Comparing the Metabolic Profile of Patients Affected by Acute-Onset Neuropsychiatric Syndrome PANS and Tourette Syndrome: Preliminary Data

Background: Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) shares numerous clinical features with Tourette syndrome (TS), notably the presence of tics and frequent comorbidities such as obsessive-compulsive disorder, irritability, and ADHD-like behaviors, often indistinguishable, particularly in the early stages of the two syndromes. Also, pathogenic similarities between PANS and TS constitute a diagnostic challenge, highlighting the need for biomarkers elucidating the underpinnings of the two disorders. In this context, metabolomics has emerged as a powerful tool for identifying distinct biochemical patterns in various diseases. We previously compared PANS, autism patients, and controls, identifying specific metabolic patterns. However, no studies have directly compared the metabolomic profiles of Tourette syndrome and PANS patients. The present study aims to compare the serum metabolomic profiles of TS patients with those of PANS and healthy controls to advance the molecular understanding and clinical differentiation of these two pediatric neuropsychiatric disorders. Methods: Thirty-four PANS patients and twenty-three Tourette patients were matched with twenty-five healthy subjects (C), and their blood samples were analyzed with 1H NMR spectroscopy. Subsequently, data were analysed with multivariate and univariate statistical approaches. Results: Supervised models indicated that the metabolomic profile of TS patients was significantly different from that of controls (p = 0.02), with altered concentrations of glutamate, glycerol, glycine, lactate, and proline. No significant differences were found in the comparison between PANS and TS patients. Conclusions: These preliminary data suggest that Tourette and Pans also seem to share the metabolic profiles, while differences were found in TS patients compared to controls. On the other hand, the PANS phenotype comprises symptoms that largely overlap with those of all other NDDs, including TS, outlining a spectrum of disorders that share common pathogenetic pathways. Larger studies are needed to confirm these findings.