First Aid, Chapter 2 Cells Involved in Immune Responses, Eosinophils

Question 1

What size are eosinophils? Describe their nuclei.

Answer 1

Have a bilobed nucleus and are 12–14 μm in size (Figure 2-9).

Question 2

What are contained in the primary granules of eosinophils?

Answer 2

Charcot-Leyden crystals.

Question 3

What are contained in the specific/secondary granules of eosinophils?

Answer 3

Specific/secondary granules contain preformed mediators that include major basic protein, eosinophil cationic protein, eosinophil peroxidase, and eosinophil-derived neurotoxin, which are all toxic to surrounding tissue and are released during cytolysis.

Question 4

What receptors do eosinophils express?

Answer 4

Express Fc receptors for immunoglobulins, β2-integrins (CD11a-cCD18), β1integrin (VLA-4), β4-integrin (α4β7), and PSGl-1.

Question 5

What protein can be used to detect eosinphils even when eosinophils are not seen on biopsy?

Answer 5

Major basic protein can be used to detect the recent presence of eosinophils in tissue, even when eosinophils cannot be seen on biopsy.

Question 6

Where do eosinophils mature?

Answer 6

bone marrow

Question 7

What cytokines stimulate differentiation, maturation, and activation of eosinophils?

Answer 7

GM-CSF, IL-3, and IL-5.

Question 8

What transcription factor is involved in eosinophil growth and differentiation?

Answer 8

GATA1

Question 9

What induces eosinophils to migrate to tissue?

Answer 9

Migrate to tissue in response to RANTES (CCL-5) and eotaxin (eotaxin-1, CCL-11; eotaxin-2, CCL-24).

Question 10

Where are eosinophils located?

Answer 10

o Most eosinophils reside in the tissue (lower GI tract, mammary gland, female reproductive tract, lymph tissue).
o 1–2% in peripheral blood.

Question 11

What is the half-life of eosinophils?

Answer 11

Half-life of approximately 18 hours.

o Levels vary throughout the day (diurnal variation).

Question 12

What is the function of eosinophils?

Answer 12

-Modulate immune response, fight helminthic infections, and has antitumor effects:
o Release of toxic granule proteins.
o Produce reactive oxygen species.
o Release leukotrienes and prostaglandins.
o Release cytokines, including IL-1, IL-2, IL-4, IL-5, IL-6, IL-8, IL-13, and TNF.
-Mammary gland development.
-Wound repair and tissue remodeling.

Question 13

What are causes of eosinophilia?

Answer 13

Causes for eosinophilia: NAACP 
Neoplasm 
Atopy 
Addison’s disease 
Collagen vascular disease Parasites

Question 14

What is the number 1 cause of marked eosinophilia in the US? In the world?

Answer 14

Drug reactions are the #1 cause of marked eosinophilia in the U.S., whereas parasitic infections are the #1 cause worldwide.

Question 15

What skin disease other than eczema can cause eosinophilia?

Answer 15

Pemphigoid

Question 16

What is Kimura’s disease?

Answer 16

Kimura disease is an inflammatory condition involving the subcutaneous tissue and lymph nodes of the head and neck, often with associated elevations in serum immunoglobulin E levels and eosinophilia.

Question 17

What lung diseases can cause eosinophilia?

Answer 17

o Allergic bronchopulmonary aspergillosis (ABPA)
o Loeffler’s syndrome
o Eosinophilic pneumonia
o Churg-Strauss vasculitis

Question 18

What infectious diseases cause eosinophilia?

Answer 18

o HIV (secondary to adrenal insufficiency, HIV medications, or HIV virus itself)
o Parasitic infections, especially those that invade tissue (strongyloidiasis)
o Isospora belli and Sarcocystis, but not other protozoa
o Chronic TB

Question 19

What suppresses eosinophilia?

Answer 19

• Most bacterial/viral infections (note the exceptions listed earlier, such as HIV).
• Fever
• Steroids