Immunology 9 and Review - Autoimmune, meningitis

Question 1

Specific or systemic autoimmunity

Answer 1

Depends on the original auto-antigen targeted. If it is only found in one place (ie thyroid) it will be specific. If it is found more widely (ie widespread or large areas) or if immune complexes found in blood it can be systemic

Question 2

Immunological escalation

Answer 2

Autoimmunity starts specific to one auto-antigen but it can then start targeting other similar or associated auto-antigens. Can be hard to identify what Ag was first

Question 3

A few examples of organ specific autoimmune diseases

Answer 3

Type 1 diabetes (Tdth cells target pancreas ß cells); Addison’s disease (autoAB target adrenal Ag); ITP (autoAB vs platelets)

Question 4

AutoAB to cell surface receptors - examples

Answer 4

Grave’s disease (autoAB bind to TSH receptors, and actually stimulate Thyroid to produce TH - also stimulates hypertrophy and hyperplasia); myasthenia gravis (autoAB to Ach receptor, block Ach, so muscle is inactive)

Question 5

A few examples of systemic autoimmune diseases

Answer 5

Ankylosing spondylitis (Immune complexes and Tdth target vertebrae); MS (Tdth and Tc cells attack brain/white matter); Rheumatoid arthritis (AutoAB, Tdth vs connective tissue, IgG); Psoriasis (Tdth and Th17 target skin)

Question 6

Do autoimmune diseases run in families? What is the possible factor?

Answer 6

They sort of do. We think it is the MHCs. They act as a barcode and are associated with elevated risk.

Question 7

Ankylosing spondylitis mechanism

Answer 7

Marker is the HLA-B27 gene. Much higher risk of developing the condition.

Question 8

Autoimmune diseases and types of hypersensitivity

Answer 8

Type 1: nothing. Type 2: active in rejection of transfusion, AI hemolytic anemia, Goodpasture’s syndrome. Type 3: Systemic lupus erythematosus. Type 4: Tissue graft rejection, MS (?), Rheumatoid arthritis, Diabetes

Question 9

Treatment of autoimmune diseases

Answer 9

Usually a biologic (large protein, typically monoclonal AB). Can block Th1 cytokines (ie TNFa) or block co-stimulation (ie B7-CD28). Suffixes -mab is AB, -cept is soluble receptor for co-stimulator. Expensive!

Question 10

Consequence of biologics?

Answer 10

If you block TNFa, you Tdth cells can’t react as well to contain some infections ie in granuloma (TB, etc). Some may also cause autoimmune diseases to boot.

Question 11

impetigo

Answer 11

characterized by honey brown crust on skin. treat with topical antibiotics (not steroids)

Question 12

prick test

Answer 12

drops of an allergen on skin, then prick skin so it gets through barrier (for large molecules) and can react. Type 1 reaction

Question 13

patch test

Answer 13

patches on back with solutions in the patches. Just on surface, these are small molecules and can diffuse into skin no problem.

Question 14

Asplenic concerns

Answer 14

More prone to encapsulated bacteria (S pneumoniae, N meningitidis) hemopholis influenzae)

Question 15

Vaccines from Jessica case

Answer 15

polysaccharide vaccines. Not bad, but the conjugated vaccines are better, then get polysaccharide booster

Question 16

What antimicrobials were started on Jessica upon admission?

Answer 16

Vancomycin (gram -ve) and ceftriaxone (gram +ve). Get coverage quick for sepsis.

Question 17

meningitis symptom patient gets lumbar puncture. What results could be there for bacteria?

Answer 17

Gram -ve cocci = N meningitidis. Gram +ve cocci = S pneumoniae