Characteristics of antineuronal antibodies in systemic lupus erythematosus patients with and without central nervous system involvement: the role of mycobacterial cross-reacting antigens.

Sera of 16 patients with systemic lupus erythematosus (SLE) and active involvement of the CNS were examined for the presence of antibodies to human brain neurons, using indirect immunofluorescence of human brain tissue sections. Thirteen of the 16 patients (81%) had high antineuronal titers, which declined during convalescence, compared with 18 of 105 (17%) SLE patients who had no CNS disease. Competition assays showed that the binding of the antineuronal antibodies was blocked by mycobacterial glycolipids and bovine brain extracts. This finding suggests an additional link between mycobacterial infection and SLE.