Antinuclear antibodies in schizophrenia and major depressive disorder - a lasting puzzle

Sera from patients with major depressive disorder and paranoid schizophrenia were screened for antinuclear antibodies (antigens: ds-DNA, ENA, histone H3) and circulating immune complexes (CIC-Cq1) by ELISA. Controls were healthy blood donors. Only a few of the patients' sera were positive for anti-ds-DNA and anti-ENA antibodies. There was no significant result. In paranoid schizophrenia 20.5% of sera were positive for antibodies against histone H3. In the case of CIC-Cql, 7% of the patients with major depressive disorder and 11 % of those with paranoid schizophrenia were positive. Controls showed positive sera in 39%. This study disagrees with former studies which could demonstrate a series of antinuclear antibodies in mental disorders. In the case of antihistone antibodies, the present results could indicate an autoimmune process in a subgroup of schizophrenic patients.