A high-risk laboratory profile of antiphospholipid antibodies and thrombosis is associated with a large number of extra-criteria manifestations in obstetric antiphospholipid syndrome.

Extra-criteria manifestations such as thrombocytopenia and livedo are described associated with antiphospholipid syndrome (APS) but are not included in the current classification criteria. Their clinical expression might be important, as they may be associated with a high-risk profile of antiphospholipid antibodies (aPL) and thrombosis. We evaluated the association between the presence of extra-criteria manifestations in primary obstetric-APS (POAPS) and aPL profiles. We also evaluated whether the presence of extra-criteria manifestations in POAPS patients increases the risk of developing thrombosis during the follow-up period (median follow-up 5 years; range 3-9 years). We selected 79 women who were included in our study only if they were first diagnosed with POAPS (with no history of previous thrombosis) and reevaluated for the presence of thrombosis after the follow-up period. We evaluated the association between the aPL profile and extra-criteria manifestations. We also evaluated the relationship of thrombosis during the follow-up period with extra-criteria manifestations and other risk factors. Patients with three or more extra-criteria manifestations presented high rates of triple positivity for the aPL profile (75%) (p < 0.001). We also found a relationship between the presence of extra-criteria manifestations and the presence of high titers of aPL: 91.7% of patients with three or more extra-criteria manifestations had high titers of aPL (p < 0.01). We further evaluated the group of POAPS patients according to thrombotic events during the follow-up. Among these patients, 6 (7.6%) presented thrombosis. Notably, 100% of patients with a thrombotic event during the follow-up had more than three extra-criteria manifestations. POAPS patients with extra-criteria manifestations might have a high-risk aPL profile and a major risk of developing thrombosis.