Identification\nof Plasma Metabolites and Dipeptides\nas Diagnostic Biomarkers for Psoriasis Vulgaris through Liquid Chromatography-High\nResolution Mass Spectrometry-Based Metabolomics

Psoriasis, an immune-mediated chronic inflammatory skin\ndisease,\nis primarily diagnosed through clinical assessment. Currently, specific\nmarkers for the accurate diagnosis and prediction of psoriatic disease\nare lacking. Here, we employed a three-step designed study to perform\nuntargeted metabolomics, with the aim of identifying candidate biomarkers\nfor psoriasis. Through comprehensive multivariate and univariate statistical\nanalyses, we screened eight potential biomarkers specific to psoriasis,\nwith five structurally identified. Two dipeptide biomarkers, γ-GluSer\nand ThrGly, along with a lysine glycation metabolite, <i>N</i>α-fructosyl-lysine (Fruc-Lys), were found to be psoriasis biomarkers\nfor the first time. Receiver operating characteristic curve analysis\nrevealed that the area under the curve (AUC) values of these eight\nmetabolites/features ranged from 0.68 to 0.94. A biomarker panel comprising\nThrGly and feature <i>m</i>/<i>z</i> 120.0656\n(C<sub>4</sub>H<sub>9</sub>NO<sub>3</sub>) demonstrated high diagnostic\naccuracy (AUC = 0.97) in distinguishing psoriasis patients from healthy\ncontrols. Overall, our study identified and validated a panel of plasma\nmetabolites/features that could serve as potential biomarkers for\nthe diagnosis of psoriasis, providing new insights into the diagnosis\nand pathogenesis of this disease.