What causes thrombocytosis?

From the Guidelines

Thrombocytosis is primarily caused by myeloproliferative neoplasms (MPN), such as essential thrombocythemia (ET) or polycythemia vera (PV) 1.

Common Causes of Thrombocytosis

The most common causes of thrombocytosis include:

• Myeloproliferative neoplasms (MPN), including essential thrombocythemia (ET) and polycythemia vera (PV) 1
• Inflammatory conditions, such as rheumatoid arthritis or inflammatory bowel disease
• Infections, like tuberculosis
• Malignancies, including hematologic cancers
• Medications, such as corticosteroids, epinephrine, or heparin withdrawal
• Hemorrhage or blood loss
• Splenectomy or hyposplenism

In the context of MPN, leukocytosis and JAK2V617F mutation have been acknowledged as contributors to thrombotic tendency in both PV and ET 1. The International Prognostic Score of thrombosis for ET (IPSET-thrombosis) is used to determine thrombotic risk in ET, based on factors such as age, thrombosis history, JAK2V617F mutation, and cardiovascular risk factors 1.

It is essential to approach thrombocytosis with caution and consult a healthcare professional for proper evaluation and management, as an accurate diagnosis and treatment plan can only be determined after a thorough evaluation, including a complete medical history, physical examination, laboratory tests, and imaging studies as needed.

From the Research

Causes of Thrombocytosis

Thrombocytosis can be caused by various factors, including:

• Primary thrombocytosis, which is a myeloproliferative neoplasm associated with mutations of genes that regulate thrombopoiesis (eg, JAK2) 2, 3, 4
• Reactive (secondary) thrombocytosis, which is frequently encountered in the family medicine setting and can be caused by:
  • Tissue injury 3
  • Infection 3
  • Chronic inflammatory disorders 3
  • Iron deficiency anemia 3
• Familial mutations 4
• Essential thrombocythemia (ET) and other myeloproliferative disorders (MPDs) 4
• Drug-induced thrombocytosis, including:
  • Adrenalin 5
  • Vinca alkaloids 5
  • Miconazole 5
  • Iron 5
  • Beta-lactam antibiotics (although the data is difficult to interpret) 5

Types of Thrombocytosis

There are two principal types of thrombocytosis:

• Essential (primary) thrombocythemia, which is a myeloproliferative neoplasm associated with mutations of genes that regulate thrombopoiesis (eg, JAK2) 2, 3, 4
• Reactive (secondary) thrombocytosis, which is frequently encountered in the family medicine setting and can be caused by various factors, including tissue injury, infection, chronic inflammatory disorders, and iron deficiency anemia 3