High levels of Anti-GAD65 and Anti-Ro52 autoantibodies in a patient with major depressive disorder showing psychomotor disturbance

Abstract

Autoimmune disease and/or autoantibodies have been reported in mood disorder patients. We screened for autoantibodies to glutamic acid decarboxylase (GAD65), thyroid peroxidase (TPO), gastric H+/K+ ATPase (ATP4B), and Ro52 in a psychiatric patient cohort. A 24-year-old woman with major depressive disorder (MDD) with reduced psychomotor activity was identified with unusually high serum GAD65 and Ro52 autoantibody titers. Anti-GAD65 and anti-Ro52 autoantibodies were also elevated in the CSF from this patient. Longitudinal examination revealed a four-fold increase in anti-GAD65 serum antibody titers which correlated with exacerbation of psychomotor symptomatology. These results suggest the possibility that CNS autoimmunity may be responsible for the psychomotor impairment in this MDD patient.

Fig. 1. Identification of a patient with significant autoantibody titers to both Ro52 and GAD65

Forty-four healthy controls (HC; •), 16 patients with bipolar disorder (BD; ▲), 21 currently depressed patients with major depressive disorder (MDD; ■), and 21 patients with major depressive disorder in remission (MDD-R; ▼) were screened for autoantibodies to Ro52 (A) and GAD65 (B) by LIPS. The solid line represents the cut-off level derived from the mean plus 3 SD of the 44 healthy controls, while the dashed line is the cut-off for the mean plus 5 SD. Patient 225, who had the highest autoantibody titers to both antigens, is circled.

Fig. 2. Autoantibody titers in patient 225 increase over time

Autoantibody titers to Ro52, GAD65 and IA2 were measured in patient 225 in April 2004 and again in August 2009. Note that she was seronegative for anti-IA2 autoantibodies in April 2004, but was above the established cutoff and seropositive in August 2009.