Disorders of the Immune System
2.Differentiate between the etiology, clinical manifestations and pathophysiology ofselect disorders of the immune system.
a. Evaluate the etiology, clinical manifestations and pathophysiology of Type I, Type II, Type III, and Type IV hypersensitivities and describe the implications clinical practice.
Hypersensitivity
Etiology
Clinical
Manifestations
Pathophysiology
Type I
(IgE-Mediated
Hypersensitivity
Reactions)
Mediated by antigen-
specific IgE and the
products of tissue
mast cells. Most type
I reactions occur
against
environmental
antigens
Acute inflammatory
response
IgE has a relatively
short life span in the
blood b/c it rapidly
binds to very-high-
affinity Fc receptors
on the plasma
membranes of mast
cells. With further
exposure of antigen to
sensitized individual-
one molecule of
antigen may bind
simultaneously to 2
molecules of IgE-Fc
receptor on mast cell,
activating
intracellular signaling
pathways and mast
cell degranulation
Type II
(Tissue-Specific
Hypersensitivity
Reactions)
Characterized by a
specific cell or tissue
being the target on an
immune response.
“tissue specific
antigens”- are
Determined by which
tissue or organ
expresses the
particular antigen.
1. Cell can be
destroyed by antibody
and activate the
complement cascade
through the classical
pathway, resulting in



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- Fall '15
- david,mary
- cells, secondary immune response, Clinical Practice, Immune Response- IgM