Evaluation of titers of antibodies against peptides of subunits NR1 and NR2B of glutamate receptor by enzyme-linked immunosorbent assay in psychiatric patients with anti-thyroid antibodies

Background: Patients with anti-thyroid antibodies (ATAs) are reported to exhibit atypical psychiatric symptoms. We have been reported that psychiatric patients with ATAs (PPATs) have anti-N-methyl-Daspartate (NMDA) type glutamate receptor (NMDA-R) antibodies by western blot analysis. NMDA-R forms a tetramer with the subunit glutamate receptors (GluR) GluR zeta 1 (NR1) and GluR epsilon 2 (NR2B). However, the possible etiological role of anti-NR1 and anti-NR2B antibodies in PPATs remains unclear. Methods: First, we evaluated titers of anti-NR1 and anti-NR2B antibodies in PPATs by enzyme-linked immunosorbent assay (ELISA). Next, we investigated the relationships among titers of anti-NR1 and anti-NR2B antibodies. Finally, we investigated the relationship between anti-NMDAR antibodies and the psychiatric symptoms in the PPATs. Results: There was a strong correlation between anti-NR1 antibodies and anti-NR2B antibodies in the CSF, and some correlation between these antibodies in the serum. High titers of anti-NR2B antibodies in the serum of PPATs contributed to development of hallucinations and high titers of anti-NR1 antibodies in the serum contributed to development of anxiety by logistic regression. Conclusion: High titers of anti-NR2B antibodies in the serum is a risk factor for hallucinations and high titers of anti-NR1 antibodies in the serum is a risk factor for anxiety in PPATs. (C) 2016 Elsevier Ireland Ltd. All rights reserved.