Thromboembolic Disease

Key considerations for people living with HIV

There is an increasing body of evidence to suggest that HIV infection may be associated with a hypercoagulable state. Therefore, people living with HIV (PLWHIV) are at increased risk of developing clinically detectable thromboembolic disease compared with the general population.^1,2

• 
In otherwise healthy individuals, a thrombus can be formed in response to a damaged blood vessel (induced by trauma, surgery or atherosclerosis), inadequate blood flow or clotting abnormalities. A thrombus can subsequently embolize, obstructing blood flow either locally or elsewhere in the body.
• When a thrombus occupies a significant proportion of the lumen of an artery or vein, blood flow is often reduced sufficiently to cause clinical symptoms and/or a number of serious complications. Major occlusion can result in ischemia and tissue infarction, which may lead to death.
   

PLWHIV often present with thromboembolic diseases, despite displaying few of the classical risk factors (such as trauma or surgery). Such patients may therefore have an increased requirement for pharmacological and/or mechanical prophylaxis.

A number of abnormalities have been observed in PLWHIV that may contribute to an increased risk of thrombus formation:³

• the presence of antiphospholipid antibodies and the lupus anticoagulant
• deficiencies of protein C, protein S, heparin cofactor II and antithrombin
• increased levels of von Willebrand factor and D-dimers
• increased levels of adhesion molecules (e.g. ICAM)⁴
   

References

1. Malek J, Rogers R, Kufera J, Hirshon JM. Venous thromboembolic disease in the HIV-infected patient. Am J Emerg Med. 2011;29(3):278–282. 
2. Rasmussen L, Dybdal M, Gerstoft J, et al. HIV and risk of venous thromboembolism: a Danish nationwide population-based cohort study. HIV Med. 2011;12(4):202–210. 
3. Saif MW. Thromboembolism associated with HIV infection: a case report and review of the literature. AIDS Read. 2000;10(8):492–496.
4. Mu H, Chai H, Lin PH, Yao Q, Chen C. Current update on HIV-associated vascular disease and endothelial dysfunction. World J Surg. 2007;31(4):632-643.