Leukocytes, Granulocytes, and Monocytes

bone marrow

leukocytes, with the exception of T-lymphocytes, differentiate, proliferate, and mature here

thymous

T-lymphocytes are made in the bone marrow, but mature here

•released in the peripheral blood

•circulate briefly

•move into the tissues in response to stimulation

What happens to the leukocytes after they mature?

host defense, primarily in the tissues

function of mature leukocytes

between 2:1 and 4:1

normal myeloid to erythroid (M:E) ratio

leukemia

What could a high M:E ratio be a sign of?

•psychologic events (pregnancy, activity level, time of day)

•pathologic events (infections, immune responses, disorders)

•demographic (age, race, ethnicity, sex, etc.)

•clinical history (previous counts)

factors that will affect a patient’s WBC count

WBC count(falsely elevated) x 100 / 100 + #nucleated RBC count

formula for correcting falsely elevated WBC counts

neutrophils

the most numerous type of WBC in adult peripheral blood

segmented

the most common form that neutrophils take in peripheral fluid

40-80%

% of neutrophils in normal adult WBC count

50-60%

% neutrophils in a normal WBC count at birth

30%

% neutrophils in a normal WBC count at 4-6 months

bands

roughly 5% of neutrophils are composed of this form

0-5%

% eosinophils in a normal adult WBC count

0-1%

% basophils in a normal adult WBC count

yes

Is it considered normal to find no basophils in a WBC count?

malignancy

absolute basophilia (extremely high basophil count) can indicate the presence of this

2-10%

% monocytes in a normal adult WBC count

25-35%

% lymphocytes in a normal adult WBC count

30%

% lymphocytes in a normal WBC count at birth

65%

% lymphocytes in a normal WBC count at 4-6 months

cell surface markers

molecules on the surface of the cell

•cell lineage and subset within the lineage

•stage of maturation

•state of cell activation

cell surface markers can be used to identify:

protect host from infectious agents or pathogens

function of leukocytes

innate immune response

the body’s first response to common classes of invading pathogens

acquired (adaptive) immune response

an immune response that is slower to develop

1. myeloblast

2. promyelocyte

3. myelocyte

4. metamyelocyte

5. band

6. segmented neutrophil or polymorphonuclear neutrophil (PMN)

6 morphologically identifiable maturation stages of neutrophils

1. nucleoli disappear

2. chromatin condenses

3. round nuclear mass indents and segments

steps in the process of the development of the nucleus during neutrophil maturation

nucleoli

clearing spaces inside of a cell

2-3

amount of cell divisions in a myelocyte

mitosis

after the myelocyte, no stage of the neutrophil maturation is capable of this

granulocytopenia

decrease in all granulocytes in the blood

neutropenia

decrease in neutrophils in the blood

agranulocytosis

absense of granulocytes in the bloodhigh rish of de

high risk of developing infection

risk associated with agranulocytosis

granulocytosis

increase in all granulocytes in blood

neutrophilia

increase in neutrophils in the blood

reactive response to bacterial infection, metabolic intoxication, drug intoxication, or tissue necrosis

risk associated with neutrophilia

diurinal variation

the term used to describe the phenomenon of eosinophil counts being higher in the morning than in the evening

hypereosinophilic syndrome

persistent eosinophilia

eosinophilia

present in allergic diseases, parasitic infections, toxic reactions, GI diseases, respiratory tract diseases, or neoplastic disorders

tissue eosinophils

eosinophils present in tissues other than bone marrow, evidence that cells can mature in extramedullary sites

promyelocyte

stage of neutrophil maturation that contains purple granules

dawn of neutrophilia

clearing next to nucleus in a myelocyte

•dawn of neutrophilia

•secondary granules are orange-red

2 notable characteristics of the appearance of myelocytes in the process of maturation of neutrophils

50% or less

% indention in the nucleus during the metamyelocyte stage of neutrophil maturation

greater than 50%

% indention in the band stage of neutrophil maturation

3-5 lobes

during the segmented stage of neutrophil maturation, the nucleus is normally segmented into this many lobes

hyposegmented

a nucleus of a segmented neutrophil that has been segmented into less than 3 lobes

hypersegmented

a nucleus of a segmented neutrophil that has been segmented into more than 5 lobes

smaller

As a cell matures, it becomes ___.

fine, lacy

Chromatin is associated with a ___ pattern.

N:C (nucleus:cytoplasm)

Cells with little to no cytoplasm will have a higher ___ ratio.

blasts

cells that have little to no cytoplasm and a big nucleus

monocyte

eat and engulf macrophage in tissue

1. monoblast

2. promonocyte

3. monocyte

stages of maturation in a monocyte

blue-gray color, evenly dispersed with fine, dust-like membrane-bound granules

appearance of cytoplasm in a monocyte

histocytes

macrophages found in the tissues

erythrophagocytosis

a rare phenomenon seen in patients with diseases with clonal malignancies and the main cause of anemia in these patients

1. lyphocyte

2. lymphoblast

stages of lymphocyte maturation (for our purposes)

TdT+

CD marker for lymphoblasts

mononucleosis

an increase in reactive lymphocytes is an indication of this disease

multiple myeloma

sheets of lymphocytes in the blood indicate this disease