Biosignatures for Fatigue Syndromes

An in vitro method for measuring, predicting, diagnosing, prognosing and/or monitoring chronic mental stress in a sample obtained from a subject, comprising detecting at least three biomarkers independently selected from at least three different groups of biomarkers selected from:

• i. a group of immune function biomarkers consisting of neopterin, secretory immunoglobulin A (sIgA), interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin-1 receptor A (IL-1RA), epidermal growth factor (EGF), leukocytes, neutrophils, lymphocytes, monocytes, basophils, C-reactive protein (CRP) and myeloperoxidase (MPO);
• ii. a group of iron metabolism biomarkers consisting of ferritin, transferrin, iron, transferrin saturation, hemoglobin in reticulocytes, erythrocytes, mean cell haemoglobin (MCH), mean cell volume (MCV), mean cell haemoglobin concentration (MCHC) and reticulocytes;
• iii. a group of metabolism biomarkers consisting of creatinine, urea, vitamin D, folic acid, riboflavin, vitamin B12, 4-pyridoxic acid, flavin mononucleotide, thiamine, nicotinamide, pyridoxal 5′-phosphate, N1-methylnicotinamide, trigonelline, thiamine monophosphate, and visfatin;
• iv. a group of steroid hormone biomarkers consisting of dehydroepiandrosterone sulfate (DHEA-S), sex hormone binding globulin (SHBG), bio-available testosterone, total testosterone, free testosterone, and dehydroepiandrosterone (DHEA);
• and
• iv. a group of sympathetic adrenal medullary axis biomarkers consisting of amylase, epinephrine, and norepinephrine, preferably wherein amylase is alpha-amylase;
• and
• vi. optionally a group of neurotransmitter biomarkers consisting of anthranilic acid, cystathionine, picolinic acid, kynurenic acid (KYNA), L-kynurenine, quinolinic acid (QUIN), free tryptophan, xanthurenic acid, brain-derived neurotrophic factor (BDNF), S100 calcium-binding protein B (S100B), and γ-aminobutyric acid (GABA);
• wherein the chronic mental stress is the mental status prior to development of mood disorders, such as depression or burn-out.