Chapter 16
hay fever
- allergic rhinitis - seasonal reaction to inhaled plant pollen or molds - chronic, year-round reaction to a wide spectrum of airborne allergens or inhalants
Eczema
- atopic dermatitis - sensitization occurs through ingestion, inhalation, and occasionally skin contact - begins in infancy with reddened, weeping, encrusted skin lesions - progresses in childhood and adult hood to dry, scaly, thickened skin
asthma
- characterized by episodes of impaired breathing due to severe bronchoconstriction - airways of asthmatics are exquisitely responsive to minute amounts of inhalant allergens, food or infectious agents
desensitization or hyposensitization
-70% of allergic patients benefit from controlled injections of specific antigens -prevents reactions between allergen, IgE, and mast cells -allergen preparations contain pure suspensions of plant antigens, venoms, dust mites, dander, and molds
Differences between the Arthus reaction and serum sickness
-Arthus reaction is a localized dermal injury -serum sickness is a systemic injury initiated by antigen-antibody complexes that circulate in the blood
bystander effect
-T-cell activation may incorrectly "turn on" B cells that react with self antigens -chemical compounds such as heavy metals may stimulate autoreactive T-cell populations
rheumatoid arthritis
-causes progressive, debilitating damage to joints in some patients, the lungs, skin, eyes, and nervous system are affected -autoantibodies form immune complexes that bind to the synovial membrane of the joints that activate phagocytes and stimulate the release of cytokines
forbidden clones
-clonal selection theory: the immune system of a fetus develops toleration by eradicating all self-reacting lymphocytes -some of these forbidden clones may survive and B or T cells can inappropriately attack tissues with self antigens
ABO antigen markers
-genetically determined -composed of glycoproteins -inherited as 2 of 3 alternative alleles: A, B, or O AA or AO genotype = type A BB or BO genotype = type B OO genotype = type O AB genotype = type AB
systemic lupus erythematosus (SLE)
-named for the characteristic butterfly- shaped rash drapes across the cheeks -patients produce autoantibodies against a great variety of organs and tissues or intracellular materials -predominant symptoms: kidney failure, blood abnormalities, lung inflammation, myocarditis, skin lesions
sequestered antigens
-some tissues are immunologically privileged, during embryonic growth -some of these antigens become exposed through infection, trauma, or deterioration -when they finally encounter immune cells, they are recognized as foreign, triggering a reaction to self antigen
Hygiene Hypothesis
-type I allergies develop due to lack of immune stimulus early in life -research has shown that children that grow up in rural areas with animals have lower rates of asthma and allergies -children growing up in larger families have less hay fever, asthma, and eczema
Type IV hypersensitivities primarily involves T-cells
-type IV diseases result when T-cells respond to antigens displayed on self tissues or transplanted cells -traditionally known as delayed hypersensitivity symptoms arise one to several days after second contact with an antigen
The blood type of the universal acceptor is type _____.
AB
Type II
Antibody-mediated; blood type incompatibilities
contact dermatitis
Caused by exposure to -resins in poison ivy or poison oak -haptens in household and personal articles -jewelry, cosmetics, elasticized undergarments -certain drugs Requires a sensitizing and a provocative dose
Type IV
Cell-mediated, cytotoxic; contact dermatitis, cell-graft rejection
In _________ syndrome, patients lack cell-mediated immunity.
DiGeorge
The thyroid gland is affected in _______ _____.
Graves' disease
The most common infection-induced immunodeficiency is ________.
HIV/AIDS
Type _____ hypersensitivity includes hay fever and asthma.
I
A reaction to a blood transfusion is a type _____ hypersensitivity.
II
Rheumatoid arthritis is a type _____ hypersensitivity.
III
An example of a type _____ is contact dermatitis.
IV
Type I
Immediate; hay fever, anaphylaxis
Type III
Immune Complex; rheumatoid arthritis, serum sickness
In multiple sclerosis, autoantibodies attack the ______ _____ surrounding nerve cells.
Myelin Sheath
The blood type of the universal donor is type _____.
O
Rh factor
Rh type results from a combination of two alleles: (Rh+) is dominant (Rh-) is recessive
Patients with _____ _____ ______ lack function of both B and T cells.
Severe Combined Immunodeficiencies
Type IV hypersensitivities are the result of the action of _______ (B/T) cells.
