Differences in the natural autoantibody patterns of patients with schizophrenia and normal individuals.

The expression of IgG and IgM autoantibodies directed against various autoantigens, either part of the central nervous system or not, was investigated in the sera of inpatients with schizophrenia (n = 10). An enzyme immunoassay was used to measure the levels of these autoantibodies in whole sera, IgG-depleted sera, and isolated IgG fractions. IgG and IgM antibodies, reacting with all the antigens tested, were present in the sera of patients with schizophrenia as well as in the sera of normal individuals. Among patients suffering from schizophrenia, IgM natural autoantibody reactivities could be higher (myoglobin, serotonin, tubulin), lower (dopamine), or even identical to those of normal individuals, depending on whether whole or fractionated sera were assayed and on the group of patients with schizophrenia (responders and nonresponders) considered. The isolated IgG fractions of patients suffering from schizophrenia had higher anti-DNA and antiserotonin reactivities than those detected in normal individuals.