Abnormal Immune Response Flashcards
What categories of immunodeficiency are there?
Primary and secondary
Name the 5 types of immunodeficiency
T-Cell disorders B-cell disorders T and B cell disorders Complement disorders Disorders of phagocytosis
Treatment of immunodeficiency
Gamma globulin (antibody) replacement therapy or bone marrow or thymus transplant
Hypersensitivity is?
Over exaggerated or inappropriate immune response
What types of hypersensitivity are there?
Allergy, cytotoxic, immune complex, and delayed
What are the characteristics of allergy HS?
Most common type of hypersensitivity, due to allergens and is a rapid response
Primary immunodeficiency is?
Congenital or genetic, resulting from a development failure
Secondary immunodeficiency is?
Acquired post-natal from infection, cancer treatment or immunosuppressive drugs
Cytotoxic HS
Antibodies mistarget surface antigens on self cells. Antigen bearing cells are destroyed by complement, phagocytosis and inflammation
What is an example of cytotoxic HS?
Incompatible blood transfusion
Immune complex HS characteristics
antibody-antigen complex (immune complex) is deposited in endothelium of capillaries and when machrophages kill IC holes form in endothelium
Why is the immune complex not broken down?
Because of size or because it is insoluble
Delayed HS
Macrophage ingests microbe and presents it to T cell which becomes sensitized, then cytotoxic T cells are produced which destroy the the self-cell leading to inflammation and tissue damage
What is an example of delayed HS
TB test
What are the types of shock?
Cardiogenic, hypovolemic, obstructive, and distributive
What is anaphylactic shock?
Severe allergic reaction
What is immunodeficiency?
Partial or complete loss of the immune response
Allergy HS is divided into what two categories
Sensitization and re-exposure
Sensitization phase of allergy HS
Exposure to allergen leads to a helper T cell stimulating B cells which release IgE molecules that attach to mast cell, making the mast cell sensitized
How many times does sensitization occur?
Only once
Re-Exposure phase of allergy HS
The antigen binds directly onto IgE on mast cell which leads to mediator release and inflammation
Anaphylactic shock patho physiology
Since mast cells were previously sensitized and flowing throughout the whole body, the allergic reaction is systemic when the antigen binds to the mast cell
What occurs in the body during anaphylactic shock?
Excessive systemic vasodilation, increase permeability, decrease vascular resistance leading to hypoperfusion, and edema systemically
What is a bronchospasm?
When mediators bind to smooth muscle in the respiratory tract and the muscle constricts and stays constricted
Characteristics of septic shock are what?
Systemic vasodilation, hypoperfusion and hypotension due to infection and many mediators being released
What does septic shock result in?
Multiple organ dysfunction
What occurs during autoimmunity?
Antibodies target self antigens
Why does autoimmunity occur?
Because there is a loss of self-tolerance and confusion occurs between self and non-self
What three ways can self-tolerance be lost?
Abnormal T cell activity, molecular mimicry, or exposure of previously masked self-antigens
What is an example of abnormal T cell activity resulting in autoimmunity?
Cytotoxic T cells are not suppressed once foreign microbe has been destroyed
What is an example of molecular mimicry resulting in autoimmunity?
Self cell has very similar epitope as microbe leading to confusion of antibody and it accidentally bonds to self cell
What is an example of exposure of previously masked self antigens resulting in autoimmunity?
Proteins that were kept internally rather than externally, but during injury the internal proteins moved to the surface of the cell to compensate for damage leading to the antibodies not recognizing these unmarked self cells and thinking they’re foreign
