Correlation of aggression with serum IgM level in autoimmune-prone NZB mice

Neurological symptoms are often found in patients with systemic lupus erythematosus, an autoimmune disease. We found an enhanced aggression in young autoimmune-prone NZB mice before expression of autoimmune hemolytic anemia, which was accompanied by an increase in neural activity in the accessory olfactory bulb. The performance of aggressive behavior was correlated with serum IgM level. These results indicate that IgM class autoantibodies could be implicated in brain dysfunction without apparent pathological changes of autoimmune disease.