Metabolomics approach in the investigation of depression biomarkers in pharmacologically induced immune-related depression.

Background: The aim of this study was to identify previously unrecognised biological pathways and biomarkers that might expand the inflammatory hypothesis of depression.

Methods: Broad metabolomics analyses in plasma samples from 31 chronic hepatitis C-infected patients with and without immune-related depression were carried out using the Absolute IDQ p180 kit-a targeted metabolomics approach of combined direct flow injection and liquid chromatography that measures acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids, and sugars.

Results: The measurements showed that the average concentration of the branched-chain amino acid isoleucine was significantly lower in depressive HCV patients in comparison to non-depressive HCV patients [depression group: Median 51.

Revisiting the tryptophan-serotonin deficiency and the inflammatory hypotheses of major depression in a biopsychosocial approach.

Background: The aim of this cross-sectional study was to identify important biopsychosocial correlates of major depression. Biological mechanisms, including the inflammatory and the tryptophan-serotonin deficiency hypotheses of major depression, were investigated alongside health-related quality of life, life satisfaction, and social support.

Methods: The concentrations of plasma tryptophan, plasma kynurenine, plasma kynurenic acid, serum quinolinic acid, and the tryptophan breakdown to kynurenine were determined alongside health-related quality of life (Medical Outcome Study Form, SF-36), life satisfaction (Life Satisfaction Questionnaire, FLZ), and social support (Social Support Survey, SSS) in 71 depressive patients at the time of their in-patient admittance and 48 healthy controls.

Beta-trace Protein as a new non-invasive immunological Marker for Quinolinic Acid-induced impaired Blood-Brain Barrier Integrity.

Quinolinic acid, a macrophage/microglia-derived excitotoxin fulfills a plethora of functions such as neurotoxin, gliotoxin, and proinflammatory mediator, and it alters the integrity and cohesion of the blood-brain barrier in several pathophysiological states. Beta-trace protein (BTP), a monomeric glycoprotein, is known to indicate cerebrospinal fluid leakage. Thus, the prior aim of this study was to investigate whether BTP might non-invasively indicate quinolinic acid-induced impaired blood-brain barrier integrity.

Quinolinic Acid Responses during Interferon-α-Induced Depressive Symptomatology in Patients with Chronic Hepatitis C Infection - A Novel Aspect for Depression and Inflammatory Hypothesis.

Background: The aim of this exploratory study is to gain for the first time a more comprehensive picture of the impact of changes of quinolinic acid concentrations on depressive symptomatology during and after IFN-α therapy.

Methods: The quinolinic acid concentrations of 35 HCV patients are examined in a prospective survey over the entire period of IFN-α treatment as well as three months later at six different times (baseline, one, three, six and nine months after the beginning of IFN-α treatment, and after the end of treatment).

Results: During IFN-α treatment Hamilton Depression Rating Scale scores rise significantly.

A biopsychosocial model of interferon-alpha-induced depression in patients with chronic hepatitis C infection.

Background: The aim of this prospective study was to gain a more comprehensive picture of the biopsychosocial effects of interferon-α (IFN-α) treatment of patients with chronic hepatitis C (HCV). The predictors of depressive development and changes in health-related quality of life, life satisfaction and cognitive ability were measured with the inclusion of the social context. Furthermore, the effects of IFN-α treatment on indoleamine 2,3-dioxygenase, the level of tryptophan supply in the brain, the development of neurotoxic kynurenine metabolites and the thyroid glands were investigated.