Thrombopenie

Thrombopenie, or thrombocytopenia, is a condition characterized by a lower-than-normal platelet count in the blood. A normal count is roughly 150,000 to 450,000 platelets per microliter; thrombopenie is usually defined as fewer than 150,000/µL. Severity is often categorized as mild (100,000–150,000/µL), moderate (50,000–100,000/µL), or severe (<50,000/µL). Platelets are essential for primary hemostasis; reduced numbers increase the risk of spontaneous or provoked bleeding, especially from mucous membranes or after injury.

Causes are diverse and include decreased production in the bone marrow (e.g., marrow failure, leukemia, aplastic anemia, myelodysplastic syndromes, chemotherapy, alcohol use, certain nutrient deficiencies), increased destruction or consumption (immune thrombocytopenia—ITP; drug-induced immune thrombocytopenia; infections; disseminated intravascular coagulation; heparin-induced thrombocytopenia), sequestration in an enlarged spleen, and dilution after massive transfusion.

Clinical presentation ranges from asymptomatic to bleeding. Common signs are petechiae and purpura on the skin, nosebleeds, gum bleeding, and heavier menses. Very low counts can cause serious intracranial or GI bleeding.

Diagnosis starts with a complete blood count showing low platelets; a peripheral smear, coagulation tests, kidney and liver function, and pregnancy testing are used to identify causes. In some cases a bone marrow examination is needed.

Management depends on the cause and bleeding. Mild cases may be observed; immune thrombocytopenia is treated with steroids, IVIG, or anti-D; refractory cases may use rituximab, splenectomy, or thrombopoietin receptor agonists. Bleeding is treated with platelets or antifibrinolytics as needed, while NSAIDs are avoided. Prognosis varies by cause.