FTIR Microspectroscopy for the Analysis of Inflammatory and Immune Responses in Nasal Polyps Treated With Local Glucocorticoids

Introduction Rhinosinusitis is a significant health issue that parallels the increasing prevalence of allergic rhinitis. We aimed to investigate the biochemical, inflammatory, and immunological components involved in the topical glucocorticoid (GC) response in chronic rhinosinusitis with nasal polyps (CRSwNP) using Fourier transform infrared microspectroscopy (FTIRM). Methods We analyzed nasal mucosa (NM) from healthy individuals ( n = 10) and patients diagnosed with CRSwNP ( n = 20) using FTIRM. For this purpose, cryosections of the NM biopsies were obtained, and the epithelium and connective tissues were analyzed separately, thereby identifying the main biomolecules and components associated with inflammatory and immune responses. Results The most common reported signs and symptoms were nasal obstruction, rhinorrhea, and frontal headache, with allergic rhinitis as the main comorbidity. FTIRM spectra showed no statistically significant differences in structural or biochemical composition between CRSwNP and healthy groups in either the epithelium or connective tissue sections. Notably, absorbance bands related to phosphodiester bonds, phosphorylated molecules, and IL‐6, IL‐10, and IFN‐γ were elevated in the epithelium region of the CRSwNP group, indicating enhanced inflammatory and immune responses. In contrast, in the connective tissue region, most inflammatory components, except IL‐6 and IFN‐γ, exhibited lower absorbance in the CRSwNP group, highlighting regional differences in biomolecular response. Conclusion TNF‐α and IgA were identified as the principal biomarkers most affected by GC treatment in the CRSwNP group, underscoring their potential as indicators of treatment response.