Olfactory cleft brushing: A minimally invasive tool for biomarker analysis in rhinology

Olfactory dysfunction is a prevalent condition associated with post-viral syndromes, chronic rhinosinusitis, and neurodegenerative diseases. While olfactory cleft sampling has been investigated in neurology, its potential for assessing localized biomarkers in rhinological conditions remains underexplored. This study presents a minimally invasive nasal brushing technique specifically targeting the olfactory cleft, enabling simultaneous biomarker quantification and cytological analysis. A comprehensive literature review was performed to highlight its potential utility in both clinical practice and research.

Nasal brushing was performed under endoscopic guidance in the olfactory cleft using a cytology brush. Samples were processed to quantify localized biomarkers, including calprotectin, circulating immune complexes, and anti-endothelial cell antibodies, among others. Cytological analysis evaluated cellular composition and inflammatory changes. A literature review focused on nasal brushing applications for biomarker collection across rhinology and other fields.

This technique allowed precise biomarker analysis specific to the olfactory cleft, demonstrating feasibility and reproducibility. The procedure was well-tolerated, with only minor discomfort and occasional spotting reported. Cytological analysis revealed preserved cellular architecture and inflammatory changes in patients with olfactory dysfunction. Reproducibility testing demonstrated consistent biomarker levels (Spearman correlation 0.9) and stable cytological findings.

Olfactory cleft brushing provides a minimally invasive and reproducible approach for assessing localized biomarkers and cytological characteristics in olfactory dysfunction. By focusing on the olfactory cleft, this method offers a targeted tool for advancing the diagnosis and understanding of OD, CRS, and related rhinological conditions.