Decreased production of interferon alpha and interferon gamma in leucocyte cultures of schizophrenic patients.

In a first approach to measure the activity of the interferon system in schizophrenic patients, leucocyte cultures of schizophrenic patients and normal control individuals were set up using a whole blood assay. In this system both lymphoproliferation and the induction of interferon was tested. The lymphoproliferation (LP) test was performed with one bacterial recall antigen (PPD) and four different mitogens (phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) and a novel mitogen derived from mycoplasma arthritidis - MAS). For induction of interferon two inducers of interferon alpha (Corynebacterium parvum and Newcastle disease virus (NDV] and two inducers of interferon gamma (PHA and Con A) were tested. Leucocytes of the patients responded to C. parvum, NDV and Con A with significantly lower titers of interferon, whereas the responses to PHA were lower than those of normals, but this difference was not significant. Regarding the LP test, significantly lower responses of the patients were obtained with PHA and Con A, whereas there were no significant differences when the responses to MAS, PWM or PPD were compared. Although our data cannot rule out a role of the medications in the defects observed, they may be indicative of a defect in the interferon system of schizophrenic patients.