AB Background: An autoimmune hypothesis has been suggested for a subtype of Obsessive-Compulsive Disorder (OCD); this hypothesis was investigated particularly in children, while only two studies assessed samples of adult patients. Aim of the study: To evaluate in a sample of adult OCD patients: a) the proportion of subjects with antibodies directed towards neuronal structures; b) with high ASLO titers and/or with markers of autoimmunity measured in the practice of neurology and internal medicine. Materials and methods: 74 OCD patients consecutively referred to the Mood and Anxiety Disorders Unit, Department of Neuroscience, University of Turin were recruited; as control group, 44 patients with a current major depressive episode consecutively referred to the same Unit were recruited. Structured and semi-structured interviews were used to collect data. Anti-brain antibodies were tested by immunohistochemistry and western-blotting methods. Results: 5.4% of the OCD sample resulted positive for anti-brain antibodies and there was an association with an earlier onset of symptoms. 10.3% of OCD subjects had high mean ASLO titers and this was correlated with a pre-pubertal onset of symptoms. No other significant differences in antibody parameters were found. Conclusions: In a small proportion of OCD patients autoimmune reactions towards neuronal structures are present. Further investigations are needed to demonstrate a possible autoimmune etiopathogenesis in this subtype of OCD, in order to open new therapeutic scenarios.
