From the Guidelines
Thrombocytopenia is primarily caused by decreased production of platelets, increased destruction of platelets, or sequestration of platelets, with immune thrombocytopenia (ITP) being a leading cause of increased destruction, as evidenced by the American Society of Hematology 2011 guideline 1. The causes of thrombocytopenia can be broadly categorized into three mechanisms:
- Decreased production of platelets in the bone marrow, which can result from bone marrow disorders such as leukemia, aplastic anemia, myelodysplastic syndromes, or vitamin B12 and folate deficiencies, as well as certain medications that suppress platelet production, including chemotherapy drugs, alcohol, and some antibiotics.
- Increased destruction of platelets in the peripheral circulation, which occurs in immune thrombocytopenia (ITP), where the immune system attacks platelets, and in conditions like disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), and hemolytic uremic syndrome (HUS), with ITP being characterized by immunologic destruction of otherwise normal platelets, often in response to an unknown stimulus 1.
- Sequestration of platelets in the spleen, which occurs in conditions causing splenomegaly, such as liver cirrhosis or portal hypertension, where the enlarged spleen traps platelets. Infections, particularly viral infections like HIV, hepatitis C, and COVID-19, can cause thrombocytopenia through various mechanisms, including increased destruction and decreased production, as noted in the international consensus report on the investigation and management of primary immune thrombocytopenia 1. Identifying the underlying cause of thrombocytopenia is crucial for appropriate management, as it can significantly impact morbidity, mortality, and quality of life, with the American Society of Hematology 2011 guideline providing evidence-based recommendations for the diagnosis and management of ITP 1.
From the FDA Drug Label
8 Hematologic Disorders Idiopathic thrombocytopenic purpura in adults Secondary thrombocytopenia in adults Acquired (autoimmune) hemolytic anemia Erythroblastopenia (RBC anemia) Congenital (erythroid) hypoplastic anemia
The causes of thrombocytopenia (low platelet count) mentioned in the label are:
- Idiopathic thrombocytopenic purpura
- Secondary thrombocytopenia 2