Nontargeted serum metabolomics analysis and potential biomarkers for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem chronic autoimmune disease characterized by specific clinical and serological changes. Currently, the pathogenesis of SLE remains unclear. This study aimed to identify potential diagnostic biomarkers for SLE and discover the metabolic pathways associated with the disease. We collected serum samples from 260 subjects, including patients with SLE and healthy controls (HCs). Metabolite profiles were analyzed using a nontargeted gas chromatography-mass spectrometry (GC-MS) serum metab-olomics method, and differentially altered metabolites were screened and assessed using univariate and multi-variate analyses. In this study, patients with SLE and HCs were distinguished by 14 significant metabolites. The levels of pipecolinic acid, glutamine, creatine, stearic acid, asparagine and uric acid were increased in serum samples from patients with SLE, whereas levels of allo-inositol, trans-4-hydroxy-L-proline, glycerol-1-phosphate, N-acetyl-L-aspartic acid, malic acid, phosphate, arabitol and ribose were decreased. Arabitol, asparagine and stearic acid were identified as potential biomarkers, and their diagnostic performance was evaluated by per -forming a receiver operating characteristic (ROC) curve analysis. Significantly altered pathways included aspartate metabolism, glycine and serine metabolism, cardiolipin biosynthesis, riboflavin metabolism, plas-malogen synthesis, mitochondrial beta-oxidation of long-chain saturated fatty acids, ammonia recycling, pentose phosphate pathway, arginine and proline metabolism and purine metabolism. By identifying serum biomarkers and analyzing metabolic pathways, our study contributes to a better understanding of the pathogenesis of SLE.