Complete Blood Count with Diff

Question 1

CBC

Answer 1

Helps assess immune function, O2 and CO2 carrying capacity, hemostasis
Costs about $20.00
Used to be hand counted now done by electrical impedance or optical recognition

Question 2

WBC (Leukocytes)

Answer 2

Neonates and infants (9-30 cells/L)
Normal adult range (4.5-11 cells/L)
Two categories of leukocytes:
Granulocytes
-Eosinophils
-Basophils
-Neutrophils

Agranulocytes

• Lymphocytes
• Monocytes

Question 3

Eosinophils (granulocyte)

Answer 3

Eosinophils have cytotoxic and anti-inflammatory functions
- Heavily involved in allergic reactions
Normal reference range: 1-4% of total WBC
Also function as phagocytes but appear to be less potent than neutrophils
Drawn to sites of hypersensitivity reactions by mast cell chemotactic factors
Play a role in parasitic infections

Question 4

Eosinophil morphology

Answer 4

Segmented eosinophil

Life span = 14 days

Spends little time in the blood before it locates in the skin, GI tract, or respiratory tract

Only 1% of mature cells are located in blood

Question 5

Eosinophillia (excess eosinophils)

Answer 5

• mild (700-1500 per microliter) seen in allergic rhinitis, extrinsic asthma, mild drug reactions, long-term dialysis, immunodeficiency
• moderate (1500-5000 per microliter) parasitic diseases, intrinsic asthma, pulmonary eosinophilia syndrome
• marked (>5000 per microliter) trichina, hookworm, toxicara canis, eosinophilic leukemia, severe drug reaction

Can be drug induced eosinophilia
(antibiotics, gold compounds, ASA, anti-cancer meds, Dilantin)
Can be due to certain diseases
(RA, psoriasis, IBD, lupus, malignancies, hypopituitarism)

Question 6

Eosinopenia (Decreased count )

Answer 6

Usually related to increased circulating steroids

Other causes:
Cushings disease
Drugs (ACTH, epi, thyroxine, exogenous steroid use)
Acute bacterial infection

Question 7

Basophils

Answer 7

Mediate allergic reactions along with eosinophils
Normal reference range (0.5-2% of total WBC)
Causes of basophilia
hypothyroidism, myxedema, ulcerative colitis, polycythemia vera, urticaria, Hodgkin’s lymphoma, chicken pox, splenectomy
Basopenia is not an issue

Question 8

Basophil Morphology

Answer 8

Mature basophil

Least common of WBCs (< 2%)

Nucleus does not always segment

Increase in response to same conditions that cause eosinophils to respond

Question 9

Neutrophils (granulocyte)

Answer 9

Neutrophils are normally the most prominent WBC and are phagocytic.
Normal reference range (55-70% of total WBC)
Polymorphonuclear (PMN) indicates the age of neutrophil, the more segments, the more mature the neutrophil cell is
Neutrophilia- relative >70% (absolute count > 8000).
- Most common reason for leukocytosis are acute bacterial infections and trauma

Question 10

Neutrophil Morphology

Answer 10

Segmented neutrophil (40-70% of WBCs)

Life span of about 10 days

Moves from bone marrow to blood to tissues

Mature more quickly under stressful conditions

Primary defense for bacterial infections

Question 11

Pools of Neutrophils

Answer 11

Bone marrow: many banded forms are present; neutrophilia with lots of bands suggest bone marrow was source

Circulating Pool: used to deal with day to day invasion of the body by organisms

Marginated Pool: no bands; respond to physiologic stimulation

Question 12

Neutrophils

Answer 12

Once in the peripheral blood, they can be in the circulating pool (CP) or the marginated pool (MP)
Cells in MP not counted in CBC
Shift from the MP to the CP can occur with stress, trauma, catecholamines, etc.
- This results in a transient leukocytosis
- Such leukocytosis can last 4-6 hours

