Longitudinal stability of chronic rhinosinusitis endotypes

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

“…It is equally possible based on the data presented that IL‐17A is elevated in patients with multiple prior surgeries due to postoperative changes in the mucosa that favor production of these cytokines. A recent study by our group that sampled mucus cytokines in 20 patients before and after ESS did not find statistically significant differences after surgery in levels of IL‐17A, IL‐6, or IL‐8, but did find a significant reduction in RANTES levels 39 . Although the results were limited by sample size, these findings seem to suggest that the associations in the study are less likely to be a response to prior sinus surgery.…”

“…A recent study by our group that sampled mucus cytokines in 20 patients before and after ESS did not find statistically significant differences after surgery in levels of IL-17A, IL-6, or IL-8, but did find a significant reduction in RANTES levels. 39 Although the results were limited by sample size, these findings seem to suggest that the associations in the study are less likely to be a response to prior sinus surgery. Ideally, this study would be conducted in a prospective manner following a longitudinal cohort of patients for years after their primary ESS to assess for the evolution of their disease, but such a study could take a decade or more to perform considering the average reported interval of about 5 years between procedures.…”

International consensus statement on allergy and rhinology: rhinosinusitis 2021

“…In a larger cohort of 90 CRS patients, Turner et al 46 identified 6 disease clusters using a panel of 18 soluble mucus cytokines. This study offered a less invasive method of endotyping than studies using tissue, and the authors proposed that mucus could be used for longitudinal analysis 157 . The majority of CRS patients had elevation of Th2 markers, but only a limited subset had a Th2 dominant profile.…”

Olfactory cleft mucus inflammatory proteins in CRS: a case‐control study

“…There is speculation that this could occur over time via natural history of the disease, that mucus cytokines may not represent underlying endotype, or that cytokines could be altered based on various treatments; however, data exploring this question is quite limited at present. 28 Our study was designed to be crosssectional, and thus, we do not have longitudinal data points to examine stability or reflection of underlying endotype. Thus, caution should be exercised when using individual cytokines obtained at a single point in time to define patient endotypes and subsequent therapies.…”