Aregger F, et al. - Researchers analyzed metabolites of a conserved key inflammatory pathway (i.e. tryptophan degradation pathway) in serial urine samples of patients with acute kidney injury (AKI) in order to gain insight into non-recovery from AKI in critically ill patients. They found that in critically ill patients with AKI, increased urinary levels of kynurenic acid, a key inflammatory metabolite of the tryprophan degradation pathway, were associated with adverse renal and clinical outcomes. Additionally, they noted that urinary kynurenic acid (KynA) may serve as an early risk stratificator in respective patients with AKI.