Question 13

Neutrophils

Answer 13

Present in band (“babies) and segmented (“senior”) forms
Bands make up < 5 % of circulating neutrophils normally
“Left shift” is seen as an increase in the number of bands and is common with acute infection
- When neutrophil production is significantly stimulated, early immature forms (the bands) will enter the circulation in higher numbers than the mature segmented forms.
Main function of neutrophilsis to locate, ingest, and kill bacteria and other foreign invaders (phagocytosis)

Question 14

Neutrophilia

Answer 14

Pathologic

• Bacterial infection
• Certain viruses and fungi
• Inflammatory responses to tissue death (ex. Burns, snake bites

Drugs

• steroids
• lithium

Question 15

causes of neutrophilia

Answer 15

Physiologic
- Pseudoneutrophilia (shift of cells from the MP to CP)
Ex. Catecholamines, acute stress

Other inflammatory responses

• Neoplastic growth
• Metabolic disorders

Question 16

left shift

Answer 16

Left shift indicates rapid production of immature new neutrophils (“bands”).
***Usually caused by acute processes such as acute bacterial infection.

Question 17

Right shift

Answer 17

Right shift is characterized by increased PMNs (few bands with neutrophilia).

• Seen in liver disease, megaloblastic anemia, hemolysis, some medications, cancer, allergies.
• Prognosis is related to cause and history helps narrow cause.

Question 18

Causes of neutropenia

Answer 18

Decreased Production of WBCs

• bone marrow diseases
• malignancies that affect the bone marrow

Increased Neutrophil Destruction

• overwhelming infection
• certain bacteria
• immune reactions

Pseudoneutropenia (shift of cells from CP to MP)

• viral infections
• hypothermia

Question 19

Lymphocytes (agranulocyte)

Answer 19

After neutrophils, lymphocytes are most numerous of circulating leukocytes.
Normal reference range is 1000-4800/ mcg L.
Comprised of:
- T-cells (also known as CD-4 cells)
- B-cells

Question 20

lymphocyte morphology

Answer 20

May mature into B or T-cells

Main function is antigen recognition and immune response

Life span quite varied (up to two years)

Can pass back and forth between blood and tissues

Question 21

B lymphocytes

Answer 21

are most effective against bacteria & their toxins plus a few viruses

Question 22

T Lymphocytes

Answer 22

recognize & destroy body cells gone awry, including virus-infected cells & cancer cells.
T-cells come in two types:
- “helper cells” and “suppressor cells”
- normally the helper cells predominate

Question 23

B&T lymphocytes

Answer 23

B-cells are not only produced in the bone marrow but also mature there.

However, the precursors of T-cells leave the bone marrow and mature in the thymus (which accounts for their designation)

Question 24

Causes of Lymphocytopenia

Answer 24

AIDS
Bone Marrow Suppression
Aplastic Anemia
Steroids
Transplant Anti-rejection drugs
Antineoplastic drugs
Multiple Sclerosis
Myasthenia gravis
Guillian-Barre Syndrome

Question 25

causes of lymphocytosis

Answer 25

Influenza andviral pneumonia
Varicella
Herpes Simplex
Herpes Zoster
Mononucleosis
Pertussis
Tuberculosis
Mumps
Cytomegalovirus Infection
Infectious Hepatitis

Question 26

Monocytes

Answer 26

Monocytes mature into macrophages which participate in the removal of foreign substances and cellular debris from the body.
They are also responsible for the destruction of old erythrocytes, denatured plasma proteins, and plasma lipids and the salvage of iron.
Normal reference range (200-950/ mcg L) (or 2-8% of total WBC).
Become “activated” when direct contact with microorganisms occurs
Activated cells have greater motility, enzyme activity and killing capacity (causes fever)

Question 27

Monocyte Morphology

Answer 27

Also not common in circulating blood

Stay in blood for about 70 hours

Become macrophages in tissue and live for several months or longer