The role of ADAM-like decysin 1 in non-eosinophilic chronic rhinosinusitis with nasal polyps

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is classified into two subtypes: eosinophilic (ECRSwNP) and non-eosinophilic (NECRSwNP). Although the inflammatory patterns of ECRSwNP have been elucidated, NECRSwNP is poorly understood. Aims/objectives: The metalloproteinase ADAM-like decysin 1 (ADAMDEC1) has been reported to play a role in the early stages of the inflammatory response. We investigated the role of ADAMDEC1 in the pathogenesis of CRSwNP. Material and methods: We compared ADAMDEC1 expression in nasal polyp tissue from CRS patients using immunohistochemistry and RT-qPCR. Macrophages were cultured and ADAMDEC1 expression was determined at baseline and after exposure to lipopolysaccharide (LPS). Results: ADAMDEC1 was virtually undetectable in tissues from control patients but was highly expressed in the NECRSwNP group compared with the ECRSwNP group. In nasal polyp tissues, ADAMDEC1 was expressed by CD68-positive cells, with a positive correlation between ADAMDEC1-positive and CD68-positive cells, and also between ADAMDEC1 and CD68 mRNA levels. Furthermore, stimulation of monocyte-derived macrophages with LPS induced ADAMDEC1 expression. Conclusions and significance: This study demonstrates that ADAMDEC1 is involved in the pathogenesis of NECRSwNP, and also bacterial endotoxin signalling in macrophages; however, the underlying mechanism remains to be elucidated.