T cells
HIV/AIDS
T helper cells, monocytes, macrophages, and APCs are infected with HIV depletion of T helper cells and functional impairment of immune responses account for cancers and opportunistic infections associated with AIDS
autoantibodies
T-cells, and in some cases, both mount an abnormal attack against self antigens
Severe Combined Immundeficiencies (SCIDS)
The most serious and potentially lethal forms of immunodeficiency involve dysfunction in both lymphocyte systems some are due to the complete absence of lymphocyte stem cells in bone marrow others are attributed to dysfunction of B cells and T cells later in development most infants manifest symptoms within days after birth Swiss-type agammaglobulinemia thymic alymphoplasia =both result in extremely low numbers of all lymphocyte types and poorly developed humoral and cellular immunity
Cytotoxic T cells attack insulin-producing beta cells in the pancreas, causing ________.
Type I diabetes
The precipitating cause of autoimmune disease remains obscure -determined by genetics and gender -cases cluster in families and unaffected members develop autoantibodies for that disease
Women account for nearly 75% of cases of diagnosed autoimmune disease biological basis remains a mystery some autoimmunities linked to the X chromosome role of X-chromosome inactivation in the development of diseases serum from women with autoimmune diseases is often reactive with Barr bodies, a remnant of X-chromosome inactivation in nuclei
A number of B-cell immunodeficiencies are linked to the _____ chromosome.
X
anaphylaxis
a systemic, sometimes fatal reaction that involves airway obstruction and circulatory collapse first used to denote a reaction of animals injected with a foreign protein no response with first contact reinoculation with the same protein at a later time caused itching, sneezing, difficult breathing, prostration, and convulsions many died within a few minutes
agammablobulenemia
absence of gamma globulin very rare for Ig to be completely absent hypogammaglobulinemia is the term more often used by physicians T-cell function is normal
In myasthenia gravis, autoantibodies bind to receptors for _________.
acetylcholine
secondary immunodeficiency diseases
acquired after birth caused by natural or artificial agents
chemical mediators
act alone or in combination account for the tremendous scope of allergic symptoms targets: skin, upper respiratory tract, gastrointestinal tract, conjunctiva systemic targets: smooth muscle, mucous glands, nervous tissue changes in the activity of smooth muscle can alter blood flow, blood pressure, and respiration pain, anxiety, agitation, and lethargy are also attributable to the effects of mediators on the nervous system
antihistamines
active ingredients of most over-the-counter allergy-control drugs interfere with histamine activity by binding to histamine receptors on target organs side effects include drowsiness newer antihistamines do not have this side effect because they do not cross the blood-brain barrier
over-reactivity
allergy, hypersensitivity, and autoimmunity
autoimmune diseases
an individual develops hypersensitivity to him- or herself
allergens
antigens that do not noticeably affect non-allergic individuals
endogenous antigens
arising from self (autoimmunity)
aim of antiallergy medication
block the progress of the allergic response somewhere between IgE production and the appearance of symptoms
Adenosine Deaminase Deficiency (ADA)
caused by an autosomal recessive defect in the metabolism of adenosine lymphocytes develop but metabolic product builds up and abnormally and selectively destroys them
myasthenia gravis
caused by autoantibodies binding to the receptors for acetylcholine -required to transmit nerve impulses across the synaptic junction to the muscle damages the muscle cell membrane so severely that transmission is blocked and paralysis results first effects felt in the muscles of the eyes progresses to complete loss of skeletal function and death
Graves' Disease
caused by the attachment of autoantibodies to the thyroxin-secreting follicle cells of the thyroid gland causes overproduction of thyroid and symptoms of hyperthyroidism affects nearly every body system
atopy
chronic local allergy such as hay fever or asthma
Exposure to poison ivy can result in ________ ________.
contact dermatitis
Theories of the immunologic basis of desensitization
creation of IgG blocking antibodies
Serum sickness and the Arthus reaction are set apart from anaphylaxis because
depend on IgG, IgM, or IgA rather than IgE require large doses of antigen -anaphylaxis requires miniscule doses symptoms are delayed -hours to days
in vivo method
detects precise atopic or anaphylactic sensitivities skin is injected, scratched, or pricked with a small amount of pure allergen allergist maps the skin on the inner forearms or back 20 minutes after testing, skin is apprised for a wheal response skin tests for food allergies are unreliable
Anaphylaxis is treated with ________.
epineprine
allergy
exaggerated immune response that is manifested by inflammation
allograft
exchanges between genetically different individuals belonging to the same species
True/False: Different inflammatory cytokines have similar effects.
