Autoimmunity- Miller Flashcards
(103 cards)
What is autoimmunity ?
Immune response directed at self antigens
What is an autoimmune response ?
Any immune response that is directed at host tissues, The effectors of the autoimmune response are autoantibodies and autoimmune T cells
What is autoimmune disease ?
Chronic disease state that results from autoimmune responses
What is an antagonist ?
An antibody that binds to a cell surface receptor thereby preventing its function
What is an agonist ?
An Ab that binds to a cell surface receptor in a way that mimics the binding of the actual ligand to the receptor.
How are autoimmune diseases classified ?
By the immunological effector that is responsible for their function
What do autoimmune diseases arise through ?
Through the breakdown of the negative selection processes that remove self-reactive T cells and B cells from the Lymphocyte repertoire
Are autoimmune diseases ever mediated by IgE ?
No, autoimmune diseases are never mediated by IgE antibodies
What causes autoimmune hemolytic anemia ?
When IgG and IgM bind to the surface of erythrocytes
What happens when IgM and IgG bind to an erythrocyte ?
The complement cascade is activated and the RBC is destroyed
RBC depletion results in what condition ?
Anemia
how are RBC’s cleared from circulation?
Bound Ab and Cb3 mediate clearance of RBC’s from circulation by phagocytes in the spleen
How can you confirm Cb3 clearance of RBC’s from the blood ?
Direct Coomb’s Hemagglutination Test
What is neutropenia ?
A decreased number of neutrophils because they have been targeted for destruction by autoimmune responses directed at surface antigens of neutrophils
How can you treat neutropenia ?
Splenectomy will reduce the destruction of WBC’s
What is Type 2 schleroderma ?
Inflammatory destruction of vascuar endothelial cells of arterioles and smooth muscle cells; replacement with collagen and other fibrous materials.
**If can also affect the kidneys blood vessels, liver, and brain
What are the symptoms of Schleroderma ?
Localized or symmetrical skin thickening; hard smooth ivory colored areas of hardened skin
What is required to diagnose schleroderma
presence of anti-nuclear Abs, anti- topoisomerase Abs, and anti-centromere Abs (IgGs)
How do you treat Schleroderma ?
No real standard treatment but giving drugs that will increase blood flow to the extremities will help
What causes type 2 rheumatic fever ?
It is caused by antibodies that are produced during response to bacterial infection ( Group A streptococcus pyrogenes)
What is molecular mimicry ?
When bacterial specific antibodies cross react with heart tissue this is known as molecular mimicry
What is an example of molecular mimicry ?
Streptoccal cell - wall components are very similiar to determinants expressed in heart tissue. Bacteria specific antibodies can bind thesee similiar determinants and cause inflammation —> this can cause heart valve scarring and myocarditis
What is Type 2 Pemphigus Vulgaris ?
Autoimmune condition by IgG specific for 2 proteins resulting in loss of cohesion in heratinocytes in the epidermis
Pemphigus vulgaris is mediated by which antibody ?
IgG