Fourier-transform infrared spectroscopy discriminates a spectral signature of endometriosis independent of inter-individual variation

摘要

Endometriosis is the growth of endometrial tissue outside of the uterine cavity. Its aetiology remainsnobscure, and it is difficult to diagnose ranging from asymptomatic to debilitating disease. Mid-infraredn(IR) spectroscopy has become recognised as a potential clinical diagnostic tool. Biomolecules absorbnmid-IR (4000 cmu00021 to 400 cmu00021) and from this, a biochemical-cell fingerprint in the form of annabsorbance spectrum can be derived. We set out to determine if IR spectroscopy could be used tonidentify underlying biochemical differences between endometrial tissues growing outside of the uterusn(ectopic) from endometrial tissue of the uterus (eutopic). For comparative purposes, endometrialntissues from endometriosis-free women were also obtained (benign eutopic). Attenuated total reflectionnFourier-transform IR (ATR-FTIR) spectroscopy or transmission FTIR microspectroscopy wasnemployed for spectral acquisition. Principal component analysis (PCA)-linear discriminant analysisn(LDA) was used for chemometric analysis. A clear segregation was exhibited between the threencategories independent of inter-individual confounding differences. Importantly, there was a markedndifference between eutopic endometrial tissue from patients with or without endometriosis. Thisnindicates that IR spectroscopy coupled with multivariate analysis (e.g., PCA-LDA) may providena non-invasive diagnostic tool for endometriosis. By analysing the underlying biochemistry of thesenendometrial tissues, this approach may facilitate a better understanding of this pathology.