Figure 1.

 Antibodies against the NR2A peptide of the glutamate/NMDA receptor in sera of patients with systemic lupus erythematosus (SLE). Sera from 109 SLE patients, 65 patients with myasthenia gravis (MG), 19 patients with autoimmune polyendocrine syndrome type I (APS1), and 65 healthy controls were tested. NR2A specific antibodies were determined by enzyme linked immunosorbent assay (ELISA). Results are expressed as NR2A antibody indices, calculated as described in Methods. The horizontal line represents the upper normal limit (NR2A antibody index of 30) defined as the mean of 65 normal controls +2SD. *p<0.001, **p<0.02.