By analyzing patient records collected over a period of 45 years, researchers at the University of Oxford believe that they may have found a link between those suffering from immune diseases such as rheumatoid arthritis and later development or death from VTE conditions including deep vein thrombosis (DVT) and pulmonary embolism (PE).
Researchers examined the medical records of patients with no evidence or history of VTE who had gone into hospital because of their immune-mediated disease. The patients were grouped according to their condition, for example those with Type 1 diabetes, inflammatory bowel disease or systemic lupus. These cohorts were each compared to a reference group of people who had gone into hospital with minor, non-immune-related conditions (broken bones, minor surgical procedures and so on). The researchers looked to see whether the patients in each cohort then developed VTE, and calculated a “rate ratio” that indicated the likelihood of this happening in each cohort within 90 days or after 90 days of initial hospitalization.
Speaking about the results of the study, principal investigator Dr. Michael Goldacre said, “We found significantly elevated rate ratios of VTE in people with certain immune diseases, particularly those with systemic lupus erythematosus and polyarteritis nodosa, but also in a number of other inflammatory diseases. People who have had surgery are at a greater risk of developing VTE anyway, but those with underlying immune conditions seem to have an even higher risk than the general population”.
Though further research is needed to investigate the link between VTE and individual immune disorders, an early explanation for these findings may be that the inflammation caused by the immune response affects the tendency of blood to clot. If this is true, then it may be prudent for certain patients to be given anti-clotting drugs to protect them from VTE while hospitalized.
The paper, entitled 'Risk of venous thromboembolism in people admitted to hospital with selected immune-mediated diseases: record-linkage study', is freely available and can be found online at http://www.biomedcentral.com/bmcmed/