Flashcards in Immunopathology Type 2, Autoimmunity Deck (20)
Describe the molecular and cellular details of the immunologic mechanisms by which tissue damage occurs in a Type II ("cytotoxic antibody") reaction.
When you activate the immune system, you activate complement and that lyses cells. So it's complement mediated damage to tissues. Also neutrophil mediated tissue destruction
Give an example of a Type II mechanism disease of muscle
Myasthenia Gravis- autoimmune response against the acetylcholine receptors
Treatment: immunosuppression, neostigmine-
related drugs to increase the effectiveness of residual Ach, and IVIG
Describe the tests which would allow you to make the diagnosis of Goodpasture's Syndrome
Linear kidney immunofluorescence, glomerulonephritis,
Kidney biopsy, if there is IgG in the biopsy, the anti IgG will stain the kidney red where teh human antibody is (direct test)
Using a normal kidney, you can wash the normal kidney with the patient's blood and observe the following immunofluoresences
Distinguish between the "lumpy-bumpy" and "linear" immunofluorescent patterns in terms of the most probable immunopathologies they represent.
Linear- Antibodies specifically against kidney BM (goodpastures) (Type II)
Lumpy-Bumpy- Antibodies trapped in the glomerulus that is a result of them being unable to be filtered by the kidney. Immune complex deposition pattern (Type III)
Given patient's serum, fluorescent antibody to human immunoglobulins, and slices of normal kidney, describe how you could tell if the patient's glomerulonephritis was due to Goodpasture's Disease or SLE.
For SLE, the glomerulonephritis is actually type III, so it's lumpy bumpy, because it's just deposition of antibodies in the kidney chronically.
Describe how antibody-mediated tissue damage could result from the innocent bystander phenomenon
If there is an antibody response against a foreign antigen that is attached to self tissue.
Identify "Rheumatoid Factor" and describe its molecular nature.
Marker of Rheumatoid arthritis. (T cell mediated attacking of the lining of joints)
can be detected by adding the patient’s serum to microscopic beads that are coated with normal human IgG. RF makes the beads agglutinate; ►it is IgM anti-IgG!
Name the condition in which antibody stimulates rather than inhibits or harms its target cell.
In Grave's disease, antibody stimulates thyroid receptors, acting as ligand (TSH). However, the normal physiological controls to reduce thyroid signalling is not applicable, so you have hyperthyroidism
Discuss how the Aire gene is involved in preventing autoimmune disease.
AIRE genes express various molecular patterns resemble self antigen, so that in t cell maturation and selection, we can avoid self reaction.
Give an example of a Type II mechanism disease of Kidneys
Goodpasture- Type IV Collagen in Basement membrane in the glomerulus, leading to destruction of
Give an example of a Type II mechanism disease of the heart
Agonist to Beta adenergic receptors on the heart (Innapropriate tachycardia)
Rheumatic Heart Disease (Strep infection leads to cross reactivity to heart tissue endothelial lining/laminin)
Dressler Syndrome- Post heart attack antibodies to pericardial or myocardial antigens
Give an example of a Type II mechanism disease of Red Cells
Autoimmune Hemolytic Anemia
Give an example of a Type II mechanism disease of Platelets
Give an example of a Type II mechanism disease of the lung
Goodpasture- Type IV Collagen in Basement membrane, leading to pulmonary hemorrhage
Give an example of a Type II mechanism disease of the Thyroid
Graves (hyperthyroidism) and Hashimotos (Hypothyroidism)
Give an example of a Type II mechanism disease of Pancreatic islets
Type I Diabetes
Describe how antibody-mediated tissue damage could result from cross reaction of a foreign antigen to self
THink rheumatic fever, where following a strep infection (or other infections), it cross reacts with heart tissue causing Type IV
Describe how antibody-mediated tissue damage could result from coupling self antigen with a foreign antigenic "carrier,"
If a self b lymphocyte isn't killed, it normally won't be an issue because you won't get the t response necessary to mount an immune response. However, if somehow a foreign antigen is coupled with that same self antigen, THAT can mount a response after presentation of the coupled epitope, because the foreign epitope is presented but the self Ig is produced.
Describe how antibody-mediated tissue damage could result from exposure of a sequestered antigen
So there are some tissue in our body that isn't normally seen by developing t cells (think Dresslers), so following tissue injury, the body is suddenly exposed to this "foreign" antigen and we get a type II response