The aim of this study was, firstly, to classify patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic rhinosinusitis without nasal polyps (CRSsNP) into inflammatory endotypes and, secondly, to investigate the relationships between blood and tissue eosinophilia and clinical outcomes in CRSwNP, including disease severity, and recurrence. This cross-sectional, observational, nonrandomized study has been realized between January 2023-December 2024 enrolling a sample of 469 consecutive patients with chronic rhinosinusitis, of which 239 patients with CRSwNP and 230 patients with CRSsNP. The classification of CRSwNP and CRSsNP into inflammatory endotypes was performed by analyzing the levels of blood and tissue eosinophilia. The prevalence of asthma and allergy to nonsteroidal anti-inflammatory drugs (NSAIDs) in the two groups was also analyzed. In the group of patients with CRSwNP, the severity of the disease and the level of quality of life impairment were evaluated, depending on the degree of tissue eosinophilia. The importance of the association between blood vs. tissue eosinophilia and the relapse of CRSwNP was also assessed. The proportion of patients with elevated blood eosinophil levels was higher in CRSwNP than CRSsNP (17.4% vs. 4.35%). Tissue eosinophilia was identified in 163 of 235 (69.4%) patients with CRSwNP compared with 29 of 230 (12.6%) patients with CRSsNP. From an inflammatory perspective, revision surgery was strongly associated with tissue eosinophilia. In contrast, elevated blood eosinophil levels were only moderately associated with revision surgery.
Milea et al. (Sat,) studied this question.