Correlations of pre- and post-operative symptoms with cytokines in different phenotypes and endotypes of chronic rhinosinusitis.

Background: Recognising inflammatory endotypes in chronic rhinosinusitis (CRS) has become more important, especially with the advent of biological treatments. In this study, we investigated the correlations of pre- and post-operative symptoms with cytokine positivity in different endotypes and phenotypes of CRS.

Methodology: In total, 102 patients undergoing routine functional endoscopic sinus surgery were enrolled. The endotype classification (type 1, 2, or 3 CRS) was defined based on positivity for interferon-Α, interleukin (IL)-5, or IL-17 respectively, in sinonasal tissue samples. Clinical symptom scores were evaluated pre- and post-operatively using the 22-item Sinonasal Outcome Test and its four symptom subdomains: sleep, nasal, otologic/facial symptoms, and emotional function. Symptoms were compared between endotypes and phenotypes, and exploratory factor analysis (EFA) based on principal component analysis (PCA) was performed. The correlations of cytokine levels with baseline symptoms and changes in symptoms after 1 year were analysed.

Results: Symptoms in the otologic/facial pain category were associated with non-type 2 endotypes in PCA and confirmatory analysis. Non-type 2 CRS patients exhibited significantly more improvement in facial symptoms 1 year after surgery. Neutrophil-associated cytokines, such as IL-17, matrix metalloproteinase 9, and myeloperoxidase, were significantly correlated with baseline otologic/facial pain symptoms and changes in those symptoms after surgery.

Conclusions: Otologic/facial pain symptoms may be indicative of non-type 2 endotypes. Neutrophil-associated cytokines, such as IL-17, MMP-9, and MPO, were significantly correlated with these symptoms. The establishment of links between specific symptoms and certain cytokines may help use and develop biological therapies for CRS.