Complete Blood Count with Diff Flashcards
CBC
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
WBC (Leukocytes)
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
Eosinophils (granulocyte)
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
Eosinophil morphology
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
Eosinophillia (excess eosinophils)
- 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)
Eosinopenia (Decreased count )
Usually related to increased circulating steroids
Other causes:
Cushings disease
Drugs (ACTH, epi, thyroxine, exogenous steroid use)
Acute bacterial infection
Basophils
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
Basophil Morphology
Mature basophil
Least common of WBCs (< 2%)
Nucleus does not always segment
Increase in response to same conditions that cause eosinophils to respond
Neutrophils (granulocyte)
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
Neutrophil Morphology
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
Pools of Neutrophils
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
Neutrophils
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
Neutrophils
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)
Neutrophilia
Pathologic
- Bacterial infection
- Certain viruses and fungi
- Inflammatory responses to tissue death (ex. Burns, snake bites
Drugs
- steroids
- lithium
causes of neutrophilia
Physiologic
- Pseudoneutrophilia (shift of cells from the MP to CP)
Ex. Catecholamines, acute stress
Other inflammatory responses
- Neoplastic growth
- Metabolic disorders
left shift
Left shift indicates rapid production of immature new neutrophils (“bands”).
***Usually caused by acute processes such as acute bacterial infection.
Right shift
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.
Causes of neutropenia
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
Lymphocytes (agranulocyte)
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
lymphocyte morphology
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
B lymphocytes
are most effective against bacteria & their toxins plus a few viruses
T Lymphocytes
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
B&T lymphocytes
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)
Causes of Lymphocytopenia
AIDS Bone Marrow Suppression Aplastic Anemia Steroids Transplant Anti-rejection drugs Antineoplastic drugs Multiple Sclerosis Myasthenia gravis Guillian-Barre Syndrome
causes of lymphocytosis
Influenza andviral pneumonia Varicella Herpes Simplex Herpes Zoster Mononucleosis Pertussis Tuberculosis Mumps Cytomegalovirus Infection Infectious Hepatitis
Monocytes
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)
Monocyte Morphology
Also not common in circulating blood
Stay in blood for about 70 hours
Become macrophages in tissue and live for several months or longer
