Correlation between inflammatory biomarkers and disease control in chronic rhinosinusitis with nasal polyps

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) may have a heterogeneous response to medical/surgical treatments based on endotypes. Data correlating biomarkers and severity of the disease are lacking. We aimed to determine if IL-5 and calprotectin may be useful in defining severity of disease and identifying uncontrolled patients. Methods: This was a case–control study including 81 patients with diffuse CRSwNP who underwent at least one previous surgery and treated with intranasal steroids. We enrolled 39 uncontrolled patients (SNOT-22 ≥ 40 and two or more cycles of systemic corticosteroids in last year) (Group A) and 42 controlled one (SNOT-22 < 40 and less than two cycles of systemic corticosteroids in last year) (Group B). We analyzed IL-5 and calprotectin in both nasal secretions and nasal polyp tissue. Results: Calprotectin and IL-5 were significantly higher in Group A in both secretions and tissue, and the higher the number of previous surgeries, the higher the levels detected in nasal secretions. At univariate analyses, smoking, asthma, non-steroidal anti-inflammatory drugs-exacerbated respiratory disease (NSAID-ERD), blood eosinophilia, neutrophils, and eosinophils at nasal cytology were significantly associated with uncontrolled disease. Multivariate analyses showed that asthma, NSAID-ERD, and IL-5 in nasal secretion/polyp tissue were significantly related to the risk of uncontrolled disease. Conclusions: Our data suggest that asthma, NSAID-ERD, and IL-5 in nasal secretions/tissue may be helpful to identify more severe patients, as they are related to the risk of uncontrolled disease. Nonetheless, high levels of calprotectin and neutrophilia were also observed in uncontrolled patients, especially after multiple surgeries.