biostudies-literatureCai ZChina Scholarship CouncilDeutsches Zentrum für Herz-KreislaufforschungChina Postdoctoral Science FoundationCVON12326https://www.ebi.ac.uk/biostudies/studies/S-EPMC9296482biostudies-literatureUnknown12(1)Activation of the kynurenine pathway (KP) has been reported in patients with pulmonary arterial hypertension (PAH) undergoing PAH therapy. We aimed to determine KP-metabolism in treatment-naïve PAH patients, investigate its prognostic values, evaluate the effect of PAH therapy on KP-metabolites and identify cytokines responsible for altered KP-metabolism. KP-metabolite levels were determined in plasma from PAH patients (median follow-up 42 months) and in rats with monocrotaline- and Sugen/hypoxia-induced PH. Blood sampling of PAH patients was performed at the time of diagnosis, six months and one year after PAH therapy. KP activation with lower tryptophan, higher kynurenine (Kyn), 3-hydroxykynurenine (3-HK), quinolinic acid (QA), kynurenic acid (KA), and anthranilic acid was observed in trScientific reportsKynurenine metabolites predict survival in pulmonary arterial hypertension: A role for IL-6/IL-6Rα.PMC92964822017081300772020M680079CVON2014-11, RECONNECT201606230252DZHK81Z0600207Merkus DKlein Tvan den Bosch AEde Rijke YBGeenen LWTu LKema Ivan der Ley CVan Faassen MReiss IKMKoudstaal TGuignabert CCai ZTran-Lundmark KTian SDuncker DJBoomars KABoersma EfalseKynurenine metabolites predict survival in pulmonary arterial hypertension: A role for IL-6/IL-6Rα.Activation of the kynurenine pathway (KP) has been reported in patients with pulmonary arterial hypertension (PAH) undergoing PAH therapy. We aimed to determine KP-metabolism in treatment-naïve PAH patients, investigate its prognostic values, evaluate the effect of PAH therapy on KP-metabolites and identify cytokines responsible for altered KP-metabolism. KP-metabolite levels were determined in plasma from PAH patients (median follow-up 42 months) and in rats with monocrotaline- and Sugen/hypoxia-induced PH. Blood sampling of PAH patients was performed at the time of diagnosis, six months and one year after PAH therapy. KP activation with lower tryptophan, higher kynurenine (Kyn), 3-hydroxykynurenine (3-HK), quinolinic acid (QA), kynurenic acid (KA), and anthranilic acid was observed in tr2022-01-01T00:00:00Z2022 Jul2025-04-25T21:51:24.31Z2025-02-19T03:52:50.035ZS-EPMC92964823585394810.1038/s41598-022-15039-3