Kynurenines Metabolites as Biomarkers for Progression in Multiple Sclerosis

Recently, evidence of the association between the kynurenine pathway (KP) and multiple sclerosis (MS) has rapidly grown. The role of KP (major metabolic pathway of tryptophan) was investigated in the pathogenesis of several neurodegenerative, inflammatory, psychiatric, vascular and autoimmune diseases. Stimulation of KP by inflammatory molecules leads to a complex cascade production of neuroactive metabolites. This neuroactive metabolites are known to have different effects on neurons, some being neuroprotective such as kynurenic acid and picolinic acid, while others are neurotoxic like quinolinic acid and 3-hydroxykynurenine. Neurotoxic KP metabolites were associated with the excitotoxicity of oligodendrocytes and neurons that could contribute to the pathogenesis and disease progression of MS by promoting brain cell dysfunction and death.