An increase in the number of platelets in the blood is called thrombocytosis, and a decrease is called thrombocytopenia. Platelets close the bleeding point by providing coagulation when there is vascular damage anywhere in the body to prevent blood loss. While performing this function, the ability of the platelet to orient to the bleeding area, to be activated, to secrete the needed proteins and to adhere to the damaged area is used.

Platelets

Platelets are small cells that are produced by differentiation from the initial cells called megakaryocytes in the bone marrow and are involved in blood coagulation processes. There is an average of 150,000-400,000/mm3 platelets in the blood. Platelets are produced by triggering a protein called thrombopoietin. The average lifespan of platelets is 8-10 days. End-of-life platelets are broken down in the spleen. About 70% of platelets are found in the bloodstream and 30% are found in the spleen.



An increase in the number of platelets in the blood is called thrombocytosis, and a decrease is called thrombocytopenia. Platelets close the bleeding point by providing coagulation when there is vascular damage anywhere in the body to prevent blood loss. While performing this function, the ability of the platelet to orient to the bleeding area, to be activated, to secrete the needed proteins and to adhere to the damaged area is used. Many substances necessary for platelets to perform this function are secreted. These substances are stimulants secreted from different cells and tissues such as thromboxane A2, thrombin, adrenaline. When the platelets receive the stimulus, they quickly become involved in the process by secreting the necessary substances within themselves and ensure coagulation. Some of the substances in the platelets that are secreted and effective in the coagulation process are serotonin, ADP, Ca+2, Factor1, Factor 5, Factor 8, platelet factor-3 (PF-3), platelet factor-4 (PF-4), b-thromboglobulin ( b-TG), heparin neutralizing protein, Thrombospondin, Von Willebrand Factor (vWF), platelet-derived growth factor (PDGF).

Changes in the number of platelets

A decrease in the platelet count below 150,000/mm3 does not immediately cause bleeding disorders. The probability of bleeding varies according to the other conditions of the patient. Chance of bleeding:

  • If there is more than 50,000/mm3 platelet count and there is no abnormality in platelet structures, it is sufficient to prevent bleeding.
  • If the platelet count is greater than 20,000/mm3, if there is no abnormality in platelet functions, minor bleeding can be prevented, but major bleeding is risky.
  • A thrombocyte count of 10,000/mm3 or less is a condition that cannot prevent even spontaneous bleeding. Spontaneous nosebleeds, skin petechiae, and gingival bleeding may occur.

The possibility of intracranial bleeding in infants and children with low platelet levels is very important and risky. All patients with a low platelet count must undergo a detailed cause analysis and seek medical attention. Along with platelet counts, their shape, characteristics, and status of other blood cells should be evaluated.



Not every patient with bleeding may have low platelet count. The deficiency of other non-platelet substances in coagulation factors can also cause bleeding. In fact, some situations in which platelets proliferate excessively can cause bleeding due to mechanical failures of coagulation.

Thrombocytopenia

Sometimes, although thrombocytopenia is seen in hemogram tests, thrombocytopenia may not be seen in the count made with a microscope by peripheral smear. This is caused by the chemical substance contained in the test tubes from which blood is drawn and the platelets in the sample reacting and breaking down. This is called false thrombocytopenia.

There are hundreds of diseases and conditions that cause thrombocytopenia. Some of these are rare hereditary diseases. Causes of thrombocytopenia are usually non-hereditary conditions.

The development of thrombocytopenia may be caused by platelet production and functions and all the stages it has undergone throughout its life. These processes are briefly:

  • Decreased platelet production
  • Increased platelet consumption-breakdown
  • Abnormal collection of platelets in the spleen
  • Hemodilution

Inherited diseases that cause thrombocytopenia:

  • Autosomal dominant thrombocytopenia diseases
    • May-Hegglin anomaly
    • Fechtner syndrome
    • Epstein syndrome
    • Sebastian syndrome
    • Familial platelet disease/AML
    • Chromosome 10/THC2
    • Gray platelet syndrome
    • Jacobsen syndrome
  • Autosomal recessive thrombocytopenia diseases
    • Congenital amegakaryocytic thrombocytopenia (CAMT)
    • Thrombocytopenia and absence of radius (TAR)
    • Bernard-Soulier syndrome
    • Glanzmann’s disease
  • X-linked thrombocytopenia diseases
    • Wiskott-Aldrich Syndrome (WAS)
    • X-linked thrombocytopenia
    • GATA-1 mutation

Drug-induced thrombocytopenia

Some drugs can cause thrombocytopenia by having abnormal effects at any stage of platelet production and activity processes. For example, a single adult dose of acetylsalicylic acid can prolong bleeding time by up to one week. Some of these drugs are:

  • Acetyl salicylic acid
  • Heparin
  • Quinine
  • Sulfanamides
  • Acetaminophen
  • Cimetidine
  • Ibuprofen
  • Naproxen
  • Ampicillin
  • Piperacillin
  • Vancomycin
  • Glycoprotein IIb/IIIa inhibitors
  • Antibiotics
  • Antidepressants

Nutritional thrombocytopenia

Nutritional habits are also conditions that can cause thrombocytopenia. These foods should not be consumed in high doses, especially by risky people. Some foods that cause thrombocytopenia:

  • Drinks containing quinine
  • Walnut
  • Some herbal teas
  • Spices (Mint, thyme, cumin, black pepper, paprika)
  • Dill
  • Rosemary
  • Turmeric
  • Tomatoes
  • Mushroom
  • Apricot
  • Blackberry
  • Raspberry
  • Raisins

Other causes of thrombocytopenia:

The reasons listed below are other common causes of thrombocytopenia, and there are many other causes of thrombocytopenia.

  • Decreased or defective platelet production
    • Congenital causes
    • Acquired causes
      • Aplastic anemia
      • Bone marrow infiltration
      • Radiation toxicity
      • Chemotherapy
      • Direct toxicity to platelet production
      • Cyclic thrombocytopenia (menstruation period)
    • Nutritional reasons
      • Vitamin B12 deficiency
      • Folic acid deficiency
      • Iron deficiency
    • Viral infections
    • Paroxysmal nocturnal hemoglobinuria
    • Spleen diseases
      • Congestive conditions
      • Neoplasms
      • Infiltrations
      • Infections
    • Other situations
      • Heat stroke
      • Burns
      • Endocrine causes
    • Increased platelet destruction
      • Giant cavernous hemangioma (Kasabach-Meritt syndrome)
      • Infections
      • Disseminated intravascular coagulation (DIC)
      • Thrombotic thrombocytopenic Purpura
      • Hemolytic uremic syndrome
      • Drug-related conditions
      • Posttransfusion
      • Idiopathic thrombocytopenic purpura
      • Connective tissue diseases
      • Extracorporeal circulation
    • Thrombocythemia
      • Myeloproliferative diseases
      • Chronic inflammatory conditions
      • Acute inflammation
      • Acute bleeding
      • Iron deficiency
      • Hemolytic anemias
      • Malignant diseases
      • Posterative situations
      • Drug-related causes
      • Postexercise conditions
    • Thrombocytopenic purpura
      • Acute idiopathic thrombocytopenic purpura
      • Chronic idiopathic thrombocytopenic purpura
      • Platelet sequestration (Hypersplenism)
    • Other reasons
      • Vitamin K deficiency
      • Liver diseases
      • Kidney diseases
      • Autoimmune diseases
      • Frequent blood transfusions
      • After bone marrow transplant
      • Incorrect use of anticoagulants
      • Alcohol
      • Pregnancy

 


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