Immunological Disturbances in Psychiatric Patients-Reply

n Reply.—  Our recent study¹ showed no elevation of immunoglobulin levels or increased incidence of oligoclonal immunoglobulin in a group of psychiatric patients compared with controls. Although these data suggest that viruses and autoimmunity are not involved in the major psychoses, the study has certain limitations that are detailed in our article and reiterated in Dr DeLisi's letter. Most individuals with persistent CNS infections have raised cerebrospinal fluid (CSF) immunoglobulin levels, but immunosuppressed individuals may have chronic viral infections with little evidence of immunoglobulin level elevations. In addition, unconventional agents and autoimmune processes may not produce quantitative or qualitative immunoglobulin abnormalities. Most investigators have found, however, that CSF immunoglobulin level elevations and bands have been found consistently in persistent viral encephalitis caused by conventional agents in immunocompetent hosts, eg, 100% of patients with subacute sclerosing panencephalitis and herpes simplex encephalitis^2,3 have increased CSF IgG levels and bands.⁴