Term
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Definition
Agonistic antibody that stimulates the TSH receptor Results in overproduction of thyroid hormone |
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Term
Hashimoto's Lymphocytic Thyroiditis |
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Definition
3-4% (High) Prevalence Antibodies against thyroglobulin and thyroid peroxidase (TPO) block thyroid hormone production HYPOthyroidism Inflammation, Maybe also CTL-mediated damage |
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Term
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Definition
5-8% Incidence within 6 mo. post-partum Not as common as Hashimoto's Complement-fixing anti-Thyroid Peroxidase antibodies Results in Hypothyroidism |
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Term
Describe the thyroid in Hashimoto's Disease |
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Definition
Many infiltrated lymphocytes Difficult to see thyroid follicles Enlarged lymphatics expand thyroid size = goiter Germinal centers form in the lymphatics - B cell proliferation - produce IgG Thyroid Gland "becomes a lymph node" Probably a type II and IV mixed reaction |
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Term
What antibody class recognizes carbohydrate antigens? |
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Definition
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Term
What type of antigen is T cell independent? What does this mean? |
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Definition
Carbohydrate antigens (If polyvalent) can activate B cell without T cell help Ex = ABO blood groups |
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Term
What acutely mediates a type IV Hypersensitivity reaction? |
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Definition
CTLs, Inflammatory Cytokines |
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Term
What is the type IV hypersensitivity called the "delayed type"? |
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Definition
Happens 24-48 hours after skin exposure Time required for T cells to accumulate and mediate the reaction |
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Term
How long does it take for a type III arthus reaction to happen? |
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Definition
8-12 hours for immune complexes to form in situ |
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Term
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Definition
the chemical structure that forms (non-covalent) bonds with the antigen receptor |
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Term
What limits the maximum size of an epitope? |
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Definition
Size of the antigen binding site of a variable region 6 amino acids OR 6 hexoses |
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Term
How is an antigen receptor different from a ligand receptor? |
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Definition
An antigen receptor has a variable binding site that can bind a wide variety of different antigens. |
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Term
What is the size of the smallest molecule recognized by an antibody? How do we take advantage of this in medicine? |
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Definition
Smallest thing = 1 benzene/1hexose Put in very small synthetic molecules that won't be recognized |
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Term
What antibody class recognizes protein antigens? |
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Definition
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Term
Why can Rhesus Factor cause medical problems in pregnant women? |
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Definition
As a (t cell dependent) protein antigen, it is recognized by IgG, which can cross the placental barrier. |
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Term
What kind of cell induces class switching in B cells? |
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Definition
T cells (working with T-dependent protein antigens) |
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Term
Why do we have natural antibodies against the different blood group types that we don't have? |
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Definition
The ABO antigens resemble sugars found in common enteric bacteria. We make the natural IgM antibodies against the enteric bacteria. |
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Term
What is best practice during blood transfusions? |
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Definition
1. Use packed RBCs, not whole blood 2. Test for compatibility before transfusion |
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Term
What happens if you transfuse O whole blood into a B patient? |
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Definition
Anti-A antibodies in the recipient can't bind to donor RBCs, so there is no reaction. |
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Term
What percentage of the population is Rh-negative? |
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Definition
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Term
Where is rhesus (Rh) antigen found? |
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Definition
a protein in an ion channel on the RBC |
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Term
How do Rh-negative mothers develop anti-Rh IgG? |
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Definition
Rh-negative mothers are exposed to Rh+ fetus, especially during birth |
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Term
Describe Hemolytic Disease of the Newborn. |
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Definition
Rh-negative mother transfer her anti Rh-IgG via FcRn to the subsequent fetus, this will attack the Rh+ fetus. |
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Term
Describe hydrops fetalis. |
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Definition
Result of hemolytic disease of the newborn (HDN). Edema, fetal anemia, heart failure, death |
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Term
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Definition
Passive immunity blocks active immunity Give IM injection of IgG anti-Rh to FIRST TIME MOMS Give @ 26 weeks and within 72 hours of birth Coats/lyses fetal cells in maternal circulation and blocks immune response |
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Term
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Definition
Higher concentration if the 2nd number is higher (1:8 is less concentrated than 1:128) |
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Term
What are other consequences from Rh incompatibility besides hydrops fetalis? |
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Definition
Brain damage from hyperbilirubinemia (from RBC destruction) Life-threatening anemia |
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Term
What are the treatments for infants with hemolytic disease of the newborn? |
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Definition
1. Fluorescent irradiation of jaundiced infants. 2. Intrauterine or post-partum transfusion. |
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Term
What is the rationale behind the amount of RhoGam given to first time mothers? |
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Definition
Give 300 ug of RhoGam (anti-Rh antigen antibodies) This is enough to neutralize 30 mL of fetal serum that might get into maternal blood. |
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Term
Why does RhoGam fail 0.1% of the time? |
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Definition
Because more than 30 mL of fetal serum has gotten into the maternal circulation. |
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Term
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Definition
Are the RBCs coated with a particular antibody? Combine RBCs with an antibody to a certain type of antibody - see if it agglutinates? |
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Term
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Definition
Does the serum in question contain antibodies that could react with the test RBCs? |
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Term
Does free immunoglobulin bind to Fc receptors? |
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Definition
No. antibodies must have bound antigen before they can bind Fc receptors on macrophages, etc. |
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Term
Name 2 ways of activating the macrophage to lead to destruction of a bacterium. |
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Definition
1. Aggregate the immunoglobulin on the bacterial surface to allow binding to Fc receptors. 2. Conformational change in immunoglobulin on binding to antigen may expose Fc-binding site. |
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Term
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Definition
Receptors: IgD, IgM Bind with: protein antigen + helper T cells Undergo a germinal center reaction Produce: isotype-switched, high-affinity antibodies, long-lived plasma cells (IgG, IgA, IgE) |
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Term
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Definition
Receptors: IgM Location: marginal zones of splenic white pulp, respond to blood-bourne polysacharides Bind with: polysaccharides, lipids, etc. Produce: mainly IgM and short lived plasma cells |
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Term
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Definition
Receptors: IgM, CD5 Bind with: polysaccharides Found in: mucosal tissue and peritoneum Produce: mainly IgM, short-lived plasma cells |
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