Disorders of the Immune System Flashcards
3 types of disorders of the immune system
Hypersensitivity, autoimmune and immunodeficiency
Type I hypersensitivity is…
Immediate
Type II hypersensitivity is…
Anti-body mediated
Type III hypersensitivity is…
Immune-complex mediated (antibodies binding to antigens and activates complement)
Type IV hypersensitivity is…
Cell-mediated (T lymphocytes)
What is second, late-phase, type I hypersensitivity characterized by?
Infiltration of tissues with eosinophils, neutrophils, basophils, monocytes, lymphocytes and tissue destruction
Tissues commonly involved in type I hypersensitivity
Skin, resp tract, GI tract
Atopy
A genetically determined predisposition to develop localized hypersensitivity reactions to inhaled or ingested antigens
What are the 3 main mechanisms involved in type II hypersensitivity
Antibody-mediated cellular cytotoxicity, complement-mediated cellular cytotoxicity and antibody-mediate cellular dysfunction
Tissue damage in type III hypersensitivity is caused by…
Inflammatory reactions at the sites of deposition
Immune complexes formed are the most pathogenic in…
Slight antigen excess
What are two types of immune-complex mediate disease
Generalized (in circulation) and localized (in joints or skin)
Arthus reaction
Localized area of tissue necrosis resulting from acute immune complex vasculitis, there is an intense accumulation of neutrophils
The classic delayed type hypersensitivity IV is initiated by…
CD4 T cells (CD8 cells are also involved)
Autoimmune hemolytic anemia
Accelerated RBC destruction due to presence of antibodies attached to RBC membranes (type II hypersensitivity)
