Identification of psoriasis vulgaris biomarkers in human plasma by non-targeted metabolomics based on UPLC-Q-TOF/MS.

The aim of the study was to investigate the endogenous metabolites of patients with psoriasis vulgaris which will be helpful for the diagnosis of the disease and to provide the evidence of pathogenesis and the formulation for the individualized dosage regimen. This study investigated the plasma metabolomic profiling between the psoriasis vulgaris patients (N=12) and the healthy volunteers (N=12) using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) metabolomic techniques. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to identify and visualize the metabolic data clusters. A total of 22 differential metabolites contributing to the clusters were identified, among which the levels of threonine (p<0.001), leucine (p<0.001), phenylalanine (p<0.001), tryptophan (p=0.018), palmitamide (p<0.001), Linoleic amide (p<0.001), oleamide (p<0.001), stearamide (p<0.001), cis-11- eicosenamide (p< 0.001), trans-13-Docosenamide (p<0.001), uric acid (p=0.034), LysoPC (16:0) (p<0.001), LysoPC (18:3) (p<0.001), LysoPC (18:2) (p=0.024), LysoPC (18:1) (P=0.012) and LysoPC (18:0) (p=0.002) were significantly higher in the plasma of psoriasis vulgaris patients compared with the healthy controls, whereas oleic acid (p<0.001), arachidonic acid (p<0.001) and N-linoleoyl taurine (p<0.001) were significantly lower. These biomarkers are related to glucose metabolism, lipid metabolism, amino acid metabolism, nucleic acid metabolism and so on. The data suggest that psoriasis vulgaris patients may have disrupted lipid and amino acid metabolism, as well as inflammation and functional lesions in the liver and kidney. This study deepens the understanding of psoriasis vulgaris pathogenesis and proposes novel ideas and methods for auxiliary diagnosis and treatment of the disease.