What is the relationship between Sickle Cell Trait (SCT) and hypercoagulability?

From the Guidelines

Relationship between Sickle Cell Trait (SCT) and Hypercoagulability

Individuals with Sickle Cell Trait (SCT) may have an increased risk of hypercoagulability, which can lead to a higher risk of thrombotic events.

• The evidence suggests that SCT is associated with an increased risk of venous thromboembolism (VTE) 1.
• As a precautionary measure, it is recommended that individuals with SCT take low-dose aspirin (81 mg daily) to reduce the risk of thrombosis, especially during periods of high risk such as surgery, trauma, or immobilization 1.
• Additionally, hydration and mobilization should be encouraged to reduce the risk of thrombosis.
• In certain situations, such as high-risk surgery or pregnancy, consideration may be given to the use of low molecular weight heparin (e.g. enoxaparin 40 mg subcutaneously daily) for thromboprophylaxis 1.
• However, the decision to use anticoagulant therapy should be made on a case-by-case basis, taking into account the individual's overall risk profile and medical history.
• It is also important to consider the potential risks and benefits of anticoagulation, including the risk of bleeding, and to regularly reevaluate the need for anticoagulation 1.
• The selection of anticoagulant should also take into account comorbidities such as renal impairment that may affect drug clearance 1.

From the Research

Relationship between Sickle Cell Trait (SCT) and Hypercoagulability

• Sickle cell disorders, including Sickle Cell Trait (SCT), are associated with a hypercoagulable state that may contribute to vaso-occlusive episodes 2.
• Studies have shown that individuals with SCT have increased coagulation activity, with elevated levels of d-dimers, thrombin-antithrombin (TAT) complexes, and prothrombin fragment 1.2 (F1.2) 2.
• The degree of coagulation activation parallels the degree of disease severity among sickle cell genotypes, with SCT having lower coagulation activity compared to Hb SC and Hb SS disease 2.
• The hypercoagulable state in SCT is thought to be driven by disease severity, with monocytosis and the possible expression of monocyte-derived tissue factor contributing to the increased coagulation activity 2.
• Other studies have also found that SCT is associated with a procoagulant state, with increased levels of factor VIII, von Willebrand factor, and D-dimer, and decreased levels of ADAMTS 13 activity 3.
• The hypercoagulable state in SCT may increase the risk of thromboembolism, with case reports documenting unprovoked venous thromboembolism in patients with SCT 4.
• Additionally, SCT may impact outcomes in multisystem trauma, with increased risk of venous thromboembolism and chronic kidney disease, although more research is needed to fully understand this relationship 5.

Key Findings

• SCT is associated with a hypercoagulable state, with increased coagulation activity and elevated levels of coagulation markers 2, 3.
• The degree of coagulation activation in SCT is lower than in Hb SC and Hb SS disease, but still significant 2.
• The hypercoagulable state in SCT may increase the risk of thromboembolism and impact outcomes in multisystem trauma 4, 5.
• More research is needed to fully understand the relationship between SCT and hypercoagulability, particularly in the context of multisystem trauma 5.