Sjögren's Syndrome (SjS) is a complex autoimmune disease characterized by the affection
of the exocrine glands and the involvement of multiple organs. Although a greater
number of biomarker studies have been carried out in recent years, the origin and
pathogenesis are not yet well known and therefore there is a need to continue studying
this pathology. This work aims to find metabolic changes in biological samples (plasma
and urine), which could help identify the metabolic pathways affected by the SjS pathogenesis.
The samples collected from SjS patients and healthy volunteers were analyzed by a
fingerprinting metabolomic approach based on HPLC-ESI-QTOF-MS methodology. After feature
pre-selection by univariate statistical tests, an integrated PLS-DA model using data
from urine and plasma was constructed obtaining a good classification between cases
and controls (AUROC = 0.839 ± 0.021). 31 and 38 metabolites in plasma and urine, respectively,
showed significant differences between healthy volunteers and SjS patients and were
proposed for their identification. From them, 12 plasma and 24 urinary metabolites
could be annotated. In general, the main metabolic pathways altered in SjS patients
were related to the metabolism of phospholipids, fatty acids, and amino acids, specially
tryptophan, proline and phenylalanine.