Immunology

Question 1

Bordetella Pertussis

Answer 1

Whooping cough

Gram negative

Question 2

Primary Antibody Deficiency associated with sinusitis and ottis media

Answer 2

Selective IgA deficiency
Common variable immundeficieny
Specific antibody deficiency
X linked agammaglobulinemia

Question 3

Complement system disorders

Answer 3

Patients with laryngeal angioedema

Question 4

Severe congenital Neutropenia

Kostman Syndrome

Answer 4

Rare genetic disorder
Accumulation of precursor cells in bone marrow
Recurrent bacterial/fungal infections

Question 5

Leukocyte adhesion deficiency

Answer 5

Caused by defect in CD18 integrin gene

Failure of neutrophil adhesion and migration

Question 6

Chronic granulomatous disease

Answer 6

Deficiency of intracellular killing mechanisms of phagocytes - absent respiratory burst
Impaired killing of intracellular microorganisms

Question 7

How can adaptive immune system go wrong?

Answer 7

Defects in leukocyte development

Defects in leukocyte effector functions

Question 8

DiGeorge syndrome

Answer 8

Failure of production of CD4+ and CD8+ T cells
Developmental defect of pharyngeal pouch
Low set folded ears, high forehead, cleft pallet, small mouth and jaw
Hypocalcaemia
Oesophageal atresia

Question 9

X linked agammaglobulinaemia

Answer 9

Failure to produce b cells

Question 10

Hyper IgM syndrome

Answer 10

Severe reduction in serum IgG and IgA

Question 11

Clinical features of T cell deficiencies

Answer 11

Recurrent infections
Opportunistic infections
Malignancies at a young age
Autoimmune disease

Question 12

Clinical features of b cell deficiencies

Answer 12

Recurrent infections
Opportunist infections
Antibody mediated autoimmune disease

Question 13

Hypersensitivity

Answer 13

Immune response resulting in damage to bystander
Usually exaggeration of normal immune mechanism
Pathophysiological basis for chronic diseases (allergy and autoimmunity)

Question 14

Gel and Coomb’s Classification

Answer 14

1. Immediate Hypersensitivity
2. Direct cell effects
3. Immune Complex Mediated
4. Delayed Hypersensitivity

Question 15

Type 1

Answer 15

Immediate Hypersensitivity
Allergy
IgE mediated antibody response to external antigen

Question 16

2 stages of allergic disease

Answer 16

1. Sensitisation

2. Allergic

Question 17

Sensitisation stage

Answer 17

Mast cells and eosinophils express receptors for IgE antibody
First encounter allergen, B cells produce antigen specific IgE antibody
Allergen is cleared
Residual IgE antibodies bind to circulating mast cells

Question 18

Allergic stage

Answer 18

Re-encounter antigen
Allergen binds to IgE-coated mast cells and disrupt cell membrane
Release of vasoactive mediators (histamine)
Increased expression of pro-inflammatory cytokines and leukotrines

Question 19

Clinical features of allergic disease

Answer 19

Muscle spasm
Mucosal inflammation
Inflammatory Cell infiltrate

Question 20

Type 2

Answer 20

Direct Cell Effects
Cell surface antigens
Involve IgM or IgG
Normal adaptive immune response

Question 21

Goodpastures Syndrome

Answer 21

Type 2 Hypersensitivity
Autoimmune disease affecting lung and kidneys
Presence of auto-reactive antibodies to the alpha 3 chain of type IV collagen present in basement membranes of alveoli
From environmental insult

Question 22

Treatment of Goodpastures Syndrome

Answer 22

Corticosteroids
Plasmapheresis
STOP SMOKING

Question 23

Type 3

Answer 23

Immune Complex Mediated
Soluble Antigens
In presence of excess antigen, antibody binds forming small immune complexes
Trapped in small blood vessels, joints and glomeruli
Activation of complement system, opsonisation and neutrophils and macrophages

Question 24

Acute Hypersensitivity Pneumonitis

Answer 24

TYPE 3 HYPERSENSITIVTY
Inhaled antigens deposited in lungs
Stimulate antibody formation
Antibodies form immune complexes with antigen
Complement activation, inflammation etc
Leukocyte accumulation and inflammation within alveoli

Question 25

Type IV

Answer 25

Delayed Type Hypersensitivity | TB and Sarcoidosis

Question 26

Sarcoidosis

Answer 26

Multi-system granulomatous disease Small patches of red and swollen tissue to develop in organs Affects lungs and skin

Question 27

Management of sarcoidosis

Answer 27

Wait NSAIDS Systemic Corticosteroids

Question 28

Autoimmunity

Answer 28

Presence of immune responses against self-tissue/cells

Question 29

How does immune system deal with presence of auto-reactive T cells and B cells

Answer 29

Self tolerance mechanisms: 1. Deletion of self-reactive lymphocytes in primary lymphoid tissues (central tolerance) 2. Inactivation of self -reactive lymphocytes in peripheral tissues that escape central tolerane

Question 30

Regulatory T cells

Answer 30

Essential in suppressing hyper-reactive or auto-reactive T cells Via production of anti-inflammatory cytokines

Question 31

Pathogenesis of autoimmune disease

Answer 31

Genetic Susceptibility Breakdown of immune tolerance to self-antigens Autoimmune disease

Question 32

IPEX Syndrome

Answer 32

``` Monogenic Disorder (Single gene defect causes autoimmune disease) Symptoms = severe infections, excess etc Treatment = hematopoeietic stem cell transplant, Immunosuppressive drugs, parenteral nutrition ```

Question 33

Pathogenesis of IPEX syndrome

Answer 33

X linked Mutation in FOXP3 gene, needed for development of regulatory T cells IPEX = failure of peripheral tolerance mechanisms due to defective T cells

Question 34

HLA genes

Answer 34

Highly polymorphic

Question 35

Graves disease

Answer 35

Hyperthyroidism | Auto-antibodies generated that bind to thyroid stimulating hormone receptor

Question 36

Systemic Lupus Erythematosus

Answer 36

Type III Severe relapsing autoimmune disease Increased apoptosis, defective clearance of apoptotic material and dysregulation of neutrophil NETs

Question 37

Rheumatoid Arthritis

Answer 37

Type IV | Complication = inflamamtion in lungs and heart