Chapter 12: Disorders of the Immune System Flashcards
primary immunodeficiency:
something you are born with
secondary immunodeficiency:
something you get later on in life
examples of secondary immunodeficiency states:
malnutrition, infection, neoplastic disease, immunosuppressive therapy
results of alterations in the immune system:
immunodeficency states, allergic or hypersensitivty reactions, transplantation rejection, autoimmune disorders
four major categories of immune mechanisms:
- humoral or antibody mediated immunity
- cell-mediated immunity
- complement system
- phagocytosis
hypersensitivity is a
altered immune response to an antigen
hypersensitivity results in
disease/damage to host
deletrerious effects of hypersensitvity to environmental antigens
allergy
body doesn’t recognize itself, thinks that it is foreign and attacks its own cells
autoimmunity
immune reaction to tissues of another individual
alloimmunity
describe some of the roles of mast cells:
plays a big role in IgE sensitivity, part of connective tissue, allergic diseases, anaphylaxis, autoimmune disorders/acute or chronic inflammation, wound healing, innate response for clearing bacteria and viruses
IgE mediated is commonly called
allergic reactions
IgE mediated has local aka atopic reactions such as
hay fever, food allergies, bronchial asthma, hives
IgE mediated:
on first contact with allergen, it is called a
sensitizing dose
IgE mediated
subsequent exposure with the same allergen and it binds
provocative dose
Atopy
Local or Genetic
Allergy
Anaphylaxis
most dangerous form of Type I
Hypersensitivity - life-threatening phenomenon; Very rapid Systemic release of histamine
and other inflammatory mediators from
IgE-coated mast cells, Must have been previously “sensitized” or
exposed to a specific antigen.
Type II Hypersensitivity is
Antibody Dependent
Antibody Dependent is
Cytotoxic; IgG or IgM attack antigens on cell
surfaces (antibodies bind to
antigens on cell surface
examples of IgG or IgM attack on antigens-
Transfusion reactions, Rh
Disease
Autoimmune Diseases such as Multiple Sclerosis
Drug reactions
Rh disease can lead to
stillbirth or jaundice
in cytotoxic hypersensitivity- If incompatible blood types are mixed
agglutination occurs
and complement is activated
transfusion reactions in type II
Antibodies against blood group antigens
ABO system
ABO system
Two major carbohydrate antigens
-A and B (codominant)
-Individuals have naturally occurring antibodies to
the A and B antigens they lack
-Anti-A and anti-B antibody production is induced
by similar antigens on naturally occurring bacteria
in the intestinal tract
-Antibodies are usually of the IgM class
-O blood type (universal donor)
-AB blood type (universal recipient)
Immune Complex
Hypersensitivity is caused by
Antigen-Antibody Aggregates
immune Complex
Hypersensitivity develops when
antibody combines with
antigen and form aggregates that
accumulate in the blood vessels or tissue
surface. These Immune complexes become
trapped in tissues & incite a damaging
inflammatory response (can circulate or stay
in one area)
Immune Complex deposits cause
Inflammation by activating complement sys
Serum sickness
(systemic reaction) occurs when
IgG is produced against residual proteins in a
serum
Most often caused by Antibiotics, foods, and
Insect Venom (ex; antitoxin aka tetanus)
Serum sickness can cause
kidney damage
symptoms of type I anaphylactic
hypersensitivity: hives and swelling in the
face, neck and joints
Direct Cell-Mediated Cytotoxicity
Mediated by T lymphocytes NOT
antibodies; delayed allergic response
delayed allergic response
can be skin
response to allergens – tuberculin skin test,
contact dermatitis from plants, metals,
cosmetics but also includes Graft Rejection
and some autoimmune diseases
autoimmune disease
Normal ability to determine self from non-
self (aka Self Tolerance) is disrupted -
hyperactive immune system
autoimmune diseases are determined
through evidence of
autoimmune reaction and ruling out any
other causes (secondary to another
condition)
autoimmune disease examples
Systemic lupus erythematosus (SLE) Grave’s Disease Multiple Sclerosis Hashimoto thyroiditis
Immunodeficiency diseases
Components of the immune response
system are absent. Deficiencies involve
B and T cells, phagocytes, and
complement
primary immunodeficiency
genetically based congenital lack of B
-cell and/or T cell activity
Secondary (acquired) immune
deficiency
due to damage
after birth (infections, drugs,
radiation) AIDS
Human Immunodeficiency Virus
attaches to and penetrates host T cells (CD4+
aka Helper T or Th cell)
The virus continues to take over and kill T h cells
- Monitor CD4+ counts
B cells
what do B cells do in HIV
produce antibodies discover the
virus and begin to make antibodies but…without
the direction of the helper T cells, there is no
direction so B Cells are ineffective
where is the main reservoir of HIV
Lymphatic tissue (spleen, lymph nodes, tonsils/adenoids)
AIDS
does not kill - the infections associated with depressed/suppressed immune system function is what actually kills
