Some cases of schizophrenia linked to an autoimmune reaction

Cell Reports Medicine: Anti-NCAM1 autoantibodies cause symptoms of schizophrenia

Scientists at the Tokyo Medical and Dental University have found specific autoantibodies in some patients with schizophrenia. The results of the work, published in the journal Cell Reports Medicine, suggest that a severe mental disorder may be associated with an autoimmune response of the body.

shyza243b1850Previous studies have shown that the neural cell adhesion molecule (NCAM1), which provides mechanical interaction between neurons and synapses, may be involved in the development of schizophrenia. Scientists searched for autoantibodies against NCAM1 in 200 healthy people and 200 patients with mental illness. Autoantibodies are molecules that cause an aggressive response of the immune system against the cells and tissues of one’s own body.

Autoantibodies were found in only 12 patients with schizophrenia, suggesting that a small subset of schizophrenia cases may be autoimmune in nature. To confirm the role of autoimmune reactions, the researchers isolated autoantibodies and injected them into the cerebrospinal fluid of mice. Even though these molecules were present in the central nervous system of rodents for a short time, the animals showed marked changes in synapse function and behavior in general. These symptoms were similar to those seen in people with schizophrenia.

In particular, mice with autoantibodies had cognitive impairments and changes in the startle reflex response, which are also seen in other animal models of schizophrenia. The rodents also had a decrease in the number of synapses and dendritic spines, which are structures important for connections between neurons.

According to the authors of the study, if it is confirmed that in some patients schizophrenia is indeed caused by autoantibodies against NCAM1, this could lead to improvements in the diagnosis and treatment of this type of disorder.