Antiphosphatidyl serine antibodies are independently associated with ischemic stroke.

OBJECTIVE: To determine whether elevated titers of antiphosphatidyl serine antibodies (aPS) are associated with an increased risk of ischemic stroke in a general stroke population.

BACKGROUND: aPS are members of the family of antiphospholipid antibodies that has been associated with increased stroke risk. Although aPS have been demonstrated to occur in 18% of a group of young patients with cerebrovascular symptoms, their prevalence in the general stroke population is unknown, and no controlled study to assess the strength of their association with ischemic stroke has been undertaken previously.

METHODS: A case-control study comparing 267 acute ischemic stroke patients and 653 community controls. Sera were obtained immediately after acute stroke in patients. Titers of IgG aPS >16 IgG phospholipid units or IgM aPS >22 IgM phospholipid units were considered positive. Odds ratios (ORs) were obtained by logistic regression, adjusting for age, gender, race/ethnicity, history of hypertension, diabetes mellitus, cardiovascular disease, and cigarette smoking.

RESULTS: The adjusted OR was 5.6 (95% confidence interval [CI] 1.8, 18.0) for IgG aPS and 2.9 (95% CI 1.6, 5.3) for IgM aPS. The adjusted OR for either an elevated IgG or IgM aPS was 3.2 (95% CI 1.8, 5.5).

CONCLUSIONS: This study demonstrates that elevated IgG and IgM antiphosphatidyl serine antibodies titers are associated with increased risk of ischemic stroke. The prevalence of these antibodies is lower, but the associated stroke risk is comparable with that of anticardiolipin antibodies.