Lower serum tropomyosin receptor kinase B levels in patients with schizophrenia.

BACKGROUND Brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) have previously been found to be reduced in the prefrontal cortex of patients with schizophrenia. In this study, we tried to investigate the protein levels of BDNF and TrkB from peripheral blood in the veins of individuals with schizophrenia and health controls. METHODS From January 2008 to November 2010, we recruited 40 schizophrenic patients and 56 healthy controls. Serum BDNF and total TrkB protein levels were detected with enzyme-linked immunosorbent assay (ELISA) kits. Outliners of BDNF and TrkB were excluded initially. Analysis of covariance (ANCOVA) with age adjustment was used for group mean differences of different groups. RESULTS After using the ANCOVA with age adjustment, the results of this work showed that BDNF presented no significant difference (F = 0.065, p = 0.800), but the serum TrkB protein level was significantly lower in schizophrenic patients than in healthy controls (F = 8.34, p = 0.005). CONCLUSION Our findings showed a lower TrkB protein level in serum from schizophrenia patients compared with healthy controls, indicating that the signaling transmission of BDNF/TrkB may be affected in peripheral blood from individuals with schizophrenia.