Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Monroe Carell Jr. Children's Hospital at Vanderbilt, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Vanderbilt Biophotonics Center, Department of Biomedical Engineering, Vanderbilt University, Tennessee, USA.
Clin Transl Gastroenterol. 2020 Jul;11(7):e00195. doi: 10.14309/ctg.0000000000000195.
Elucidating esophageal biochemical composition in eosinophilic esophagitis (EoE) can offer novel insights into its pathogenesis, which remains unclear. Using Raman spectroscopy, we profiled and compared the biochemical composition of esophageal samples obtained from children with active (aEoE) and inactive EoE (iEoE) with non-EoE controls, examined the relationship between spectral markers and validated EoE activity indices.
In vitro Raman spectra from children with aEoE (n = 8; spectra = 51) and iEoE (n = 6; spectra = 48) and from non-EoE controls (n = 10; spectra = 75) were acquired. Mann-Whitney test was used to assess the differences in their Raman intensities (median [interquartile range]) and identify spectral markers. Spearman correlation was used to evaluate the relationship between spectral markers and endoscopic and histologic activity indices.
Raman peaks attributable to glycogen content (936/1,449 cm) was lower in children with aEoE (0.20 [0.18-0.21]) compared with that in non-EoE controls (0.24 [0.23-0.29]). Raman intensity of proteins (1,660/1,209 cm) was higher in children with aEoE compared with that in non-EoE controls (3.20 [3.07-3.50] vs 2.91 [2.59-3.05]; P = 0.01), whereas that of lipids (1,301/1,260 cm) was higher in children with iEoE (1.56 [1.49-1.63]) compared with children with aEoE (1.40 [1.30-1.48]; P = 0.02). Raman peaks attributable to glycogen and lipid inversely correlated with eosinophilic inflammation and basal zone hyperplasia. Raman mapping substantiated our findings.
This is the first study to identify spectral traits of the esophageal samples related to EoE activity and tissue pathology and to profile tissue-level biochemical composition associated with pediatric EoE. Future research to determine the role of these biochemical alterations in development and clinical course of EoE can advance our understanding of EoE pathobiology.
阐明嗜酸性食管炎（EoE）的食管生化组成可以为其发病机制提供新的见解，目前其发病机制尚不清楚。本研究使用拉曼光谱技术对活动期（aEoE）和非活动期（iEoE）EoE 患儿以及非 EoE 对照组患儿的食管样本进行了分析和比较，探讨了光谱标志物与验证的 EoE 活动指数之间的关系。
本研究共纳入 8 例 aEoE 患儿（光谱数=51）、6 例 iEoE 患儿（光谱数=48）和 10 例非 EoE 对照组患儿（光谱数=75），获取了他们的食管样本体外拉曼光谱。采用曼-惠特尼 U 检验比较各组间拉曼强度的差异（中位数[四分位数间距]）并识别光谱标志物。采用斯皮尔曼相关分析评估光谱标志物与内镜和组织学活动指数之间的关系。
与非 EoE 对照组相比，aEoE 患儿的拉曼光谱中糖原含量（936/1,449 cm）峰值（0.20 [0.18-0.21]）较低，而 aEoE 患儿的拉曼光谱中蛋白质（1,660/1,209 cm）峰值（3.20 [3.07-3.50]）较高（P=0.01），iEoE 患儿的拉曼光谱中脂质（1,301/1,260 cm）峰值（1.56 [1.49-1.63]）也较高（P=0.02）。此外，拉曼光谱中糖原和脂质的峰值与嗜酸性粒细胞炎症和基底细胞层增生呈负相关。拉曼图谱进一步证实了我们的发现。
这是第一项鉴定与 EoE 活动和组织病理学相关的食管样本光谱特征以及分析与儿科 EoE 相关的组织水平生化组成的研究。未来的研究确定这些生化改变在 EoE 发展和临床过程中的作用，可以深入了解 EoE 的发病机制。
