Type IV Hypersensitivity

Question 1

Was first described in 1890 by Robert Koch. Sensitized T cells, rather than antibodies, play the major role in its manifestations

Answer 1

Type IV Hypersensitivity

Question 2

Type IV Hypersensitivity is also known as

Answer 2

Delayed hypersensitivity

Question 3

He observed that individuals infected with _ developed a localized inflammatory response after receiving intradermal injections of a filtrate from the organism

Answer 3

Mycobacterium tuberculosis (Mtb)

Question 4

Induce hematopoiesis of cells of the granulocyte-macrophage lineage and chemokines such as monocyte chemotactic protein (MCP-1/CCL2) recruit macrophages to the site.

Answer 4

IL3 and GM-CSF

Question 5

In the tissues, the monocytes differentiate into macrophages and are activated by

Answer 5

IFN-γ and TNF-β

Question 6

Chronic persistence of antigen leads to the development of organized clusters of cells are called

Answer 6

Granulomas

Question 7

Granulomas are consists of

Answer 7

Epithelioid-shaped and multinucleated fused macrophages with an infiltrate of lymphocytes or other WBCs

Question 8

Type of antigen that can be bacteria, fungi, parasites, or viruses.

Answer 8

Intracellular pathogens

Question 9

Examples of intracellular pathogens

Answer 9

Mycobacterium tuberculosis, Mycobacterium leprae, Pneumocystis carinii, Leishmania species, and herpes simplex virus

Question 10

Type of antigens that can come into direct contact with skin

Answer 10

Plants such as poison ivy and poison oak, metals such as nickel salts, and components of hair dyes and cosmetics

Question 11

The most common causes of contact dermatitis

Answer 11

Poison ivy, poison oak, and poison sumac

Question 12

This chemical is release in the plant sap and leaves

Answer 12

Urushiol

Question 13

Caused by contact with these plants affects millions of Americans every year.

Answer 13

Allergic dermatitis

Question 14

Other common compounds that produce allergic skin manifestations include

Answer 14

nickel; rubber; formaldehyde; hair dyes and fabric finishes; cosmetics; and medications applied to the skin, such as topical anesthetics, antiseptics, and antibiotics

Question 15

Cytokine production by the Th1 cells causes

Answer 15

Macrophages to accumulate and release cytokines and other substances that produce a local inflammatory response

Question 16

Produces a skin eruption characterized by erythema, swelling, and the formation of papules that appears from 6 hours to several days after the exposure

Answer 16

Contact dermatitis

Question 17

Is mediated predominantly by sensitized T lymphocytes that respond to inhaled allergens.

Answer 17

Hypersensitivity pneumonitis

Question 18

Other names for hypersensitivity pneumonitis

Answer 18

Farmer’s lung, bird breeder’s lung disease, and humidifier or air conditioner lung disease

Question 19

Bacterial and fungal spores, which individuals are exposed to from working with moldy hay, pigeon droppings, compost, moldy tobacco, infested flour, and moldy cheese

Answer 19

Causes hypersensitivity pneumonitis

Question 20

Used clinically to detect delayed hypersensitivity responses to a variety of antigens. The tests are based on a T-cell–mediated memory response.

Answer 20

Skin testing

Question 21

Used to determine allergen sensitivity in contact dermatitis, to assess exposure to Mycobacterium tuberculosis, and to evaluate competency of cell-mediated immune responses in patients with immune deficiency diseases.

Answer 21

Skin testing

Question 22

The gold standard in testing for contact dermatitis.

Answer 22

Patch test

Question 23

Redness with papules or tiny blisters is considered a

Answer 23

Positive test

Question 24

The tuberculin skin test that uses an M tuberculosis antigen extract prepared from a purified filtrate of the organism’s cell wall is called

Answer 24

Purified protein derivative (PPD)

Question 25

Induration reaction of 15 mm or more is considered

Answer 25

Positive test in individuals with no risk factors

Question 26

Reaction of 10 mm or greater is considered

Answer 26

Positive in recent immigrants of high prevalence countries

Question 27

An induration reaction of 5 mm or more is considered

Answer 27

Positive in persons who have HIV infection or other forms of immunosuppression

Question 28

Antigens typically used for testing are from sources to which individuals have been commonly exposed such as

Answer 28

C. albicans, tetanus toxoid, Streptococcus bacteria and fungal antigens like trichophyton and histoplasmin