Nuclear Magnetic Resonance Spectroscopic Analysis of Urinary Metabolome in Sarcoidosis

"Sarcoidosis is a systemic granulomatous disease of unknown cause(s) with an almost constant lung involvement. Clinical expression varies greatly in both evolution and severity. The activity of the disease is currently based on serum markers (elevation of angiotensin-converting enzyme) with poor sensitivity/specificity or on imaging techniques (18F-FDG PET-CT) which are more invasive and more expensive. Determining disease activity is a major element in the treatment decision.

The spectra of small molecules resulting from metabolism (metabolome/metabolomics) evaluated by spectrometry in different biological fluids (blood, saliva, urine) during different physiological or pathological conditions have been identified as promising biomarkers. 1H- Nuclear magnetic resonance (NMR) spectrometry allows the identification of biomarkers in different pathologies and in particular in a pilot study of saliva of patients with sarcoidosis. Applications to sarcoidosis are still rare having concerned only serum and saliva. The application of this method to the urinary metabolome has shown its effectiveness in other situations, for example in celiac disease.

In this context we hypothesize the existence of a difference in the metabolic products found in the urine of sarcoidosis patients with different degrees of activity and/or disease severity.

We designed an analysis of urinary metabolomics in sarcoidosis patient using NMR spectroscopy with multivariate statistical analysis, followed by metabolite identification and pathway analysis. "