WBC Count And Differential Smear Flashcards
Where are WBC formed and what is the functions
- Formed in the bone marrow by stem cells
- Function is to fight infection and react against foreign bodies or tissues
*presence indicated inflammation / inflammatory process
What does WBC count measure
- Measures the total number of WBC in peripheral venous blood
What are the two components of a WBC count
- Total number of WBC
- Differential count (need to request)
What are the age related changes with WBC
- Newborns and infants have higher WBC than adults
- Elderly patients may not develop an elevated WBC count even with severe infection
- Low WBC count in the setting of fever/sepsis is a poor prognostic indicator
What are the critical values of WBC
<2000
>40000
What is leukocytosis and leukopenia
Osis = increased total WBC count >10,000
Penia = decreased total WBC count <4,000
What are some causes of leukocytosis
- Infection
- Leukemia
- Trauma, stress, exercise
- Dehydration
- Tissue necrosis (RA)
If the WBC count is high what should you do
Look at the differential
1. Neutrophils (bands/segs) = bacterial / pyogenic infection
2. Lymphocytes / monocytes = viral, TB
3. Eosinophils = allergy, parasites, coccidiomycosis (fungal)
What changes will occur in the WBC from infection (leukocytosis)
- There will be a left shift of Bands or segs (PMNs)
What is peripheral demargination due to (leukocytosis)
Steroids / pregnancy
1. Steroids will push WBC off the vessel wall and release them into the circulaon
2. If all the cells on the differential are proportionately elevated its from steroids
What types of cancers cause leukocytosis
Lymphoma / leukemia
1. Rapidly dividing cells, will have very high WBC with high lymphocytes (lymphoma)
2. High wbc with neutrophils, monocytes (leukemia)
What massive stressors cause leukocytosis
- MI
- PE
- Surgery
- Trauma
What are Myeloproliferative disorders
- Acquired condition in which something disrupts the production of blood cells
- The bone marrow makes deformed cells that die in the bone marrow or just after entering the blood stream
What types of cells will you see with myeloliferative disorders
- More immature and defective cells than healthy ones
*reason may see increased cell lines early in disease
*can progress to acute myeloid leukemia
What type of bone marrow failure conditions cause leukopenia
- Radiation
- Marrow infiltrate diseases (myelofibrosis)
- Dietary deficiencies (B12 or folate)
- Autoimmune disease
- Aplastic anemia
What is leukemia reactions
Found in sepsis
1. WBC count is extremely high and reaches levels associated with leukemia >50,000
*Leukostasis is WBC >100K seen in AML
*can resolve quickly as the infection is successfully treated
What does CBC with diff provide
- Provides all CBC components
*RBC, WBC, and platelets PLUS - Differential count
*measures the percentage of each type of leukocyte
*must be specifically requested
What are granulocytes (WBC)
- Cell with granules in cytoplasm
- Relapses enzymes during infection, allergic reaction, asthma
- Neutrophils, basophils, eosinophils
What are Agranulocytes
- Lymphocytes and monocytes
What are the five types of WBC on the differential
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
Never let monkeys eat bananas
If there is persistent increase, reduction, or dramatic decrease below normal range for the differential count what does that mean
Persistent increase = worsening infection
Reduction = resolution of an infection
Dramatic decrease below normal range = marrow failure
What makes up the majority of the total leukocytes
- Neutrophils and lymphocytes (75-90%)
What are neutrophils
- Most common granulocyte
- Multi-lobed (2 to 3)
*referred to as polymorphonuclear leukocytes PMN, segs or polys
*hypersegmented PMNs have 5 to 6 lobes
What is the first WBC to the scene of inflammation or infection
Neutrophils
*exist in the circulation for only 6 hours
What are immature neutrophils
When neutrophil production is stimulated significantly immature forms are released
1. Bands, stabs
*this is a shift to the left in WBC production
What does the term left shift mean
- Refers to an increase in the percentage of bands forms
*indicated an ongoing acture bacterial infection
How to determine a left shift
- > 10 to 12% bands are seen OR
- The total PMN (segs + bands) is >80
*segs are the mature form of a neutrophil
What is a right shift
- Indicated maturity of the cell (older neutrophils)
What can cause elevated neutrophils
- Physical or emotional stress
- Acute bacterial infection
- Acute fungal infection
- Cushing syndrome
- Inflammatory disorders
- Metabolic disorders
What causes decreased neutrophils
- Aplastic anemia
- Dietary deficiency
- Overwhelming bacterial infection (elderly)
- Viral infection
- Drug therapy (chemo)
- Addison disease
What is the primary function of lymphocytes
