Platelets

Platelets, also known as thrombocytes, are small, colorless, irregularly-shaped blood cells that play a crucial role in the process of blood clotting (hemostasis). They are produced in the bone marrow and circulate in the blood.

Also Known As: Thrombocyte Count,  PLT,  Platelet Distribution Width,  PDW, Mean Platelet Volume,  MPV

Test Panel: Hemoglobin, Red Blood Cells (RBC), HCT, MCV, MCH, MCHC, Platelets Count, White Blood Cells (WBC), DLC, ESR

Why Get Tested:

• To diagnose the cause of petechial hemorrhage in the skin.
• To find the cause of spontaneous bleeding.
• In women with heavy menses.
• This is advised in a patient on chemotherapy.
• This is advised in case of bone marrow failure.
• Platelets count is of value in thrombocytopenia seen in:
  • Uremia.
  • Liver diseases.
  • malignancies.

When to Get Tested:

• As part of a routine complete blood count (CBC).
• When you have episodes of unexplained or prolonged bleeding.
• When you have symptoms that may be due to a platelet disorder.

Sample Required:

• This can be done on EDTA blood.
  • This is stable for 5 hours at 23 °C and 24 hours at 4 °C.
• Can take capillary blood and make a direct dilution, this sample is stable for 3 hours.
• Fetal blood is collected from the umbilical area percutaneous.
• The platelets can be assessed on the DLC slide.

Referance Ranges:

Test Name	Male	Female
Platelets Count	150 – 450 x 109 /l	150 – 450 x 109 /l

Critical value

• The patient may develop spontaneous bleeding when the count is < 20,000 /cmm.
• Platelets counts > 50,000 /cmm usually show no bleeding.

Causes of thrombocytopenia or Decreased platelets:

1. Idiopathic thrombocytopenia ITP.
2. Hypersplenism.
3. Anemias like pernicious, aplastic and hemolytic.
4. After a massive blood transfusion
5. Infection like viral, and bacterial,
6. Chemotherapy treatment.
7. HIV infection.
8. Leukemias, carcinoma, and myelofibrosis. This is due to the infiltration of the bone marrow.
9. D I C.
10. Toxemia of pregnancy, eclampsia.
11. Antiplatelets antibody.
12. Renal failure.
13. Inherited diseases like Wiskott-Aldrich syndrome.
14. An autoimmune disease like systemic lupus erythematosus

Thrombocytosis or increased platelets:

1. malignant tumors like leukemia, and lymphoma,
2. Polycythemia vera.
3. Splenectomy.
4. Iron deficiency anemia.
5. Autoimmune diseases like Rheumatoid arthritis, and SLE.
6. Hodgkin’s lymphoma
7. Chronic pancreatitis, and inflammatory bowel disease.
8. Tuberculosis.

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Possible References Used

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