Study of anti-cardiolipin and anti-beta2-glycoprotein I antibodies in patients with ischemic stroke.

The study of IgG and IgM anti-cardiolipin antibodies (IgG/IgM aCL) is now well accepted and is routinely used in the risk assessment of various conditions associated with thrombosis. The aim of the study was to define whether the investigation of aCL is sufficient by itself to evaluate a risk of ischemic stroke. Frequency of aCL and anti-beta2-glycoprotein I (beta2-GPI) antibodies was prospectively investigated in 96 patients with ischemic stroke and in 119 controls by ELISA. In ischemic stroke patients IgG aCL were found in 36%, the IgM-aCL were found in 58%, the IgG-IgM-aCL were found in 43%. The levels of both antibodies were higher in patients with ischemic stroke than in controls (p < 0.01). In controls, IgM-aCL were positive in 2% and IgG-aCL antibodies were negative. IgG-beta-GPI Abs were found in ischemic patients in 19% and IgM-beta2-GPI Abs in 37%. The IgG-IgM-anti-beta2-GPI Abs were found in 24% patients. They were negative in controls. There was a correlation between levels of aCL and anti-beta2-GPI Abs for both isotypes (r = 0.728) but not between IgG- and IgM-beta2-GPI Abs. IgG-aCL test was more sensitive for ischemic stroke than the IgG-beta2-GPI Abs test (71.4%, respectively 65.7%) but less specific (66.8%, respectively 88.6%). The sensitivity of anti-beta2-GPI Abs for ischemic stroke was increased when both isotypes were tested. These results showed that aCL and anti-beta2-GPI Abs could be pathogenetically important for ischemic stroke and that anti-beta2-GPI Abs testing might contribute to a better evaluation of ischemic stroke.