- To fight chronic bacterial infection and acute viral infection
*will arrive after neutrophils - Lymphocytes produce antibodies which are for immune memory
What is lymphocyte count a reflection of
T and B cell types
What are T cells
- Mature in the thymus
- Primarily involved with cellular type immune reactions
*circulate through the body where they recognize and kill pathogens
*Activate B cells to produce antibodies
*Store memory of past infections
What are B cells
- Mature in the bone marrow
- Humoral immunity (Antibody production)
When is the thymus the largest
- During infancy and childhood
*stops growing around adolescence and is reapplied by fat
*T cells migrate to the lymph nodes and throughout the body
What can cause elevated lymphocytes
- Chronic bacterial infection
- Viral infections (mumps, rubella)
- Lymphocytic leukemia
- Infectious mononucleosis
- Infectious hepatitis
What can cause decreased lymphocytes
- Leukemia
- Sepsis
- Immunodeficiency disease
- SLE
What are monocytes
Non granulocyte
1. Capable of fighting bacterial infection (more chronic)
2. Produced more rapidly than neutrophils and spend longer time in the circulation
What are some reasons for moncytosis
- Chronic inflammatory disorders
- Viral infections
- TB
- Chronic ulcerative colitis
- Parasites
What are some reasons for monocytopenia
- Aplastic anemia
- Drug therapy (prednisone)
- Hairy cell leukemia
* rare, slow growing cancer of the blood, bone marrow makes too many B cells, treated with Cladribine (chemo)
What are eosinophils
- Released in the blood
*allergic repsonse
*inflammatory response
*parasitic infections - Bigger role in allergies than basophils
- Does not respond to bacterial or viral infection
What are some causes of esinophilia
- Parasitic infections
- Allergic infections
- Eczema
- Leukemia
- Auto immune disease
What are some causes of esinopenia
- Increased adrenacorticsteroid production
What are basophils
- Least common of the circulation WBC
- Work with mast cells
- Contain histamine
- Involved in allergic reaction (less than eosinophils)
- Does not reposed to bacterial or viral infection
What are some causes of basophilia and basopenia
Philia = Myeloproliferative disease, leukemia (blast crisis in CML)
Penia = acute allergic reactions, hyperthyroidism, stress reactions
What is a blast crisis (basophilia)
- Phase of chronic myelogenous leukemia in which tiredness, fever, and an enlarged spleen occur during a increase in immature blasts cells form the marrow
What can affect the WBC count
- Final month of pregnancy and labor
- Splenectomy (mild to moderate elevation)
- WBC count lower in the morning and higher in late afternoon
- Drugs may increase or decrease
*prednisone
What does increased or decreased lobulation of neutrophils mean
Increased
1. >5 lobes defines hypersegmentation
2. Often bilobed nucleus and indicated inherited or acquired myeloid syndrome
What does granulation indicate on a WBC smear
Will be dark blue, coarse granules / vacuoles (toxic granulation)
1. Non specific findings of toxic systemic illnesses
What are Dohle inclusion bodies
- Most commonly seen in neutrophils
*severe infections, burns, malignancy, pregnancy - Represents areas of rough endoplamic reticulum with bound ribosomes
If there is a combination of Dohle bodies and toxic granulation what does that mean
You should be worried
What are smudge cells
Lymphocytes that appear flattened or smudged
1. Reflects abnl fragile B cells vulnerable to distortion of lymphocytes with mechanical manipulation
*characteristic of chronic lymphocytic leukemia (CLL)
What are Reed sternberg cells
- Malignant cells
- Cells appear very large with abundant pale cytoplasm and two or more oval lobulated nuclei
- Pathognomonic for Hodgkin lymphoma
What is a Philadelphia chromosome
- Specific genetic mutation of leukemia cancer cells
How is absolute count calculated
- Multiply the differential count of neutrophils by the total WBC count
*most common WBC count is absolute neutrophil count (ANC)
*lower the ANC, the more at risk for infection (neutropenia)
What ANC count are equivalent to severe risk of infection
Grade 4 = <500 severe risk
Grade 3 = 500 - 1,000 moderate risk
Grade 2 = 1,000 - 1,500 minimal risk
Grade 1 = 1,500 to 2,00 (safe to continue chemo)
What does absolute neutrophil count measure
- The number of neutrophil granulocytes present in the blood
- Physician look at ANC in cancer patients to determine ability to fight infection
What does a bone marrow biopsy test for
- For conditions impacting bone marrow
- Evaluates conditions involving cell lines
- Used to diagnose leukemia, bone marrow infiltrative disease, aplastic anemia and stage lymphomas
What is hyper cellular
Increased number of cells
What is hypocellular / hypopalstic
Decreed number of cells of containing less than the normal number of cells
