POS0814 UNTARGETED METABOLOMICS ANALYSIS OF SEBUM: A NON-INVASIVE STRATEGY THAT SHOWS POTENTIAL TO IDENTIFY NEW BIOMARKERS IN PRIMARY SJÖGREN’S SYNDROME AND SYSTEMIC SCLEROSIS

Background Saliva and tears are easy accessible fluids for biomarker analyses but a major drawback is that substantial proportion of patients with primary Sjogren’s syndrome (pSS) suffers from severe dryness, limited or no saliva tear to donate. Thus, novel non-invasive strategies applying state-of-the-art technologies should be welcomed. Objectives To evaluate if metabolome analysis sebum can used as method identify skin metabolic signatures in compared healthy controls other systemic autoimmune diseases. Methods Untargeted metabolomics samples collected sebutapes placed on the forehead 5 minutes was performed using mass spectrometry. Sebum metabolomes (HCs, n=17) 32 pSS were (for this abstract only ions negative ionization mode discussed, positive similar results found). Additionally, two diseases, i.e. sclerosis (SSc, n=21) lupus erythematosus (SLE, n=8), HCs. The human biological sourced ethically their research use accord terms informed consents under an IRB/EC approved protocol. Results Modest significant differences observed between Unsupervised dimensionality reduction UMAP showed strong However, correlation changes disease activity markers did several metabolite good activity. A total 335 significantly correlated European Syndrome Disease index (ESSDAI) score, 13 sIgG 41 lymphocytic focus scores (LFS, all spearman r <-0.50 >0.50, p<0.05). understand pathways activity-associated metabolites may underlie we pathway enrichment investigate potential group function identified these comparisons. Two enriched correlating ESSDAI score: alpha-linolenic acid metabolism phenylalanine metabolism. More robust controls, indicating associated neurotransmission, including annotations L-glutamic acid, noradrenaline, dopamine 3’-AMP. Interestingly, when analyzing differentially expressed SSc relative HCs highly correlations (R=0.78 mode), diseases might have common dissimilarities. Conclusion This pilot study demonstrates strategy biomarkers (systemic) Larger follow-up studies more targeted take into account confounding factors optimize collection demonstrate feasibility monitoring molecular profiling disease. Figure 1. Application collect . All participants avoided facial products 24 hours not wash up 3 prior sample collection. Before participant’s systematically cleaned soap water 2 Sebutape Adhesive Patches collecting applied stored at -80 °C until analyses. REFERENCES: NIL. Acknowledgements: Disclosure Interests None Declared.