Study of antiphospholipid antibodies in patients treated with antiepileptic drugs

Antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies) are associated with a variety of clinical situations, including drug-intake, but their relationships with antiepileptic drugs have been scarcely investigated.

To determine the prevalence of antiphospholipid antibodies in patients treated with antiepileptic drugs and the associated risk of thrombotic events.

We performed the serologic study of thirty-six consecutively prospectively recruited epileptic patients treated with diverse antiepileptic drugs during 44.38 +/- 8.08 months (mean +/- SD) in which antiphospholipid antibodies were determined using cardiolipin and a mixture of phospholipid from rabbit brain as antigen for detection of cardiolipin and lupus anticoagulant by ELISA and in addition lupus anticoagulant was carried out also using coagulometric assays. A clinical evaluation was done in order to determine the presence of thrombotic events in the following five years.

Antiphospholipid antibodies were detected in 43% of these patients, in most of them as anticardiolipin antibodies (IgM subtype). The patients did not present thrombotic events during the time of the study.

Antiphospholipid antibodies are positive in a high proportion of these patients but thrombosis were not found during the study duration. This may be explained by the fact that the profile of aCL positivity not associated to positive LA observed in these patients does not confer a risk for thrombotic events.