Kynurenine pathway and cytokines leves in adolescentswith major depressive depression

KYNURENINE PATHWAY AND CYTOKINES LEVES IN ADOLESCENTS WITH MAJOR DEPRESSIVE DEPRESSION Aim: The underlying biological mechanisms major depressive disorder are still poorly understood. In this study, we aimed to compare levels of serum kynurenine metabolites (tryptophan, kynurenine, quinolinic acid, kynurenic acid) and IFN-gamma, IL-6, IL-1beta and hsCRP levels in patients with major depressive disorder and healthy controls. It is aimed to evaluate the relationship between cytokine levels and kinurenin pathway activity. Method: Forty-eight patients with major depressive disorder (medication-free) and 31 healthy controls were included in the study. Serum tryptophan, kynurenine, kynurenic acid, quinolinic acid, IFN-gamma, IL-6, IL-1beta levels were measured by enzyme-linked immunosorbent assay (ELISA). hsCRP level was measured by immuno-turbidimetric method. Results: As a result of the comparison between depression and control group; tryptophan levels were significantly lower in patients with depression compared to healthy controls (p = 0.046); KIN / TRP ratio was significantly higher in patients with depression compared to healthy controls (p = 0.032); quinolinic acid levels were significantly higher in patients with depression (p = 0.003); kynurenic acid / quinolinic acid ratio was found to be significantly lower in patients with depression (p = 0.040). There was no significant difference between groups in terms of levels of kynurenine, kynurenic acid, IFN-gamma (p = 0,897), IL-6 (p = 0,086), IL-1beta (p = 0,134) and hsCRP (p = 0,473). Significant negative correlation (r = -0.279, p = 0.016) was detected between IFN-gamma and KIN / TRP ratio. Conclusion: These results suggest that kynurenine and related molecular pathways may be implicated in the pathophysiology of major depressive disorder. More study with the adolescent age group is needed to clarify this relationship. Keywords: tryptophan, kynurenine, kynurenic acid, quinolinic acid, cytokine, adolescent, depression Support: Supported by Scientific Research Projects Commission of Manisa Celal Bayar University (Project no: 2017-092).