Chapter 17

true or false: myasthenia gravis results from production of NK cells that target and destroy cells that have acetylcholine receptors.

False

Which cells are involved in delayed-type hypersensitivity?

T cells

An allograft is _____

Transplanted tissue or organ from a non-identical donor of the same species.

Contact dermatitis is a type IV hypersensitivity that is due to _____

due to the response of effector T cells to small molecules that penetrate intact sin and act as sensitizing agents.

Latex, a product of the rubber tree, contains a plant ___ that readily induces sensitization, leading to type I or type IV hypersensitivities.

protein

Degranulation of mast cells and basophils ____

releases inflammatory mediators from the cells and depends on cross-linking of surface bound IgE by an allergen.

In order for sensitization to occur, the following events must take place in this order:

1- exposure to the allergen molecules, usually across a mucous membrane or through the skin. 2 stimulation of an antibody-based immune response of the IgM type 3- class switching of the antibody produced by the plasma cells to the IgE type 4- binding of the antibody Fc region to the surface of basophils and mast cells via their Fc receptors.

A swollen, red, painful injection site, characterized by localized deposition of inflammation-inducing immune complexes, is a ______

Arthus reaction

True or false: Type IV hypersensitivities involve antibodies.

False

The idea behind ____ (hyposensitization) therapy is to cause the immune system to produce IgG antibodies that protect against the allergen, facilitating its removal its removal before it can attach to bound IgE on mast cells or basophils.

Desensitization

True or false: A person develops anti-A and anti-B antibodies only after exposure to type A or type B blood.

False

True or false: If major histocompatibility complex (MHC) and blood group typing doesn't match a donor's tissue with a recipient's, the graft should never be performed because the risk of rejection is too high.

False

True or false: In a very well-matched transplant, anti-rejection drugs are not required afterwards.

False

True or false: If major histocompatibility complex (MHC) and blood group typing doesn't match a donor's tissue with a recipient's, the graft should never be performed because the risk of rejection is too high

False, the risk is increased but some will work.

true or false: Transfusion reactions and serum sickness are caused by the same mechanism.

False- transfusion reactions occur when antibodies bind to donor RBCs, activating complement systems and forming MACs. Serum sickness results from immune complex formation and the inflammation that can result.

By using an IgG molecule that will specifically bind to the ___ region of IgE molecules, the drug omalizumab can limit allergic responses by preventing IgE molecules from binding to the surface of basophils and mast cells.

Fc

As a prelude to an allergic response, the Fc portion of ___ antibody molecules bind to receptors on either mast cells or basophils.

IgE

The first anti-Rh IgM antibodies produced during sensitization of an Rh-negative mother will not attack the cells of the first baby of that woman because

IgM antibodies cannot cross the placenta

People who have the D antigen on the RBCs are referred to as ____ while those lacking the antigen are ____.

Rh-positive; Rh-negative

statement about contact dermatitis

a person experiences contact dermatitis on expousre to the allergen after sensitization has occurred.

Treatments for autoimmune disease typically involve

administering anti-inflammatory medications and administering immunosuppressant medications

How can a pregnant Rh-negative woman be sensitized to Rh antigens?

after a miscarriage, as her blood is exposed to some of the Rh-positive fetal blood from the placenta during childbirth and induced abortion.

In a transfusion reaction, donor red blood cells are bound by ___ in the recipient's blood. This results in activation of the complement cascade, leading to the formation of MACs and RBC lysis.

antibodies

RhoGAM is a medication that consists of anti-RH specific ___ which will bind any stray Rh-positive cells

antibodies

An allergen is an _______

antigen that is usually a harmless environmental substance that induces an allergic reaction in some sensitized individuals

Induction of oral tolerance takes place when ____

antigens are introduced through the oral route, allowing the system to "learn" how to tolerate them over time.

The causes of autoimmune disease _______

are not clear and involve multiple factors.

Substances that can induce contact dermatitis would share which of the following characteristics?

are small organic or inorganic molecules that can penetrate intact skin

In a transfusion reaction, the ___ red blood cells are destroyed when __

donor's ; the recipient's natural antibodies bind to the donor RBC's, leading to their destruction.

During an ____ attack, release of inflammatory mediators in the lower respiratory tract, induced by secondary exposure to an allergen, causes constriction of bronchial tubes and interference with breathing.

asthma

Antibodies that are produced after exposure to self-antigens are referred to as ______

autoantibodies

Systemic lupus erythematosus (SLE) is caused by production of ___ that bind to molecules found in the nuclei of self cells, causing a variety of symptoms including rashes, joint pain, and swelling, and in sever cases, damage to kidneys or other organs.

autoantibodies

When the immune system fails to eliminate or silence developing lymphocytes that would respond to and attack normal body tissues, ____

autoimmunity occurs.

autoimmune disease with its sign and symptoms Type I diabetes Rheumatoid arthritis Myasthenia gravis Graves' disease Lupus

betes- loss of insulin production arthritis- joints and tissues myasthenia gravis- loss of muscle contraction graves' disease- loss of thyroid hormone production lupus- symptoms vary, but often include rashes.