false
Which of the following are not atopic diseases? hay fever food allergies asthma eczema
food allergies
Blood types were first demonstrated by Karl Landsteiner in 1906
he found that the serum of one person could clump the red blood cells of another identified 4 distinct blood types: ABO blood groups
The fastest-acting allergic mediator is ________.
histamine
hyposensitivity diseases
immune function is incompletely developed, suppressed or destroyed
Secondary deficiencies in B and T cells are caused by
infection noninfectious metabolic disease chemotherapy radiation
A positive tuberculin test is an example of a(n) ________ allergy.
infectious
portal of entry for irritants
ingestant, inhalant, injectant, contactants
type I diabetes
insulin secreted by beta cells of the pancreas regulates glucose utilization molecular mimicry is implicated in sensitization of cytotoxic T cells against beta cells
organ specific
involve only one organ or tissue more than 80 recognized autoimmune diseases affect 5 - 8% of the US population
systemic
involves several major organs
A ________ is a type of graft from an identical twin.
isograft
Serum sickness and the Arthus reaction depend on ________ (large/small) amounts of antibodies.
large
molecular mimcry
leads the immune system to misidentify antigens microbial antigens display molecular determinants similar to normal human cells an infection could cause the formation of antibodies that cross-react with tissues rheumatic fever and psoriasis: result of bacterial infection type I diabetes and MS: possibly triggered by viral infection
Bone marrow or lymphoid organ cancers can cause malfunction of both humoral and cellular immunity
leukemia: massive numbers of cancer cells displace normal cells of the bone marrow and blood plasma cell tumors produce large amounts of nonfunctional antibodies thymus tumors cause severe T-cell deficiencies
The Arthus reaction is a ________ (systemic/localized) reaction, while serum sickness is a ________(systemic/localized) reaction.
localized, systemic.
mast cells
located virtually everywhere in body; a cell filled with basophil granules, found in numbers in connective tissue and releasing histamine and other substances during inflammatory and allergic reactions. allergen associated IgE
radioalergosorbant test
measures levels of IgE to specific allergens cannot be used for all allergens more tests have recently become available for food allergens
transfusion of wrong blood type
most severe reaction: massive hemolysis when donated red blood cells react with recipient antibody and trigger the complement cascade destruction of RBCs leads to systemic shock and kidney failure death is a common outcome
Hemolytic disease of the newborn can occur when the mother is Rh _____ and the fetus is Rh _____.
mother is Rh -, baby is Rh +
DiGeorge Syndrome
occurs due to errors in embryonic development or deletions in chromosome 22 characterized by lack of cell-mediated immunity children are susceptible to persistent infections by fungi, protozoa, and viruses vaccinations using live, attenuated microbes pose a danger normal childhood infections can be fatal
infectious allergy
occurs when a person sensitized by tuberculosis infection is injected with an extract of Mycobacterium tuberculosis tuberculin reaction inflammation at the injection site within 24 - 48 hours other diseases using this type of skin testing leprosy, syphilis, histoplasmosis, toxoplasmosis, candidiasis
Multiple Sclerosis (MS)
paralyzing neuromuscular disease associated with lesions in the myelin sheath T-cell and autoantibody induced damage compromises the capacity of neurons to send impulses result: muscular weakness and tremors, difficulties in speech, some degrees of paralysis
exogenous antigens
pollen, microbes, and foreign cells and proteins
primary immunodeficiency diseases
present at birth stem from genetic errors
______ ______ is an autoimmune disease that attacks the joints.
rheumatoid arthritis
To develop an allergy, first there is a ________ dose of allergen.
sensitizing
Immunopathology
study of disease states associated with overreactivity or underreactivity of the immune response
One of the most severe chronic autoimmune diseases is ______ ______ _____.
systemic lupus erythematosus
xenograft
tissue exchange between individuals of different species
isograft
tissue from an identical twin is used
autograft
tissue transplanted from one site on an individual's body to another site on his or her body
True/False: There are other RBC antigens besides A, B, and AB
true
True/False: Unlike anaphylaxis, serum sickness and the Arthus reaction do not depend on IgE antibodies.
true
type O blood lacks A and B antigens and will not be agglutinated by other blood types
universal donor
type AB blood lacks agglutinating antibodies
universal recipient
epinephrine
used by those prone to anaphylactic attacks injected or inhaled reverses constriction of airways slows the release of allergic mediators has a short half-life - more than one dose may be required buys the individual time to get to a hospital for continuing treatment
Describe the outcomes of transfusing the wrong type of blood
very bad hemolysis, shock, death
Implantation of a swine heart valve is an example of a(n) ________.
xenograft