Unveiling the prevalence and impact of silent rhinovirus infection in chronic rhinosinusitis with nasal polyps.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNPs) involves persistent sinus inflammation, with emerging evidence suggesting a potential role of rhinovirus (RV) in its pathophysiology. However, whether RV exists in nasal tissues and affects the nasal mucosa after the resolution of infection symptoms remains unknown.

Objective: To investigate the prevalence and impact of silent RV infection in nasal tissues.

Methods: RV loads were detected in the nasal tissues of 47 controls and 101 patients with CRSwNP without respiratory infection. Participants were categorized into RV-positive (+), RV-negative (-), and the "gray zone" groups. Quantitative polymerase chain reaction, Western blotting, and immunofluorescence assays were used to analyze the impact of silent RV infection on the immune status of nasal tissues.

Results: Silent RV infection was prevalent in both control (34%) and CRSwNP (30.7%) tissues, with higher viral loads observed in the nasal polyps. In controls, it was associated with high expression of types 1 and 2 interferon (IFN), type 2 inflammation, interleukin (IL)-17A, and IL-10. In patients with CRSwNP, silent RV infection was associated with lower levels of type 1 IFN, IL-17A, type 2 inflammation, and IL-10 but higher levels of type 2 IFN compared with those without RV infection. Meanwhile, RV (+) nasal polyps exhibited fewer tissue eosinophils and neutrophils than RV (-) nasal polyps.

Conclusion: Silent RV infection was prevalent in the nasal tissues, with a higher viral load detected in the nasal polyps. This silent RV infection is associated with distinct immune responses in healthy controls and patients with CRSwNP, involving differential modulation of IFNs, T2 cytokines, IL-17A, IL-10, and eosinophil and neutrophil levels.