Is thrombophilia screening necessary in Polycythemia Vera (PV)?

From the Guidelines

Thrombophilia screening is not recommended for patients with polycythemia vera (PV) as it does not significantly impact the management of the disease. PV itself is a myeloproliferative neoplasm that inherently carries an increased risk of thrombosis due to hyperviscosity, elevated red cell mass, and platelet abnormalities, as noted in the ESMO clinical practice guidelines for diagnosis, treatment, and follow-up of Philadelphia chromosome-negative chronic myeloproliferative neoplasms 1. The JAK2 V617F mutation, present in over 95% of PV cases, is already a significant thrombotic risk factor. Management of PV focuses on controlling hematocrit levels below 45% through phlebotomy, using low-dose aspirin (81-100 mg daily) for thromboprophylaxis, and cytoreductive therapy (such as hydroxyurea) in high-risk patients, as recommended by the European LeukemiaNet 1.

Key aspects of PV management include:

• Controlling hematocrit levels to reduce the risk of thrombotic events, as shown in the CYTO-PV trial 1
• Using low-dose aspirin for thromboprophylaxis, as demonstrated in the ECLAP study 1
• Cytoreductive therapy for high-risk patients, with options including hydroxyurea and IFN-α, as discussed in the European LeukemiaNet recommendations 1 Additional thrombophilia testing would rarely change this management approach and would not provide significant clinical value. The thrombotic risk in PV is primarily driven by the disease itself rather than by other inherited or acquired thrombophilic conditions. Resources are better directed toward optimal PV management, including regular monitoring of blood counts and addressing cardiovascular risk factors, rather than additional thrombophilia testing.

From the Research

Thrombophilia Screening in Polycythemia Vera (PV)

• The decision to perform a thrombophilia screen in patients with PV is not explicitly addressed in the provided studies 2, 3, 4, 5, 6.
• However, the studies suggest that patients with PV are at increased risk of thrombotic events, and that risk factors such as age, history of thrombosis, and elevated hematocrit levels can contribute to this risk 2, 3, 4, 5.
• The studies also discuss the importance of controlling hematocrit levels to reduce the risk of thrombosis, and the use of cytoreductive therapies and anticoagulation to prevent thrombotic events 2, 3, 4, 5, 6.
• In patients with PV who present with thrombosis, it is recommended to investigate for other congenital or acquired prothrombotic conditions, which may alter the long-term management of these patients 5.
• The provided studies do not specifically address the role of thrombophilia screening in PV, but rather focus on the management of thrombotic risk and the prevention of thrombotic events in these patients.

Risk Factors for Thrombosis in PV

• Age ≥ 60 years and history of thrombosis are identified as significant risk factors for thrombosis in PV patients 2, 4, 5.
• Elevated hematocrit levels, leukocytosis, and JAK2 mutation are also associated with an increased risk of thrombosis in PV patients 2, 3, 4.
• The studies suggest that controlling hematocrit levels and using cytoreductive therapies can help reduce the risk of thrombosis in PV patients 2, 3, 4, 5, 6.

Management of Thrombotic Risk in PV

• The primary goal of therapy in PV is to reduce the risk of thrombosis by controlling hematocrit levels to < 45% 2, 4, 6.
• Phlebotomy and low-dose aspirin are recommended for low-risk patients, while cytoreductive agents are recommended for high-risk patients 2, 4.
• The studies discuss the use of various cytoreductive therapies, including hydroxyurea, interferon, and ruxolitinib, in the management of PV patients 2, 4, 6.