To Editor: Dr Levine and colleagues1 found that the presence of antiphospholipid antibodies (aPL) among patients with ischemic stroke did not predict an increased risk for subsequent vascular occlusive events. Thus, the authors concluded that routine screening for aPL did not appear warranted for secondary prevention of stroke. These results appear discordant, however, with a previous study by the same authors, which found that presence of anticardiolipin antibodies (aCL) was associated with a higher risk of stroke.2
For several reasons, I doubt that the authors' current results are necessarily applicable to all populations of patients with stroke. First, the mean age of patients in this study was 62.5, similar to that in the authors' prior study.2 This differs substantially from the mean age of 34 years at disease onset in 1000 patients with primary or secondary antiphospholipid syndrome (APS),3 of whom 131 (13.1%) had had a stroke at disease onset, a value that later increased to 20%.3
Second, the authors obtained only a single measurement of aCL and lupus anticoagulant antibodies (LA). Nonetheless, 21% had positive results for aCL, and 13% had positive results for LA. By contrast, 52% of elderly individuals may have positive findings for aCL.4
Third, only 4 of 1770 patients (0.2%) had high IgG aCL levels. Not all of these patients may have been at increased risk, as it appears that the specificity of aCL, particularly anti-β2-glycoprotein I, is related to the risk of thrombosis.5 Indeed, the group of 120 patients who had positive results for both aCL and LA had a tendency to develop more thrombo-occlusive events.1
It is thus possible that in fact the authors studied a group of patients with nonautoimmune thrombo-occlusive events. I disagree with their conclusion that "testing for aCL or LA did not confer important knowledge for prognosis or for treatment, a finding that may apply to the ischemic stroke population in general" (emphasis added).
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
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