Lab - WBC

How did we measure the total WBC count? What tool did we use? What was the basic procedure?

Began by filling a small capillary tube with blood, and then isolated WBC from RBC with lysis solution in conical tube. The total WBC count was measured with a hemocytometer “blood cell measure.” Four large squares were counted, with the expectation of seeing 25-50 WBC/square. To calculate the concentration all the squares were added (A+B+C+D) and times 50 as the dilution factor to get the total WBC count. We expect about 25-50 WBC/square for a total number of cells between 5000 and 10000 WBC per microliter of blood.

What does multiplying by the dilution factor of 50 do?

adjusts for dilation and volume counted

What may the results obtained be influenced by?

dilution accuracy and sample homogeneity

What was the procedure for differential WBC count?

By making a smear blood slide (x2) and staining it with different solutions. The slide is then placed under the microscope as 100 cells are counted, starting from the feathered end and zig zagging to prevent counting the same cell again.

Which WBCs are granulocytes? agranulocytes?

G: Neutrophils, Eosinophils, and Basophils

A: Lymphocytes and Monocytes

Neutrophils: percentage, appearance, and functions

60-70%

multilobed nucleus and neutral stained granules

First responders phagocytes capable of diapedesis. The numbers of neutrophils increases during bacterial/acute infections. They have a very short lifespan, lasting from seconds to minutes, reason why 75% of production is WBC as they make 60-70% of them.

Lymphocytes: percentage, appearance, and functions

20-25%

smallest in size with a large nucleus with a thin rim of cytoplasm

Myeloid and lymphoid origin, lymphocytes are capable of diapedesis and have three different subtypes: natural killer cells (nonspecific), B cells, and T cells (specific). The main functions of lymphocytes is immunomemory, organ rejection, and allergic reactions.

Lymphocytes: NK cells, T cells, and B cells

NK cells: rapid-response lymphocytes of the innate immune system that detect and destroy virus-infected cells and early-stage cancer cells

T cells: myeloid origin, mature in thymus, and migrate out to lymph tissue.

• Helper T cells: activate cytotoxic T cells and B cells

• Cytotoxic T cells: fight virus infected or cancer cells, binding and secreting chemicals to kill them

B cells: myeloid origin, mature in RBM, migrate out to lymph nodes

• produce antibodies, fighting specific infections by binding onto antigen

Lymphocyte Functions: immunomemory, organ rejection, and allergic reactions.

immunomemory: when antigen is met B and T cells produce memory B and T cells that remained stored in your body, so when the antigen is met again a quick response is amounted and possibly may not even get sick

organ rejection: a downside of immunomemory in which it amounts an immune response against an organ transplant (why immunosuppressants are taken)

Causes allergies: stimulates inflammation response against an antigen that normally should not cause a response

Monocytes: percentage, appearance, and functions

3-8%

largest in size with a u or bean shaped nucleus

Myeloid and lymphoid origin, monocytes are the strongest and longest lasting WBC. They are stronger, more effective, but slower phagocytes than neutrophils that fight infections. When a person is fighting a chronic infection numbers increase.

When monocytes migrate out from blood to tissues (diapedesis) they become macrophages.

Eosinophils: percentage, appearance, and functions

2-4%

bilobed nucleus with reddish- pinkish (eosin) granules

Fight parasitic worm infections by binding onto them and secreting chemicals. They also protect against hypersensitivity by making antihistamine (fighting allergies). Numbers increase when fighting a parasitic worm infection

Basophils: percentage, appearance, and functions

0-1%

s shaped nucleus typically hidden by dark purple stained granules

Only WBC not capable of diapedesis because mast cells in the tissue do the same thing. Basophils function to enhance allergic (inflammatory) response by releasing histamine to dilate blood vessels, serotonin to increase capillary permeability, and heparin as an anticoagulant, preventing the clotting of blood.

What is the normal WBC count? What is it called if its under? over?

Normal WBC count is 5000 to 10000 WBC/μl. If its under 5000μl its called leukopenia, if its over 10000μl it is called leukocytosis.

What is leukopenia?

When the Total WBC count is lesser than 5000μl, it is leukopenia, a pathological condition that is NEVER normal because it means the person is immunocompromised. As the individual does not have enough WBCs to fight an infections we begin to see some not normally seen in people that are not immunocompromised.

What may be some causes for leukopenia?

It could be hormones: the body is not producing enough leukopoietin to stimulate pluripotent hematopoietic stem cell or colony stimulating factors to specify generic WBC

Bone marrow disease

HIV: virus that infects lymphocytes and destroys them

Chemotherapy: because it destroys any cells that divides rapidly, therefore affecting WBCs that produce at a greater rate (75%)

What is leukocytosis? Is it good or bad?

When the total WBC count is greater than 10000μl. Leukocytosis can be both good and bad. Its good when a person is fighting an infection. It is bad when its leukemia, bone cancer where there is uncontrolled proliferation of WBCs but they are not effective. Leukemia has two origins, myeloid and lymphoid

Meghan thinks she has an abscessed tooth (a bacterial infection). If she does, what type of white blood cell would you expect to see in elevated numbers in a differential count?

 

neutrophils

A patient has elevated eosinophils and monocytes but normal levels of neutrophils, basophils, and lymphocytes. Which of the following could be causing those levels?

 

a chronic parasitic infection

A patient has elevated neutrophils and monocytes with normal levels of basophils, eosinophils, and lymphocytes. Which of the following is the most likely cause of these test results?

a chronic bacterial infection