Antiphospholipid antibodies and recurrent thrombosis after a first unprovoked venous thromboembolism

Abstract

It is uncertain whether antiphospholipid antibodies (APAs) increase the risk of recurrence after a first unprovoked venous thromboembolism (VTE). We tested for anticardiolipin antibodies, anti-β2 glycoprotein 1 antibodies, and lupus anticoagulant on 2 occasions ∼6 months apart in 307 patients with a first unprovoked VTE who were part of a prospective cohort study. We then determined if APAs were associated with recurrent thrombosis in the 290 patients who stopped anticoagulant therapy in response to negative D-dimer results. Compared with those without an APA, the hazard ratios for recurrent VTE were 1.8 (95% confidence interval [CI], 0.9-3.7; = .09) in the 25.9% of patients with an APA on ≥1 occasions, 2.7 (95% CI, 1.1-.7; = .03) in the 9.0% of patients with the same APA on 2 occasions, and 4.5 (95% CI, 1.5-13.0; = .006) in the 3.8% of patients with 2 or 3 different APA types on either the same or different occasions. There was no association between having an APA and D-dimer levels. We conclude that having the same type of APA on 2 occasions or having>1 type of APA on the same or different occasions is associated with recurrent thrombosis in patients with a first unprovoked VTE who stop anticoagulant therapy in response to negative D-dimer tests. APA and D-dimer levels seem to be independent predictors of recurrence in patients with an unprovoked VTE. This trial was registered at www.clinicaltrials.gov as #NCT00720915.

Prevalence of confirmed antiphospholipid syndrome in 18‐50 years unselected patients with first unprovoked venous thromboembolism

“…In two VTE randomized trials, APS prevalence was 9%, 19,20 which was close to our observation. Patients included in these trials had a first unprovoked VTE and were treated with vitamin K antagonists (VKA) for 6 months.…”

“…Most recent studies included 98 to 371 patients with unprovoked VTE regardless of age. 16,19,22 In conclusion, APS prevalence was 9% among tested patients…”

“…First, to the best of our knowledge, we report on one of the largest series of first unprovoked VTE patients from the community and younger than 50 years. Most recent studies included 98 to 371 patients with unprovoked VTE regardless of age . In 1997, Mateo et al reported on a cohort of 2132 VTE patients of all ages without stratifying antiphospholipid antibody prevalence on VTE risk factors .…”

Dilute Russell viper venom time interpretation and clinical correlation: A two‐year retrospective institutional review

“…Patients with positivity in both the dRVVT and Staclot-LA were fairly likely to receive an APS diagnosis,while patients tested with both assays but with only one positive result were rarely diagnosed. This finding is similar to that described by Kearon et al,15 where those venous thrombo-embolism (VTE) patients with more than one antiphospholipid antibody detected on either the same or different occasions showed the highest level of risk of recurrent VTE.…”

Use of D‐dimer in oral anticoagulation therapy

“…40 Recently, Kearon et al found that patients with a first unprovoked VTE who had antiphospholipid antibodies still suffer a high risk of subsequent recurrence even after anticoagulant therapy was stopped in response to negative D-dimer tests. 41 All the findings mentioned above indicate that VTE recurrence is associated with multiple factors, and many potential factors are still unsettled, which still need to be clarified in future studies. Thus, guidelines have not made recommendations based on these uncertain factors.…”