Exam 3- Chapter 14 Hypersensitivity

Anaphylactic reactions are mediated by:

Mast cells

The precipitation of immune complexes in small blood vessels under the skin that occurs when antigen is injected in an animal with large amounts of circulating antibody describes which of the following?

Arthus Reaction

A hypersensitivity reaction characterized by the presence of IgG that reacts with soluble antigen best describes:

Type III

Which preformed mediator has a mode of action similar to that of histamine?

Heparin

The normal activity of a type I hypersensitivity response is protection primarily against which of the following?

Parasites

A positive direct antiglobulin test might indicate:

Autoimmune hemolytic anemia

Reactions to antigens in natural rubber (latex) can trigger:

Type I and Type IV

Contact dermatitis can be characterized by:

Langerhans cells acting as antigen-presenting cells

Type I hypersensitivity can be treated by injecting a specific recombinant humanized IgG called omalizumab. This antibody:

Binds to a heavy-chain domain on patient IgE, preventing the IgE from binding to mast cells

Anaphylaxis is characterized by which of the following?

Degranulation of mast cells

Type I hypersensitivity involves:

IgE binding to mast cells and eosinophils

Which immune mechanism is involved in contact dermatitis?

Sensitization of cytotoxic T cells

Hypersensitivities to poison ivy and nickel are:

macrophage and T-cell responses to a hapten.

All of the hypersensitivity responses have which of the following in common?

Asymptomatic sensitization phase

An exaggerated reaction directed against an antigen that is harmless is called:

Hypersensitivity

Immune injury resulting from the localization of immune complexes in blood vessels and tissues describes which hypersensitivity reaction?

Type III

T cell-dependent hypersensitivity occurs:

24-72 hours after exposure to antigen

A 10-year-old girl has been experiencing symptoms of nasal congestion, watery eyes, and sneezing for the past 2 years. Percutaneous testing revealed that she was allergic to a number of antigens, including ragweed, grasses, dust mites, and cat dander. Treatment with over-the-counter drugs did not do much to alleviate her symptoms, which seemed to worsen with time. Her doctor prescribed allergy immunotherapy, and her symptoms began to improve over the next year. This therapy is thought to work through the administration of:

gradually increasing doses of the allergen over time to induce production of blocking IgG4 antibodies.

An example of a condition that involves type III hypersensitivity is:

Rheumatoid arthritis

The principal difference between type II and type III hypersensitivity reactions is:

Whether an antigen is cellular or insoluble

The purified protein derivative reaction to determine exposure to tuberculosis is based on which of the following?

Sensitized T-cell response

A 5-year-old girl was rushed to the emergency department because she was having trouble breathing. She had been playing at the park when she fell down and her face and neck started to swell up. One of her friends thought that the girl might have been stung by a bee because a bee was flying around them, and shortly before the girl fell to the ground, she had screamed. The girl had a large red bump on her cheek. This girl likely has:

Type I hypersensitivity

To determine if a patient is allergic to peanuts, the best test to perform is:

Allergen specific IgE

A direct antiglobulin test is ordered on a patient sample. This test detects:

In vivo attachment of antibodies to red blood cells

Complement is responsible for tissue damage in which of the following reactions?

Type III hypersensitivity

A 37-year-old woman received two units of packed red blood cells following a surgical procedure. She had been transfused once before. Five days after surgery, she experienced a slight fever and some hemoglobin in her urine, indicating a delayed transfusion reaction. A direct antiglobulin test on a blood sample was positive. Which of the following statements best describes this reaction?

The patient's reaction was the result of an amnestic response.

Preformed mediators that are released during the activation phase of a type I hypersensitivity response include which of the following?

Histamine

Which of the following diseases is an example of a type II hypersensitivity?

Myasthenia Gravis

Compared with percutaneous (prick) tests, intradermal skin tests:

Are more sensitive

By gradually increasing doses of an allergen over time, allergy immunotherapy is thought to:

Induce Treg cell development

Which of the following occurs in hemolytic disease of the newborn?

The Rh- mother is exposed to Rh+ baby cells.

Which of the following is characteristic of autoimmune hemolytic anemia caused by cold agglutinins?

The IgM antibodies are specific to Ii blood groups

Reaction to poison ivy is which type of hypersensitivity?

IV

Which isotype of immunoglobulin is involved in a type I hypersensitivity?

IgE

Cold autoimmune hemolytic anemia is an example of which type of hypersensitivity?

Type II