Lipidomics Profiling of Skin Surface Lipids in Senile Pruritus

Abstract Background: Senile pruritus is common, yet its etiology remains unknown. We examined the lipidomics profiles of skin surface lipids (SSL) in the elderly to better understand potential causes for senile pruritus. Methods:Transepidermal water loss (TEWL) was used to assess skin barrier function. Ameliorated Kawashima itch scale were used to measure the pruritus score. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and multivariate data analysis were used to investigate SSL alternations. Results:The results showed that the senile pruritus have higher TEWL values than controls (13.13±4.28 versus 6.71±2.45, p< 0.01). LC-MS/MS showed significant differences in lipidomics and identified 81 species of SSL that differ between two groups. Compared to controls, the levels of ceramides, diacylcerols, fatty acids, phosphatidylcholines, phosphatidylethar, phytosphingsines, sphingosines, diacylceryl-3-O-carboxyhydroxymethylcholine, diacylglyceryl trimethylhomoserine, unsaturated free fatty acids increased, whereas triacylglycerol decreased. CER-EOS, CER-NDS and CER-NS were positively correlated with TEWL values (p<0.05). Sphingomyelin, Cer-NP, Cer-AS, Cer-NDS, Cer-NS were positively correlated with pruritus severity scores, while Cer-BS, Cer-EODS, Cer-EOS, Cer-AP were negatively correlated. Conclusion:Our study indicated that the senile pruritus have impaired skin barrier function and altered SSL composition. Select SSL species identified in this study may be potential target for future studies on the pathogenesis of idiopathic senile pruritus