[Seronegative antiphospholipid syndrome, catastrophic syndrome, new anticoagulants: learning from a difficult case...

The diagnosis of the antiphospholipid syndrome (APS) is based on clinical and biological criteria including the persistent presence of antiphospholipid antibodies and thrombotic events or pregnancy morbidity. Heparins relayed by vitamin K antagonists (VKA) are the gold standard treatment for thrombosis.

We report a 17-year-old man who presented with an initially seronegative antiphospholipid syndrome, in whom the diagnosis was late, only obtained after anticoagulation withdrawing, when a catastrophic antiphospholipid syndrome (CAPS) with cutaneous lesions and disseminated intravascular coagulation syndrome occurred. For personal convenience, this patient was initially treated with fondaparinux followed by a new oral anticoagulant (rivaroxaban) before to return to the conventional VKA treatment.

The "seronegative" APS is a controversial concept reflecting the heterogeneity of antigenic targets for aPL. This diagnosis may be considered after a rigorous work-up, with the help of haemostasis laboratories testing new emerging aPL assays. In APS, the new anticoagulants represent an attractive option needing nevertheless prospective studies to evaluate their safety and efficacy. Lupus anticoagulant detection in patients treated by new oral anticoagulants is not easy by usually recommended coagulation tests.