Indoleamine 2,3-dioxygenase and Immune Changes Under Antidepressive Treatment in Major Depression in Females

摘要

Background/Aim: Indoleamine 2, 3-dioxygenase (IDO) induction has been suggested as a mechanism by which immune activation affects tryptophan metabolism and serotonin synthesis in major depressive disorder (MDD). We investigated IDO and changes in inflammatory mediators in patients with MDD undergoing effective treatment. Patients and Methods: Forty female patients with MDD and 40 controls were recruited. Serum IDO was assessed by enzyme-linked immunosorbent assay (ELISA). We also determined tumor necrosis factor- (TNF), interferon-{gamma} (IFN{gamma}), C-reactive protein (CRP) and serotonin concentrations. Results: Patients' baseline concentrations of IDO and immune mediators were higher and serotonin concentrations were lower compared to controls. IDO and TNF concentrations decreased under treatment and IDO changes were positively correlated with patient improvement. IFN{gamma} and CRP concentrations remained unchanged. Serotonin concentration tended to increase. Conclusion: IDO might play an important role in the pathophysiology of MDD. Moreover, antidepressant therapy might reduce IDO production through an IFN{gamma}-independent pathway. Finally, peripheral concentration of IDO assessed by ELISA might be a useful marker of MDD.