wbc labs - patient care

WBC role

defend body against invading organisms (bacteria, viruses, fungi)

WBC classifications

• granulocytes

  • neutrophils, basophils, eosinophils, monocytes

• lymphocytes

  • T cells, B cells, NK cells

normal WBC range

4-10 × 10³ cells/µL

leukopenia causes (low WBC)

• autoimmune conditions

• certain cancers/leukemia

• chemo

• radiation therapy

• malnutrition

• aplastic anemia

leukocytosis causes (high WBC)

• infection

• corticosteroids

• inflammation

• injury/surgery

• emotional stress

• bone marrow or immune disorders

• cancer

meds that cause leukopenia

• antibiotics (bactrim, cephalosporins)

• clozapine

• chemo

• antithyroid

meds causing leukocytosis

• corticosteroids

  • more WBC into circulation

• granulocyte colony stimulating factor

granulocyte characteristics

• largest subtype of WBCs

• phagocytes

• store chemicals needed to enzymatically destroy foreign cels

• differentiate and proliferate in bone marrow

lymphocyte characteristics

• 2nd major subtype of WBCs

• give specificity and memory to defense

differential

• breakdown of WBC types

• NOT found on CBC

• must be requested

• can be % or actual #

neutrophils

• most common WBCs

• bone marrow releases neutrophils in response to infection

• typically indicates bacterial infection

• 45-73% range = mature neutrophils (segmented neutrophils)

neutrophils - band & left shift

• less mature neutrophils are also released as body increases neutrophils in response to infection

• this causes left shift = increase in immature neutrophils = increased bands

• bands >/= 10% is a left shift

absolute neutrophil count (ANC)

• ANC = total WBCs x (% neutrophils + % bands)/ 100

• estimates body’s ability to fight infection

• measures both immature and mature neutrophils

neutropenia

• neutropenia can make you vulnerable to infection

• neutropenic fever

• ANC can be monitored for chemo initiation, antifungal/antibacterial prophylaxis for immunocompromised patients, etc

  • chemo prob cant be started till ANC > 1500

eosinophils

• regulate inflammation, present in intestinal mucosa/lungs

• destroy foreign substances

• typically respond to protozoa and worms

causes of eosinophilia

• parasitic infections

• worms

• allergic rxns

• chronic skin infections

• some cancers

causes of eosinopenia

• stress

• steroid exposure

basophils

• present in small #s in peripheral blood

• life span 2 weeks

• attributed to signs/symptoms of allergic response

basophilia causes

• hypersensitivity rxns

• allergic rxns

• some cancers

• chronic inflammation

basopenia causes

• stress

• hyperthyroidism

• prolonged steroid exposure

monocytes

• leave circulation & enter tissues when they mature into macrophages

  • present in lymph nodes, alveoli, spleen, liver, bone marrow

• present antigen to T cells

• ingestion & digestion of foreign material

• involved in destruction of old RBCs, denatured plasma proteins, lipids

lymphocytes characteristics

• give specificity and memory to body’s defense system

• 3 subgroups

• supgroups arent routine hematology test

3 lymphocyte subgroups

• T cells

  • cell mediated immunity, attack foreign cells

• B cells

  • antibody production

  • immunologic memory

• NK cells

  • tumor cell cytotoxicity, destroy virally infected cells

lymphocytosis causes

• viral infections

absolute values vs %

• values in differentiales are usually expressed as %

• absolute blood cell count = # blood cells as a given number

  • calculate = total WBC count x percentage of target count