Fig. 3
Discovery of the metabolic biomarkers for IgG4-RD. A–C Metabolic biomarkers for IgG4-RD (n = 61) vs HCs (n = 21): A the cumulative AUC of the differently expressed metabolites between IgG4-RD and HCs; B the top 10 metabolites in importance score between IgG4-RD and HCs; C ROC curve of the selected metabolites between IgG4-RD and HCs. M293T419, caftaric acid; M383T459, maltotetraose; M188T358, l-glutamine; M159T438, 3-hydroxyoctanoic acid; M487T411, blood group b trisaccharide; M201T438, 1,6-anhydro-2,3-o-isopropylidene-.beta.-d-mannopyranose; M148T303, d-glutamic acid; M906T194, Pi 40:8; M124T309_2, taurine; M811T197, 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphoserine; M115T338, vitamin c; M221T409, isomaltose; M665T439, fenoxaprop; M362T189, cefadroxil; M329T132, 11beta-hydroxyprogesterone; M162T360_2, carnitine; M185T438, pro-Ala; M123T63, niacinamide; M341T409, d-lactose; M363T304, daunorubicin. D–F Metabolic biomarkers for IgG4-RP (n = 24) vs PC (n = 24): D the cumulative AUC of the differently expressed metabolites between IgG4-RD and PC; E the top 10 metabolites in importance score between IgG4-RP and PC; F ROC curve of the selected metabolites between IgG4-RD and PC. M148T303, d-glutamic acid; M811T197, 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphoserine; M122T304, tris(hydroxymethyl)aminomethane; M779T145, 1-stearoyl-2-myristoyl-sn-glycero-3-phosphocholine; M201T438, 1,6-anhydro-2,3-o-isopropylidene-.beta.-d-mannopyranose; M383T459, maltotetraose; M293T419, caftaric acid; M159T438, 3-hydroxyoctanoic acid; M665T439, fenoxaprop; M839T199, Ps 40:4; M723T147, 1-palmitoyl-2-lauroyl-sn-glycero-3-phosphorylcholine; M191T450, citrate; M177T410, N.omega.-hydroxy-nor-l-arginine; M188T358, l-glutamine; M778T145, 1,2-distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol); M124T309_2, taurine; M116T319_2, l-hydroxyarginine; M807T143, 1-stearoyl-2-palmitoyl-sn-glycero-3-phosphocholine; M795T57, 1-oleoyl-2-palmitoyl-sn-glycero-3-phosphocholine; M162T360_2, Carnitine. G–I Metabolic biomarkers for IgG4-RSD (n = 22) vs SS (n = 22): G the cumulative AUC of the differently expressed metabolites between IgG4-RSD and SS; H the top 10 metabolites in importance score between IgG4-RSD and SS; I ROC curve of the selected metabolites between IgG4-RSD and SS. M132T438, hydroxyproline; M594T171, 2-(5-oxovaleryl)phosphatidylcholine; M127T267, imidazoleacetic acid; M628T190_1, 1-stearoyl-2-arachidonoyl-sn-glycerol; M184T179, 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine; M732T178, N-(octadecanoyl)sphing-4-enine-1-phosphocholine; M704T179, palmitoyl sphingomyelin; M816T176, N-tetracosanoyl-4-sphingenyl-1-o-phosphorylcholine; M496T191, Lpc 16:0; M215T410, (+)-6-aminopenicillanic acid; M116T319_2, l-hydroxyarginine; M177T410, N.omega.-hydroxy-nor-l-arginine; M376T34, tuberostemonine; M213T197, m-chlorohippuric acid; M393T34, chenodeoxycholate; M104T280_2, glycerophosphocholine; M181T384, 3,4-dihydroxyhydrocinnamic acid; M651T410, Caylin-1; M187T315, N-acetylglutamine; M245T195, N-acetyltryptophan; IgG4-RD, immunoglobulin G4-related disease; HC, healthy control; IgG4-RP, IgG4-related pancreatitis; IgG4-RSD, IgG4-related sialadenitis or dacryoadenitis; SS, Sjogren’s syndrome; PC, pancreatic cancer