Schizophrenia is associated with increased levels of serum Fas and FasL

Background: A growing body of evidence suggests that the apoptotic process is dysregulated in schizophrenia. However, only a few studies have evaluated apoptotic markers in vivo in patients or their cell cultures. Methods: Serum concentrations of Fas receptor (Fas/APO-1) and Fas ligand (FasL) were measured by ELISA techniques. The differences were tested according to the patients' demographic, clinical and drug treatment characteristics. The clinical accuracy of the examined markers was assessed using receiver operating characteristic (ROC) curve analysis. Results: In this case-controlled study both sFas/APO-1 and FasL were significantly higher in the patients with schizophrenia than in the controls. An increase in apoptotic markers was independent of the symptomatology, drug treatment, heredity, the first onset of the disease, the duration of the psychotic disease as well as the tobacco abuse. A significant negative correlation between the duration of the disease and sFasL concentration was found. At the same time, a significant positive correlation was found between sFasL and lymphocyte caspase-3 activity. ROC curve analysis showed that sFasL was the most strongly associated with the presence of schizophrenia. Conclusions: We can conclude that the extrinsic apoptotic pathway is dysregulated in schizophrenia and sFasL may be a clinically useful disease predictor.