Platelet dysfunction may be due to a problem in the platelets themselves or to an external factor that alters the function of normal platelets.
(See also Overview of Platelet Disorders and Overview of Thrombocytopenia.)
Platelets are cells that are made in the bone marrow and circulate in the bloodstream and help blood clot. The blood usually contains about 140,000 to 440,000 platelets per microliter (140 to 440 × 109 per liter). When the platelet count falls below about 50,000 platelets per microliter of blood (50 × 109 per liter), bleeding can occur even after relatively minor injury. The most serious risk of bleeding, however, generally does not occur until the platelet count falls below 10,000 to 20,000 platelets per microliter of blood (10 to 20 ×109 per liter). At these very low levels, bleeding may occur without any recognized injury.
When platelets do not function properly, people are at risk of excessive bleeding due to injuries or even spontaneous bleeding. Platelet dysfunction may be
Inherited
Acquired
Matatizo ya chembe sahani ya kurithi
Von Willebrand disease is the most common inherited platelet-related disorder. There are a number of other rare inherited disorders that affect platelets, including Glanzmann disease, Wiskott-Aldrich syndrome, Chédiak-Higashi syndrome, and Bernard-Soulier syndrome. Some of these syndromes include skin disorders, abnormalities in immune function, and reduced kidney function.
Matatizo ya chembe sahani yaliyopatikana
Acquired platelet disorders are usually caused by certain
Medications
Diseases
The most common medications that affect platelet function are aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), along with antiplatelet medications such as clopidogrel and similar medications that are used to prevent strokes and heart attacks.
Diseases that can affect platelet function include cirrhosis, multiple myeloma, kidney disease, and systemic lupus erythematosus (lupus).
Some people can develop platelet dysfunction after cardiopulmonary bypass during open-heart surgery.
Dalili za Chembe Sahani Kutofanya Kazi
Symptoms depend on the cause and severity of platelet dysfunction.
People with inherited disorders of platelet dysfunction may have a lifelong history of easy bruising or excessive bleeding after minor injuries or minor surgery such as dental extractions. Boys may have had excessive bleeding after circumcision. Sometimes the first sign in women is that their menstrual periods are very heavy.
Other symptoms of platelet disorders include tiny dots (usually red or purple) called petechiae on the skin and bruising after minor injuries.
Ekimosisi ni michubuko mikubwa ya zambarau inayoonekana hapa kwenye mguu.
DKT P. MARAZZI/MAKTABA YA PICHA ZA KISAYANSI
Petechiae are small red, purple, or brown spots as seen here in the skin.
By permission of the publisher. From Deitcher S. In Atlas of Clinical Hematology. Edited by JO Armitage. Philadelphia, Current Medicine, 2004.
Petechiae ni madoa madogo mekundu kama yanavyoonekana hapa mdomoni.
DKT P. MARAZZI/MAKTABA YA PICHA ZA KISAYANSI
Ekimosisi ni michubuko mikubwa ya zambarau inayoonekana hapa kwenye mguu.
DKT P. MARAZZI/MAKTABA YA PICHA ZA KISAYANSI
Petechiae are small red, purple, or brown spots as seen here in the skin.
By permission of the publisher. From Deitcher S. In Atlas of Clinical Hematology. Edited by JO Armitage. Philadelphia, Current Medicine, 2004.
Petechiae ni madoa madogo mekundu kama yanavyoonekana hapa mdomoni.
DKT P. MARAZZI/MAKTABA YA PICHA ZA KISAYANSI
Utambuzi wa Ugonjwa wa Chembe Sahani Kutofanya Kazi
Blood tests to measure platelet count and clotting
Special tests to measure platelet function and bleeding
Doctors suspect a medication is causing platelet dysfunction if symptoms begin after a person starts taking that medication. Doctors suspect an inherited cause if symptoms begin early in life in people who do not have any other disorders or do not take any medications that cause platelet dysfunction.
Doctors first do a complete blood count (CBC) to measure the number of platelets and see whether the person's symptoms are caused by a low number of platelets (thrombocytopenia). If the number of platelets is normal, doctors suspect there may be platelet dysfunction. If the cause is not clear, doctors may need to do other blood tests to measure substances that are involved in clotting (prothrombin time [PT] and partial thromboplastin time [PTT]). These tests measure how long it takes blood to clot. In other tests, called platelet function tests, a sample of blood is collected and tested to see if platelets react normally to various platelet stimulators. Abnormal platelet function tests may indicate the nature of the inherited or acquired platelet dysfunction.
Matibabu ya Chembe Sahani Kutofanya Kazi
Stopping or avoiding medications that cause bleeding
Treating the underlying associated disease, for example, dialysis for a person with kidney failure
Sometimes medications that decrease bleeding or sometimes platelet transfusion
If platelet dysfunction is caused by a medication, stopping the medication usually is the only treatment needed. People with an inherited platelet disorder that causes excessive bleeding usually should not take medications that impair platelet function.
When people with an inherited platelet dysfunction have serious bleeding, they may need a platelet transfusion or a medication called desmopressin, which helps decrease bleeding.
Bleeding that occurs with minor procedures or with menstruation may be prevented by another medication, tranexamic acid, which improves how well the blood clots.
