Anti-neuronal antibodies in antiphospholipid syndrome with central nervous system involvement: the difference from systemic lupus erythematosus.

The presence of antineuronal antibodies was compared in 43 patients with primary aPLS and 57 patients with neuropsychiatric SLE. Fifty-eight patients with Guillain-Barré syndrome and 72 normal healthy donors served as control groups. Seventeen patients in the study group had aPLS associated with CNS involvement. Antineuronal antibodies were studied in the sera employing a novel flow cytometric assay. The frequency of antineuronal antibodies in patients with aPLS and CNS involvement was not significantly different from that of patients with aPLS without CNS disease or from that found in the control groups (12%, 19% and 7%, respectively). However, it was significantly different from that found in SLE patients with CNS involvement (60%) (P < 0.001). Our results provide further evidence that unlike CNS-SLE, the major mechanism of CNS involvement in patients with primary aPLS might not be autoantibody (antineuronal) mediated, but rather 'thrombotic' in origin, or due to yet unknown factors.