Hypersensitivies II Flashcards
What antibodies are associated with Type 2 reactions?
IgG and IgM
How fast does a Type 2 reaction occur?
within hours IF prior sensitized
Type 2- clinical syndrome?
Cytolysis of antibody coated cells leads to Anemia or Thrombocytopenia or Neutropenia
What are the two key mechanisms of Type 2 reactions?
Antibody-mediated complement activation & phagocytosis of opsonized healthy cells
When does Type 2 hypersensitivity occur?
When antibodies and complement destroy normal/healthy cells
What is another name for Type 2 hypersensitivity?
cytotoxic hypersensitivity
What is hemolytic disease of a newborn?
Mothers may become sensitized to their fetus during pregnancy and make antibodies against fetal RBCs. These antibodies may cause destruction of newborn RBCs if ingested in colostrum.
If a calf ingests colostrum containing anti-MHC antibodies induced by vaccination of the mother, ____ _____ can occur in the calf.
lethal pancytopenia
How do blood cells become targets in Type 2 reactions?
drugs bind to blood cells making them targets
What are the effector mechanisms of antibody-mediated disease?
Injury caused by anti-tissue antibody (complement/Fc receptor)
Immune complex-mediated tissue injury
Opsonization and phagocytosis
Abnormal physiologic responses without cell/tissue injury
Which antibodies can cause disease by binding to their target antigens in cells and tissues?
IgM and IgG
NOT IgE!!
The antibodies that cause disease are most often considered what?
autoantibodies against self antigens
How can anti-streptoccal antibodies cause rheumatic fever?
These antibodies can cross-react with heart tissue which induce rhematic fever
Rheumatic fever is a ______ disease that can lead to _____ heart failure.
inflammatory; acute
Antibodies can form immune complexes that can deposit where?
in the blood vessels and organs
Immune complex deposition in the blood vessels causes _______.
vasculitis
How can immune complex deposition in the kidney cause renal failure?
Anti-streptococcal antibodies deposit in kidney glomeruli cause post-streptococcal glomerulonephritis that can lead to renal failure
Short story –> nephrons are clugged so the kidney cannot function properly
C3a receptors are important factors in opsonization effector mechanism of antibody-mediated diseases. True or false?
False AF.
Its C3b, not C3a.
How does the opsonization and phagocytosis effector mechanism work?
Promotion of cell destruction through antibody binding
Interference of normal cell function
What are the complement byproducts associated with complement and Fc receptor mediated inflammation?
C5a and C3a
Do not get this confused with C3b in opsonization mechanism.
How is injury caused by an anti-tissue antibody?
Antibodies specific for tissue antigens may deposit in tissues and cause injury by inducing local inflammation.
How is local inflammation induced by anti-tissue antigen mechanism?
Complement and Fc receptor mediated recruitment and activation of inflammatory cells.
Antibodies against Ach receptor cause _______.
paralysis (myasthenia gravis)
Anti-TSH antibodies induce _______.
Hyperthyroidism (Graves disease)
Autoimmune hemolytic anemia - mechanism of disease and clinical manifestations?
mechanism: opsonization and phagocytosis of erythrocytes
outcome: hemolysis, anemia
Autoimmune thrombocytopenic purpura - mechanism of disease and clinical manifestations?
opsonization and phagocytosis of platelets
bleeding (lack of blood coagulation)
Graves Disease - mechanism of disease and clinical manifestations?
Antibody-mediated stimulation of TSH receptors
hyperthyroidism
Myasthenia gravis - mechanism of disease and clinical manifestations?
Antibody inhibits Ach binding down-modulated receptors
muscle weakness, paralysis
Rheumatic fever - mechanism of disease and clinical manifestations?
inflammation, macrophage activation
myocarditis, arthritis
Graves Pemphigus vulgaris - mechanism of disease and clinical manifestations?
antibody-mediated activation of proteases, disruption of intracellular adhesions
skin vesicles (bullae), your mother fucking skin comes off
What are the causes of type 2 reactions?
Secondary to drug treatment (hapten-carrier complex)
Secondary to infectious agents
primary IMHA due to autoimmune process
Allo-immune reactions are caused by what?
incompatibility between donor and recipient (blood transfusion reactions)
What defines blood types?
erythrocyte glycoproteins (antigens)
Anti-glycoprotwin antibodies react with ____ antigens.
RBC
Blood type A produces which plasma antibody?
anti-B
Blood type B produces which plasma antibody?
anti-A (IgG and IgM)
Blood type AB produces which plasma antibody?
None.
What blood type is a universal recipient?
AB
What blood type is a universal donor of packed red blood cells?
type O
Which blood type does not express any antigens?
type O
Which blood type anti-A and anti-B plasma antibodies?
type O
Which species does not have type O?
cat
What blood type is rare in cats?
AB antigens
What blood type in cats is dominant in the USA?
A
What blood type in cats is dominant in Europe?
B
On a card blood test agglutination of RBCs indicates a positive test. True or false?
True
How many blood types do cattle have?
11
How many blood types do horses have?
7
How many blood types do pigs have?
16
What is another name for Hemolytic Disease of Newborn?
Neonatal isoerythrolysis
What species are affected by neonatal isoerythrolysis?
humans, horses, cattles, dogs, cats
