer 6

Specific antigen binding molecule: Cell membrane-bound Ig

Can recognise single antigen as well

Question 7

Phagocytic cells

Answer 7

• Macrophage
• Dendritic cells
• Granulocytes
  
  • Neutrophil
  • Eosinophil
  • Basophil

Question 8

Mononuclear phagocytic system (MPS)

Answer 8

During immunity, inflammation, tissue remodelling, repair

• In circulation: Monocyte
• In tissue: Histiocytes/Resident macrophage names
  
  • Kupffer cells in liver
  • Alveolar macrophage in lungs
• Phagocyting endogenous and exogenous pathogens

Question 9

Cytokines

Answer 9

• Messengers of the immune system
• Low molecular-weight soluble glycoprotein proteins
• Produced and act locally
• They direct the immune response

Question 10

Give the cells of adaptive immunity

Answer 10

T- and B-lymphocytes

Question 11

Give the 3 major groups of immune system disorders

Answer 11

• Hypersensitivity reactions
• Autoimmune diseases
• Immunodeficiencies

Question 12

If the immune response elicits an inflammatory response, that is not appropriate to the inciting antigen…

Answer 12

Severe tissue damage / Immune response directs to a self-antigen

Question 13

Hypersensitivity

Answer 13

The altered intensity of immune response, leading to pathologic lesions

• Types I - IV

Question 14

Type I hypersensitivity

Answer 14

Immediate

• Allergies
• Anaphylaxy

Question 15

Type II hypersensitivity

Answer 15

Cytotoxic

• Haemolytic anaemias

Question 16

Type III hypersensitivity

Answer 16

Immune complex

• Arthus reaction
• Systemic lupus erythematosus (SLE)
• Rheumatoid arthritis

Question 17

Type IV hypersensitivity

Answer 17

Delayed

• Tuberculin test
• Contact dermatitis

Question 18

Autoimmune diseases

Answer 18

Specific immune response to self-antigens

• Disorder of self-tolerance
• 2 mechanisms
  
  • Normal immune response to abnormal antigen
  • Abnormal immune response to normal antigen
• Result: Tissue damage & Inflammation
• Usually progressive
• Lymphoplasmocytic inflammation & fibration
• Organ specific autoimmune disease

Question 19

Immunodeficiency syndromes

Answer 19

• Immune system doesn’t respond to pathogens
• Either primary/secondary
• Can be genetic
• Affecting innate/adaptive immunity
• Doesn’t always cause health issues

Question 20

SCID

Answer 20

Severe combined immunodeficiency

• Humoral & cellular immunity
• Affects only: T-; B-cells; lymphoid stem cells
• Result: Failure to produce specific immunity
• Rarely found in bacterial infections

Question 21

Secondary immunodeficiencies

Answer 21

Many components can cause:

• Malnutrition
• Chronic diseases
• Tumours
• Ageing of the patient
• Viral infections, mycotoxins
• Immunosuppressive therapy
• Stress

Question 22

FIV

Answer 22

Feline Immunodeficiency Virus

• Progressive disorder of normal immunity
• ↓ CD4+ cells
• Alteration in CD4+/CD8+ ratio
• ↓ Antigen presentation
• ↓ migration & adhesion of neutrophils
• ↑ IgG (Hypergammaglobinaemia)
• Opportunistic infections

Question 23

Give examples of opportunistic infections which may be seen during FIV infection

Answer 23

• FeLV
• Calcicivirus
• Papillomavirus
• Mycoplasmas
• Toxoplasma gondii