Week 2- White blood cell count and differential

Eosinophils

(1-4% of WBC's) *Allergic diseases* -engulf substances that trigger allergies. (eosin-red acidic dye)

Lymphocytes

(20-40% of WBC's) *Control process of immunity* Two kinds: T (thymus-direct attack) B (produce antibodies)

Neutrophils

(40-70% of WBC's) -Primary defence for bacterial infections -Locates, ingests and kills foreign invaders -Present in Band and Segmented forms

Monocytes

(<10% of differential) *Phagocytes in nature that become macrophages-> digest tissue debris and bacteria*

Bands make up what percentage of circulating neutrophils normally?

* <5% normally*

Leukopenia

*Abnormally low Leukocyte level* -commonly caused by certain drugs, bone marrow failure, or hypersplenism.

Lymphocytopenia

*Decrease in the number of lymphocytes* -corticosteroid therapy -HIV infection -Congestive HT failure

Thrombocytopenia

*Decreased thrombocytes* -hypersplenism -hemorrhage -immune thrombocytopenia -leukemia -cancer chemotherapy -Infection

The spleen

*Graveyard of blood cells* No spleen= Blood cells increase in circulation Hyperactive Spleen=Blood cells decrease in circulation

Leukocytosis

*High amount of WBC's* -generally indicates infection

Lymphocytosis

*Increase in number of lymphocytes* -Viral infections -Chronic infections: TB

Thrombocytosis

*Increased thrombocytes* -Malignant disorder like leukaemia/lymphomas -postsplenectomy syndrome -iron deficiency anemia -trauma -polycythemia vera (bone marrow disorder)

An increase in the number of bands is called?

*LEFT SHIFT* -Seen in acute infection -sign that bone marrow is secreting more *premature neutrophils*= Myeloid

*4) Platelet count (Thrombocyte count)*

-Platelets: small, round, anucleated cells -main function: maintain blood vessel integrity -Play important part in hemostasis platelet aggregation.

* 3)Left shift*

-response to acute infection -immature neutrophils are released into peripheral blood

*2) Differential WBC count*

1) Neutrophils (most abundant WBC, non-select. phagocy.) 2) Lymphocytes (very selective, make antibodies) 3) Monocytes (phagocytes ingest debris/bacteria 4) Eosinophils (phagocytes for allergens) 5) Basophils (heparin and histamine producers) *Heparin*- natural anticoagulant

White blood cell count and differential includes what?

1) Total white blood cell count 2) Interpreting Differential white count 3) Left Shift 4) Platelet count 5) Mean platelet volume

Hemostasis

1) Vasoconstriction 2) Platelet aggregation 3) Clot formation

If the neutrophils are causing leukocytosis....

Compare the neutrophil % to the total WBC -Percentage of neutrophils indicates the severity of infection.

Marked leukocytosis is usually due to?

Neutrophils or lymphocytes

* 1) Total WBC count*

Shows the status/quality of the immune system.

Monocytes are elevated in?

leukemia, hodgkin/non-hodgkin lymphoma, post splenectomy, protozoan infections, chronic inflammatory disordes, viral infections.