Antihistamine medications, such as diphenhydramine (Benadryl), are often used to relieve symptoms of allergy by _____

blocking binding sites for histamine

Because they interfere with cytotoxic T cells, immunosuppressive drugs used long-term for minimization of rejection post-transplant can make a patient more susceptible to _____ and infections

cancer

Sensitization is essentially an immune response to an allergen. After this immune response has begun, what is the critical step that must take place in order for sensitization to occur?

class-switching from IgM to the IgE isotype.

A second Rh-positive baby carried by a sensitized Rh-negative mother will lead to antibody-mediated attack of the new fetal red blood cells because ____

class-switching of the antibodies to the IgG isotype has occurred, and IgG can readily cross the placenta

Disseminated intravascular coagulation (DIC) occurs when ____

clots form in small blood vessels, leading to organ failure

In type II hypersensitivity, tissues are damaged either by activated _____ proteins or by antibody-dependent cellular _____ (ADCC)

complement and cytotoxicity.

Because the type II hypersensitivity responses destroy cells, they are called ___

cytotoxic hypersensitivities.

Type 1 diabetes mellitus occurs when ____

destuction of pancreatic b cells by cytotoxic T cells.

A shot of ____ is an effective treatment for systemic anaphylaxis because it is a vasoconstricting drug, countering the vasodilation effects of the allergen.

epinephrine

Signs and symptoms of type I diabetes mellitus include ___

fatigue, extreme hunger, and weight loss, increased thirst, and urination

The purpose of a bone marrow transplant is to replace ____

hematopoietic stem cells

Ingested food allergens can cause an outbreak of ____ in the skin because they are absorbed into the bloodstream, where they travel to the skin and cross-link IgE on basophils and mast cells there.

hives

Omalizumab belongs to a class of drugs known as rhuMabs (recombinant ________ monoclonal antibodies)

humanized

An exaggerated immune response that injures tissue is called _____ and can be categorized into one of four groups according to the mechanisms and timing of the response

hypersensitivity

Large ____ complexes are quickly removed from the body because they are easy targets for phagocytosis. However, smaller immune complexes may not be quickly destroyed. They may remain in circulation or at their sites of formation in the tissues, potentially causing type III hypersensitivities.

immune

In a bone marrow transplant, a person's bone marrow and ____ are destroyed using radiation and ___, before new, healthy bone marrow is transplanted.

immune system cells; chemotherapy

Graves' disease occurs when autoantibodies inappropriately activate thyroid- stimulating hormone receptors on the thyroid gland. This can result in ____

increased metabolic rate, fatigue, and irritability and bulging eyes and enlarged thyroid gland.

Cellular mechanisms of self tissue damage in rheumatoid arthritis result from T-cell infiltration into joints, leading to _____

induction of inflammation by cytokines released from T cells.

People receiving insulin injections and those receiving pancreatic transplant treatments must all receive indefinite treatment. This is because ____

insulin must be injected because it can't be produced any longer by the pancreatic cells and pancreatic cell transplants must be accompanied by anti-rejection drugs indefinitely.

An example of a xenograft would be ___

involve tissues from non-human animals induce strong immune responses. EX- pig heart into a human heart

Matching major histocompatibility complex (MHC) and blood group types prior to transplantation _____

is performed to minimize risk of rejection when time allows.

RhoGAM contains anti-Rh antibodies and is injected into Rh-negative women carrying an Rh-positive fetus during pregnancy and shortly after delivery. This helps prevent hemolytic disease of the newborn because

it binds to RH-positive RBCs that may have entered the maternal blood, preventing an initial anti-RH antibody response.

Rheumatoid arthritis is a systemic disease in which connective tissues, particularly those within ___ are destroyed.

joints

Systemic anaphylaxis may

lead to heart failure, be fatal in a few minutes, and lead by suffocation

The skin and the respiratory tract are two of the most common sites where ___ allergic reactions occur.

localized

The arthus reaction, a swollen, red, painful area at the site of an injection, is a prime example of ____

localized immune complex reaction

Hemolytic disease of the newborn is generally not life-threatening prior to birth because ____

maternal enzymes eliminate the toxic products of red blood cell destruction

Contact hypersensitivities result when ___

memory cells cause a damaging cell-mediated response

The contents of the granules of basophils and mast cells that are released when surface IgE are cross-linked by an allergen are effective at helping to eliminate

parasitic worms

All of the following are linked with type ! allergic reaction

pollen, pet dander, or mold. peanut. seafood. venom or penicillin NOT poison ivy.

An example of a systemic immune complex disease is ___ sickness, a complication that can occur after passive immunization with animal serum.

serum

Two of the most common sites for localized allergic reactions are the ____

skin and respiratory tract

Symptoms of hay fever include ____

sneezing, runny nose, teary eyes resulting from exposure of a sensitized person to inhaled antigen; an IgE mediated allergic reaction.

______ anaphylaxis can occur when antigen enters the bloodstream and spreads throughout the body.

systemic

True or false: Injection of insulin in type I diabetes mellitus patients is an example of replacement therapy.

true

Wheal and flare is a term used to describe ____

typical localized allergic reaction found in the skin