Identification of new putative biomarkers for autism in urine by mass spectrometry

Introduction: Autism spectrum disorder (ASD) is characterized by conditions affecting social interaction, communication and behavior, and sensory sensitivity. Studies have reported an association of ASD with various metabolic alterations. The aim of this study was to develop a pilot study of a non-targeted metabolomics and proteomics approach to identify candidate metabolic biomarkers in urine from children with ASD. Material and Methods: Prospective cross-sectional study with case-control design. Cases were male children (n = 22) with ASD, aged 3-10 years, and controls were neurotypical children (n = 22) matched for sex and age. Metabolomic analysis was performed by mass spectrometry with laser desorption ionization and time-of-flight analysis (MALDI-TOF). Proteomic analysis was performed by liquid chromatography coupled to mass spectrometry (LC-MS). Results: Metabolomic analysis identified the 655 mass spectrum with high frequency in the urine samples of both groups, classified as coproporphyrins II and IV. The 1911 Da spectrum showed a higher frequency in urine samples from children with ASD and was classified as GT2 ganglioside (d18:0/14:0). Proteomic analysis also detected the compound with molecular weight of 1911 and its fragments, but they were classified as uromodulins. Conclusion: The non-targeted metabolomic and proteomic approach allowed the identification of promising candidate biomarkers for TEA, although the results of the analyses differed with respect to the nature of the identified compounds.