Immunology - Autoimmunity + Immune Tolerance

Question 1

What is immune tolerance?

Answer 1

Physiological (to prevent faulty T/B cell self response)

Question 2

What happens in central and peripheral immune tolerance ?

Answer 2

Central = thymic tolerance
Peripheral = if T/B faulty cell evade central tolerance, they’re dealt with in 2^ lymphoid organs (eg. Spleen)

Question 3

What is autoimmunity?

Answer 3

Pathological response to itself
Faulty immune tolerance or molecular mimickery

Question 4

Organ specific autoimmunity - what do each of these disease affect?
T1DM
MS
Pernicious anaemia
Hashimotos
Graves
MG

Answer 4

Endocrine pancreas and B cells
Oligodendrocytes of CNS
Parietal cells of stomach
Anti TPO Ab ; thyroiditis
TSH-R
Ach - R Abs

Question 5

Non organ specific (generalized effect)
Affects DNA
Affects cell antigens

Answer 5

ANA in SLE

RBCs = autoimmune haemolytic anaemia
Platelets = immune thrombocytic purpura

Rheumatoid arthritis

Question 6

Immunodeficiency can be 2 things?

Answer 6

Inherited (defects in T cells) eg. IgA deficiency (north Europe), SCID (death in 2years)

Acquired (HIV)

Question 7

What is reduced in HIV?
What does this cause?
How does it increase susceptibility to disease?

Answer 7

Low CD4+ in HIV (these TH = required for cell mediated immunity, for both macrophage priming & B cell activity)

Therefore increased susceptibility to disease eg, CMV collitis (owl eyes), TB, pneumocystitis pneumonia, oral condida, EBV Berketts lymphoma

Question 8

B cell deficiency means?

Answer 8

Low plasma cells = low Abs

Question 9

Neutrophil+ macrophage deficiency means…

Answer 9

Required for phagocytosis + acute inflammation

Question 10

Complement deficiency
What are complements needed for?

Answer 10

Needed for innate immune killing of bacteria
Associated with SLE

Question 11

Hyposplenism means…

Answer 11

Lack of / decreased function of spleen ; RBC recycling + killing encapsulated bacteria - s.pneumo, N. meningitidis, H. Influenzae