Altered levels of acute phase proteins in the plasma of patients with schizophrenia.

Schizophrenia is a relatively common psychiatric syndrome that affects virtually all brain functions. We investigated the plasma proteome of 22 schizophrenia male patients and 20 healthy male controls using two-dimensional gel electrophoresis and mass spectrometry. In total, we have identified 66 protein spots in human plasma and found that seven of them showed altered changes in schizophrenia patients, as compared to healthy controls, which mainly were acute phase proteins (APPs). Among these APPs, haptoglobin alpha2 chain (p < 0.001), haptoglobin beta chain (p < 0.001), alpha1-antitrypsin (p = 0.001), and complement factor B precursor (p = 0.022) showed overexpression in schizophrenia patients, whereas apolipoprotein A-I (p = 0.034) and transthyretin (p = 0.035) were found to be significantly decreased in patients. In addition, the expression of apolipoprotein A-IV (p = 0.018) was significantly up-regulated in schizophrenia patients, as compared to controls. We also found these APP genes, which were differentially expressed in this study, overlap in the schizophrenia susceptibility loci. Our findings further support the hypothesis that the inflammatory response system is linked to the pathophysiology of schizophrenia.