Anti-NMDA receptor antibody positivity in acute psychotic states: An exploratory study

The glutamatergic theory of schizophrenia postulates N-methyl-D-aspartate receptor (NMDA-R) dysfunction. Anti-NMDA receptor antibodies may be present in some patients with psychosis. Fifteen patients presenting with acute psychotic states having one additional clinical feature suggestive of autoimmune etiology were recruited. Serum antibodies against NMDA-receptor were tested at baseline and at follow-up using Indirect Immunofluorescence Technique. None of the 15 patients had positive anti-NMDA antibody at baseline or at follow-up. The study failed to detect anti-NMDA antibodies in patients with acute psychotic states with clinical suspicion of autoimmunity. This does not rule out other mechanisms of NMDA receptor dysfunction in these patients. The glutamatergic theory of schizophrenia postulates N-methyl-D-aspartate receptor (NMDA-R) dysfunction. Anti-NMDA receptor antibodies may be present in some patients with psychosis. Fifteen patients presenting with acute psychotic states having one additional clinical feature suggestive of autoimmune etiology were recruited. Serum antibodies against NMDA-receptor were tested at baseline and at follow-up using Indirect Immunofluorescence Technique. None of the 15 patients had positive anti-NMDA antibody at baseline or at follow-up. The study failed to detect anti-NMDA antibodies in patients with acute psychotic states with clinical suspicion of autoimmunity. This does not rule out other mechanisms of NMDA receptor dysfunction in these patients. •Patients with acute psychosis and features of possible autoimmune etiology were taken.•The serology was negative at baseline and at follow-up after a period of few weeks.•The study does not rule out other possible causes of NMDA-receptor dysfunction.