Alterations in Immunity - Patho Fall 2022
allergy
exaggerated immune response against environmental antigen
- Produces deleterious effects to environmental (exogenous) antigens
Autoimmunity
misdirected response against the host's own cells
-A disturbance in immunologic tolerance of self antigens
- CAN CAUSE autoimmune diseases
lupus erythematosus
an autoimmune disorder characterized by a red, scaly rash on the face and upper trunk
most common in women
Alloimmunity
directed against beneficial foreign tissue
immune system reaction against antigens on the tissues of other members of the same
species
EX: Think of transfusions and transplants
Transient neonatal alloimmunity: fetus expressing parental antigens not found in the
mother, mom sensitized against the fetus
EX: transplant rejection and transfusion reaction
Can also be called isoimmunity
Transfusion Reactions
Occur if mismatched blood is infused
Two major carbohydrate antigens:
Are A and B co-dominant.
Individuals have antibodies to the A and B antigens they lack.
Anti-A and anti-B antibody production are induced by similar antigens on naturally
occurring bacteria in the intestinal tract.
Antibodies are usually of the IgM class (isohemagglutinins).
O blood type: Is a universal donor.
AB blood type: Is a universal recipient
Ex: If patient A neg receives O pos blood, will see lysis & clumping of RBC's
transfusion reaction
•Is primarily expressed on erythrocytes.
•Rh-positive: Expresses the D antigen on the RhD protein.
•Rh-negative: Does not express the D antigen.
•Approximately 15% of North American white individuals are Rh-negative.
•Rh-negative individuals can make anti-D if exposed to Rh-positive erythrocytes
•Hemolytic disease of the newborn: Rh-negative mother gives birth to a Rh-positive
infant
immunodeficiency
insufficient response to protect the host
- all responses can be serious or life threatening
allergy, autoimmunity, alloimmunity
3 types of hypersensitivity reactions:
Hypersensitivity
allergy
exaggerated immune response against environmental antigen
- Produces deleterious effects to environmental (exogenous) antigens
Autoimmunity
misdirected response against the host's own cells
-A disturbance in immunologic tolerance of self antigens
- CAN CAUSE autoimmune diseases
lupus erythematosus
an autoimmune disorder characterized by a red, scaly rash on the face and upper trunk
most common in women
Alloimmunity
directed against beneficial foreign tissue
immune system reaction against antigens on the tissues of other members of the same
species
EX: Think of transfusions and transplants
Transient neonatal alloimmunity: fetus expressing parental antigens not found in the
mother, mom sensitized against the fetus
EX: transplant rejection and transfusion reaction
Can also be called isoimmunity
Transfusion Reactions
Occur if mismatched blood is infused
Two major carbohydrate antigens:
Are A and B co-dominant.
Individuals have antibodies to the A and B antigens they lack.
Anti-A and anti-B antibody production are induced by similar antigens on naturally
occurring bacteria in the intestinal tract.
Antibodies are usually of the IgM class (isohemagglutinins).
O blood type: Is a universal donor.
AB blood type: Is a universal recipient
Ex: If patient A neg receives O pos blood, will see lysis & clumping of RBC's
transfusion reaction
•Is primarily expressed on erythrocytes.
•Rh-positive: Expresses the D antigen on the RhD protein.
•Rh-negative: Does not express the D antigen.
•Approximately 15% of North American white individuals are Rh-negative.
•Rh-negative individuals can make anti-D if exposed to Rh-positive erythrocytes
•Hemolytic disease of the newborn: Rh-negative mother gives birth to a Rh-positive
infant
immunodeficiency
insufficient response to protect the host
- all responses can be serious or life threatening
allergy, autoimmunity, alloimmunity
3 types of hypersensitivity reactions:
Hypersensitivity
