Objective: To determine whether elevated titers of antiphosphatidyl serine
antibodies (aPS) are associated with an increased risk of ischemic stroke i
n 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 yo
ung patients with cerebrovascular symptoms, their prevalence in the general
stroke population is unknown, and no controlled study to assess the streng
th of their association with ischemic stroke has been undertaken previously
. Methods: A case-control study comparing 267 acute ischemic stroke patient
s and 653 community controls. Sera were obtained immediately after acute st
roke 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 ci
garette 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 adju
sted OR for either an elevated IgG or IgM aPS was 3.2 (95% CI 1.8, 5.5). Co
nclusions: This study demonstrates that elevated IgG and IgM antiphosphatid
yl serine antibodies titers are associated with increased risk of ischemic
stroke. The prevalence of these antibodies is lower, but the associated str
oke risk is comparable with that of anticardiolipin antibodies.