Leukopenia and Leukocytosis

Question 1

What is a normal white blood cell count?

Answer 1

5-10 K/uL

Question 2

What is it called when there is a low WBC count (

Answer 2

Leukopenia

Question 3

What is it called when there is a high WBC count (>10K)?

Answer 3

Leukocytosis

Question 4

What are the 2 most common causes of neutropenia?

Answer 4

Drug toxicity

Severe infection

Question 5

What is the mechanism of for neutropenia seen with drug toxicity?

Answer 5

Damage to stem cells→ decreased production of WBCs, especially neutrophils

Question 6

What is the mechanism for neutropenia see with severe infections?

Answer 6

Increased number of neutrophils in the tissues leads to decreased circulating neutrophils

Question 7

What is the treatment for neutropenia?

Answer 7

GM-CSF or G-CSF—boost granulocyte production

Question 8

What are the 4 major causes of lymphopenia?

Answer 8

Immunodeficiency
High cortisol state
Autoimmune destruction
Whole body radiation

Question 9

How does a high cortisol state induce lymphopenia?

Answer 9

Causes apoptosis of lymphocytes

Question 10

What cells are highly sensitive to radiation and cause a specific type of leukopenia?

Answer 10

Lymphocytes—causing lymphopenia

Question 11

What are the 3 major causes of neutrophilic leukocytosis?

Answer 11

Bacterial infection
Tissue necrosis
High cortisol state

Question 12

How does a bacterial infection or tissue necrosis cause neutrophilic leukocytosis?

Answer 12

They induce the release of marginated pool and bone marrow neutrophils

Question 13

What is a left shift of neutrophils seen with a bacterial infection or with tissue necrosis?

Answer 13

Immature neutrophils are released from the bone marrow causing the left shift

Question 14

What characterizes the immature neutrophils that are released from the bone marrow during a bacterial infection or tissue necrosis?

Answer 14

Decreased Fc receptor CD 16

Question 15

How does a high cortisol state cause neutrophilic leukocytosis?

Answer 15

A high cortisol state impairs leukocyte adhesion—causing a release of marginated pool of neutrophils

Question 16

What are 2 causes of monocytosis?

Answer 16

Chronic inflammatory state

Malignancy

Question 17

What are 3 causes of Eosinophilia?

Answer 17

Allergic rections
Parasitic infections
Hodgkin Lymphoma

Question 18

What causes the eosinophilia seen with Hodgkin lymphoma?

Answer 18

Increased production of IL5

Question 19

What disease is basophilia classically seen with?

Answer 19

Chronic myeloid leukemia

Question 20

What are the 2 major causes of lymphocytic leukocytosis?

Answer 20

Viral infections

Bordetella pertussis infection

Question 21

What is the mechanism for lymphocytic leukocytosis seen with a viral infection?

Answer 21

T lymphocytes undergo hyperplasia when the cells are infected with the virus

Question 22

What causes lymphocytic leukocytosis when an individual is infected with Bordetella perussis?

Answer 22

The bacteria produces lymphocytosis-promoting factor. This blocks the circulating lymphocytes form leaving the blood and entering the lymph nodes.

Question 23

What are the stem cells that differentiate to form WBCs?

Answer 23

Hematopoietic CD34+ Stem cells

Question 24

What are the 2 arms of WBC development?

Answer 24

Myeloid stem cell

Lymphoid stem cell

Question 25

What can lymphoid stem cells differentiate in to?

Answer 25

Plasma cells | CD8+ and CD4+ T cells

Question 26

What can myeloid stem cells differentiate into?

Answer 26

``` RBCs Neutrophils Basophils Eosinophils Monocytes Megakaryocytes ```

Question 27

What are the two viral infections that can cause infectious mononucleosis?

Answer 27

EBV | CMV

Question 28

Infection by EBV causing lymphocytic leukocytosis comprised of reactive CD8+ T cells

Answer 28

Infectious mononucleosis

Question 29

How is EBV transmitted?

Answer 29

Transmitted by saliva—called the kissing disease

Question 30

Where are the primary sites of infection seen with EBV?

Answer 30

Oropharynx Liver B-cells

Question 31

An EBV infection of the oropharynx results in ________.

Answer 31

Pharyngitis

Question 32

What results when an EBV infection occurs in the liver?

Answer 32

Hepatitis with hepatomegaly and elevated liver enzymes

Question 33

With infectious mononucleosis CD8+ T-cells cause generalized lymphadenopathy. What is the cause of this abnormal process?

Answer 33

T-cell hyperplasia in the lymph node paracortex

Question 34

Where is the location of T-cell hyperplasia seen with infectious mononucleosis causing generalized lymphadenopathy?

Answer 34

Within the lymph node paracortex

Question 35

What causes splenomegaly seen with infectious mononucleosis?

Answer 35

T-cell hyperplasia within the periarterial lymphatic sheath (PALS)

Question 36

What test is used for screening of infectious mononucleosis?

Answer 36

Monospot test

Question 37

What does the monospot test, used to screen for infectious mononucleosis, detect?

Answer 37

IgM antibodies that cross-react with a heterophile antibody (horse or sheep RBCs)

Question 38

If a negative monospot test is obtain, what should one consider as the cause of infectious mononucleosis?

Answer 38

CMV

Question 39

How is a definitive diagnosis made with infectious mononucleosis caused by EBV?

Answer 39

Serologic testing for the EBV viral capsid antigen

Question 40

Why should patients who have been diagnosed with infectious mononucleosis within the last year avoid contact sports?

Answer 40

These patients are at an increased risk of splenic rupture

Question 41

What can patients with infectious mononucleosis develop if exposed to ampicillin?

Answer 41

A rash

Question 42

Dormancy of the EBV within B-cells can put patients at risk of developing what 2 complications?

Answer 42

Increased risk of recurrence of infectious mononucleosis Increased risk of B-cell lymphoma