Term
|
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
|
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? |
|
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? |
|
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
|
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? |
|
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? |
|
Definition
|
|
Term
| Why can Rhesus Factor cause medical problems in pregnant women? |
|
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? |
|
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? |
|
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
|
|
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. |
|
Definition
Result of hemolytic disease of the newborn (HDN).
Edema, fetal anemia, heart failure, death |
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Term
|
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
|
Definition
Higher concentration if the 2nd number is higher
(1:8 is less concentrated than 1:128) |
|
|
Term
| What are other consequences from Rh incompatibility besides hydrops fetalis? |
|
Definition
Brain damage from hyperbilirubinemia (from RBC destruction)
Life-threatening anemia |
|
|
Term
| What are the treatments for infants with hemolytic disease of the newborn? |
|
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? |
|
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
|
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
|
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. |
|
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
|
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
|
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
|
Definition
Receptors: IgM, CD5
Bind with: polysaccharides
Found in: mucosal tissue and peritoneum
Produce: mainly IgM, short-lived plasma cells |
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