AUTO - B. AUTOIMMUNE DISEASES-COVERED

Question 1

what causes autoimmune disease

Answer 1

• antibodies against ‘self’ proteins
• tissue damage
• genetic factors
• precipitated by:
  pregnancy
  infection
  diet
  environment

Question 2

development of autoimmune diseases

Answer 2

• autoantigens in everyone
• but not everyone develops autoantibodies to these
• and not everyone that have autoantibodies develops autoimmune disease
• self-tolerance prevents auto antigens activating IS
• autoimmune disease: tolerance lost, attack of ‘self’ by IS

Question 3

Hashimoto’s disease

Answer 3

• hypothyroidism (decreased thyroid hormone)
• antibodies against thyroid gland, so decreased thyroxine produced
• fatigue
• enlarged thyroid
• weight gain
• cold
• women 7x more likely to get
• age (later in life)
• heredity
• Treatment = Levothyroxine

Question 4

Grave’s disease

Answer 4

• autoantibodies (agonist at receptor) stimulate thyroid to produce thyroxine
• hyperthyroidism
• Treatment = inhibit thyroid hormone production

Question 5

Type 1 diabetes

Answer 5

• mix of autoantibodies found
  antibodies to glutamic acid decarboxylase
  antibodies against proteins on B-cells
  insulin antibodies
• Treatment = Insulin

Question 6

Systemic Lupus Erythematosus

Answer 6

• Anti-dsDNA antibodies in 80% patients
• joint pain
• extreme tiredness
• skin rashes, esp exposed to sun
• severe: inflam of lungs, heart, kidneys

Question 7

Crohn’s and UC

Answer 7

• autoimmune?
• changes in colonic bacteria?
• UC - autoantibodies found in 80% patients
• Crohn’s - antibodies against microbes (colonic bacteria)
• Treatment = dampening down immune system, similar drugs used which treat RA

Question 8

APCs

Answer 8

• present antigen to T-cell
  macrophages
  B-cells
  dendritic cells

Question 9

Macrophages

Answer 9

• engulf and digest pathogen
• presents antigen on surface of cell, recognised by other immune cells

aka:
- alveolar cells
- Kupffer cells
- microglial cells
- osteoclasts
- mesangial cells

Question 10

B-cells

Answer 10

• produced in bone marrow
• mature in spleen
• generate antibodies to specific antigens
• some develop into memory cells - secondary response

Question 11

Dendritic cells

Answer 11

• activate T-cells by promoting clonal expansion and differentiation
  B-cells = B-cell for that particular AB
  T-cells = cytotoxic, T-helper
• also ingest invading organisms through phagocytosis

Question 12

T-cells

Answer 12

• T cell receptors which recognise specific antigens (APCs)
• Helper T-cells have TCRs and CD4 receptors that bind to APC
• once bound, helper T-cells release cytokines to stimulate defence against that antigen, exacerbates immune response
• cytotoxic T-cell have TCRs and CD8 receptors. TCRs recognise virally infected cells and kill them

Question 13

Natural killer cells

Answer 13

• target infected cells and cancer cells
• monoclonal antibodies can target NK/T-cells to cancer cells which hide from IS

Question 14

Granulocytes

Answer 14

• WBCs that contain granules: neutrophils, basophils, eosinophils
• formed in bone marrow
• circulate bloodstream
• neutrophils: phagocytose
• basophils: release histamine
• eosinophils: release cytokines (LTs and TNF-alpha)

Question 15

Cytokines

Answer 15

Interleukins 1-25
Cysteinyl leukotrienes
TNF-alpha: pro-inflam, chemotactic, increases smooth muscle proliferation

Question 16

Chemokines

Answer 16

• chemotactic cytokines

Question 17

TNF-alpha

Answer 17

• major cytokine
• blocking action of it inhibits inflammation
• MAbs will bind to TNF-alpha

Question 18

IL-6

Answer 18

• role in inflam
• proliferation of immune cells
• COVID-19 increased IL-6 and TNF-alpha = cytokine storm