Application of metabolomics in autoimmune diseases: Insight into biomarkers and pathology

• Metabolic profiling is extremely useful for identifying biomarkers.
• Metabolic profiling discriminates between autoimmune diseases and healthy subjects.
• Biomarkers identified in autoimmune diseases involve many pathways.
• The well-established technique for metabolomics includes NMR and MS.

Metabolomics has recently become a new technology using mass spectrometry (MS) and high-resolution proton nuclear magnetic resonance (NMR) to access metabolite profiles in biofluids or tissue extracts for the detection of biomarker molecules and biochemical effects induced by a disease or its therapeutic intervention. This review outlines recent advances in the use of metabolomic techniques to study autoimmune diseases (ADs), including multiple sclerosis (MS), rheumatoid arthritis (RA), inflammatory bowel diseases (IBD), autoimmune diabetes et al. Many studies have demonstrated that AD patients including subtypes of some diseases, and healthy individuals can be distinguished using metabolic profiling accompanied with well-established data analysis tools including principal component analysis (PCA) and partial least squares (PLS). These metabolites not only affect glucose, amino acid and lipid metabolism, but also involve alteration of neurotransmitters, nucleotides, immune responses and anti-inflammatory responses. Knowledge of unique metabolomic fingerprint in ADs could be useful for diagnosis, treatment, and detection mechanisms of diseases.