Serum profiles of tryptophan-kynurenine pathway metabolites in psoriasis

• DOI: 10.37349/ei.2021.00017
• Publication Date: 2021-09-30T10:16:43Z
• Authors: Mariko Seishima; Yasuko Yamamoto; Masashi Sakurai; Rika Sakai; Kento Fujii; Yoko Mizutani; Kuniaki Saito
• Keywords: Kynurenic acid; Kynurenine pathway; Anthranilic acid

Aim: Chronic inflammation is closely associated with tryptophan (TRP)-kynurenine (KYN) metabolic pathway. However, TRP-KYN pathway has not been fully elucidated in psoriasis, a systemic inflammatory disease skin lesions and extracutaneous manifestations. Herein, we studied comprehensively serum profiles of metabolites psoriatic patients (PSOs) to clarify the involvement this pathophysiology psoriasis evaluate biomarkers reflecting PSOs. Methods: The concentrations main TRP metabolites, TRP, KYN, 3-hydroxykynurenine (3HK), kynurenic acid (KYNA), 3-hydroxyanthranilic (3HAA), anthranilic (AA), were determined by high-performance liquid chromatography sera from 65 PSOs 35 healthy controls (HCs). levels these ratios compared between subjects. correlations values area severity index (PASI) scores analyzed. Skin samples HCs subjected immunohistochemical staining for kynureninase. Cytokine measured same cytokine metabolite examined. Results: Serum KYNA lower 3HAA higher than HCs. 3HK/KYN, 3HAA/3HK, 3HK/AA AA ratio AA/KYN weakly positively correlated, KYNA, 3HK KYNA/KYN 3HAA/AA negatively correlated PASI scores. AA, interferon gamma-induced protein 10 (IP-10) concentrations. Kynureninase expression was enhanced epidermis, both involved uninvolved skin. Conclusions: differed pathway-associated processes, including kynureninase activation, may be pathogenesis thus serve as targets therapy.