Effects of depression on the cytokine profile in drug naive first-episode psychosis

Schizophrenia is accompanied by alterations in immuno-inflammatory pathways, including abnormalities in cytokine profile. The immune assessment of patients in a first episode of psychosis (FEP) and particularly in drug naive patients is very important to further elucidate this association. The objectives of this study are to delineate the cytokine profile (IL-2, IL-10, IL-4, IL-6, IFN gamma, TNF alpha and IL-17) in FEP patients (n = 55) versus healthy controls (n = 57) and to examine whether the presence of depressive symptoms in FEP is accompanied by a specific cytokine profile. We found increased levels of IL-6, IL-10 and TNFa in FEP patients when compared to healthy controls. FEP patients with depression showed higher IL-4 and TNFa levels versus those without depression. Cytokine levels were not correlated to the total PANSS and the positive or negative subscale scores. Our results suggest that FEP is accompanied by a cytokine profile indicative of monocytic and T regulatory cell (Treg) activation. Depression in FEP is accompanied by monocytic and Th-2 activation, whereas FEP without depression is characterized by Treg activation only. In conclusion, depression emerged as a key component explaining the cytokines imbalance in FEP that is responsible for a large part of the immune-inflammatory abnormalities described. (C) 2015 Elsevier B.V. All rights reserved.