Inflammation can be acute or chronic. Acute inflammation is caused by a trauma where tissues are damaged allowing microbials (bacterial or virus) to enter the body. This results in a rapid inflammatory response from the immune system, which may last for a few days.

There is a relationship between acute systemic infections and thrombotic events, even without normal cardiovascular risk factors. Viral and bacterial infections have been consistently found to increase risk of myocardial infarction, stroke and venous thromboembolism or VTE (refers to deep vein thrombosis and pulmonary embolism).

Chronic inflammation is a slow, long-term process which may last from many months to years. Diseases associated with chronic inflammation are the highest relevant cause of death in the world. The World Health Organization classifies chronic diseases as the utmost threat to human health.

Chronic inflammation can result from autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. Autoimmune diseases are when the immune system wrongly attacks the body’s own tissues. Immune proteins or autoantibodies harm the body’s own cells rather than foreign invaders.

When autoantibodies attack endothelial cells, a sequence of coagulation reactions occur. Endothelial cells are tissue cells which form the lining of blood vessels and limit clot formation, providing a non-thrombotic surface under normal physiological conditions.

Autoimmune disorders

Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory condition which is also known as an autoimmune disorder. This is when the immune system wrongly attacks the body’s own tissues. This affects not only your joints, but also can cause damage to the skin, heart and blood vessels.

Research has found that there is an increased risk of VTE among RA patients. One nationwide study in Sweden discovered that there was nearly double the risk of VTE among patients with RA compared to the general population. Patients which had both active RA, and their condition was in remission, still had the same high risk of VTE.

Systemic lupus erythematosus and antiphospholipid syndrome

Systemic lupus erythematosus (SLE) or ‘lupus’ is an acquired autoimmune disease where the immune system attacks its own tissues causing chronic inflammation, affecting several organs in the body. Having SLE presents as a risk factor for both arterial and venous thrombosis.

The risk of developing thrombotic events increases even more when SLE is associated with other factors linked with either inherited or acquired pro-thrombotic situations or triggers, such as antiphospholipid antibodies (aPLs) or syndrome (APS). SLE and APS are constantly examined together and identified as two closely related diseases as approximately 50% of SLE patients will have aPLs present, however around 20% of APS patients have SLE. You can read more on our webpages - SLE & APS.           (Image:The Lancet-Antiphospholipid syndrome)

Atopic dermatitis

Atopic dermatitis (AD) or eczema is a chronic inflammatory disease and some studies have found that it is associated with an increased risk of VTE. The research presented data showing a higher risk for deep vein thrombosis, however not for pulmonary embolism. Patients with AD who also were older or obese were more vulnerable to thrombosis.

Thrombophlebitis

Thrombophlebitis is an inflammatory process which causes a clot to form and block a vein, typically in the legs. If the clot is near the surface of the skin, it is called ‘superficial thrombophlebitis’ or ‘superficial vein thrombosis’ (SVT). Deeper under the skin, within a muscle it is the common term known as DVT (deep vein thrombosis).

Causes of thrombophlebitis include extended periods of inactivity, trauma or surgery. Research has shown that there is a possibility that SVT can be linked with DVT in 6-40% of cases, with asymptomatic pulmonary embolism (PE) in 20-30%, and symptomatic PE in 2-13%.

Chronic obstructive pulmonary disease (COPD)

This is an obstructive lung disease which develops in response to inhaled irritants or persistent restricted airflow. This condition is categorised as the 5th main cause of death worldwide. A population-based retrospective study in 2020 found that 12.3 out of 10,000 COPD patients developed pulmonary embolism (PE) on a yearly basis, which was almost four times higher than patients without COPD. Research has also found that the higher the extent of airway obstruction with COPD, the increased risk of VTE.

COPD patients frequently develop coagulation dysfunction due to certain mechanisms such as systemic inflammation, oxidative stress, defective endothelial and hypercoagulability, which may increase the risk of thromboembolism. There are some inflammatory markers in the serum of COPD patients, like cytokines which can activate the coagulation cascade.

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References

• Bazzan, M., Vaccarino, A., & Marletto, F. (2015). Systemic lupus erythematosus and thrombosis. Thrombosis Journal, 13.1.
• Bertoletti, L. & Couturaud, F. (2021). COPD is not only one of the several VTE risk factors. European Journal of Internal Medicine 84: 14–15.
• Yang, R., Guiqing, L., & Chaosheng, D. (2021). Pulmonary embolism with chronic obstructive pulmonary disease. Chronic Diseases and Translational Medicine 7.3: 149–156.
• de Almeida, Marcelo José et al. (2019). Guidelines for Superficial Venous Thrombosis.” Jornal vascular brasileiro 18: e20180105–e20180105.
• Hong, C. & Chih-Hung, L. (2023). A nationwide UK cohort study reveals an association between atopic dermatitis and venous thromboembolism.” British journal of dermatology (1951).
• Merola, J.F. et al. (2023). Comparative risk of venous thromboembolism (VTE) among patients with atopic dermatitis (AD) or other immune-mediated diseases: a cohort study using United States Claims Data. British journal of dermatology (1951) 188.Supplement_2.
• Molander, V. et al. (2021). Risk of venous thromboembolism in rheumatoid arthritis, and its association with disease activity: a nationwide cohort study from Sweden.” Annals of the rheumatic diseases 80.2: 169–175.
• Yuan, W., & Guan, F. (2022). Thrombosis and anticoagulation therapy in systemic lupus erythematosus. Autoimmune diseases.
• Thrombophlebitis - Symptoms & causes - Mayo Clinic
• Chronic Inflammation - PubMed (nih.gov)
• Chronic Inflammation - StatPearls - NCBI Bookshelf (nih.gov)
• Rheumatoid arthritis - Symptoms and causes - Mayo Clinic