Elevated mucus interleukin-17A levels are associated with increased prior sinus surgery for chronic rhinosinusitis

Recent advances in molecular biology have enabled the identification of potential inflammatory endotypes of chronic rhinosinusitis (CRS), with prior work suggesting differential short-term surgical outcome trajectories based on cytokine signatures. However, there is a paucity of data assessing long-term treatment failure and need for revision surgery based on inflammatory biomarkers.

Retrospective analysis of prospectively collected cross-sectional data from 231 patients electing surgical therapy for CRS. Intraoperative mucus specimens were quantitatively sampled for inflammatory cytokines using a multiplex flow cytometric bead assay. Univariate Spearman correlations between cytokine levels and prior number of surgeries were assessed. A stepwise adjusted multivariate Poisson regression analysis was used to model patient-reported prior sinus surgery counts as a function of cytokine levels.

Several cytokines (interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, IL-17A, tumor necrosis factor α [TNF-α], interferon γ [IFN-γ], and eotaxin) demonstrated significant positive correlations with number of prior surgeries. However, only higher IL-17A levels were independently associated with a higher number of prior sinus surgeries (β = 0.345, p = 0.0003) after adjusting for the significant covariates of age (β = 0.018, p = 0.0036), Lund-Mackay score (β = -0.046, p = 0.02), history of aspirin-exacerbated respiratory disease (β = 1.01, p < 0.0001) and allergic fungal rhinosinusitis (β = 1.08, p < 0.0001). Higher levels of regulated on activation, normal T-cell expressed and secreted (RANTES) were conversely associated with a lower number of prior surgeries (β = -0.17, p = 0.048).

An IL-17A-predominant cytokine profile is linked to an increased number of prior sinus surgeries. Thus, type 3 inflammatory markers may indicate a particularly difficult-to-treat, recalcitrant CRS endotype.