Antiphospholipid antibodies and recurrent thrombosis after a first unprovoked venous thromboembolism

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; P = .09) in the 25.9% of patients with an APA on ≥1 occasions, 2.7 (95% CI, 1.1-.7; P = .03) in the 9.0% of patients with the same APA on 2 occasions, and 4.5 (95% CI, 1.5-13.0; P = .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.

Source: Blood - May 10, 2018 Category: Hematology Authors: Kearon, C., Parpia, S., Spencer, F. A., Baglin, T., Stevens, S. M., Bauer, K. A., Lentz, S. R., Kessler, C. M., Douketis, J. D., Moll, S., Kaatz, S., Schulman, S., Connors, J. M., Ginsberg, J. S., Spadafora, L., Bhagirath, V., Liaw, P. C., Weitz, J. I., J Tags: Thrombosis and Hemostasis, Clinical Trials and Observations Source Type: research