Tyrosine hydroxylase, interleukin-1β and tumor necrosis factor-α are overexpressed in peripheral blood mononuclear cells from schizophrenia patients as determined by semi-quantitative analysis

The aim of this study is to profile the peripheral biomarkers (tyrosine hydroxylase, TH; interleukin-1β, IL-1β; and tumor necrosis factor-α, TNF-α) for schizophrenia and explore their relations with clinical symptoms. Thirty-nine patients with schizophrenia were evaluated using the Positive and Negative Syndrome Scale (PANSS), and 25 siblings and 30 normal healthy subjects were used as controls. The mRNA expression levels of TH, IL-1β and TNF-α in peripheral blood mononuclear cells, as determined with semi-quantitative reverse transcription-polymerase chain reaction, were all significantly increased in both patients (3-fold) and siblings (2-fold) as compared with normal control. Both IL-1β and TNF-α were significantly correlated with scores on the general psychopathology subscale of the PANSS. A significant positive correlation between IL-1β and TH expression was found in both sibling and normal controls, but not in patients, while a positive correlation between IL-1β and TNF-α was significant in all the groups. These results suggest that TH, IL-1β and TNF-α are overexpressed in the peripheral blood mononuclear cells of schizophrenia patients, perhaps due to the hereditary factors. IL-1β and TNF-α may influence the symptoms of schizophrenia in the cognition dysfunction and anxiety/depression domains of the PANSS.