Cytokine Sampling in the Nasal Cavity and Paranasal Sinuses

Background: Cytokines are crucial mediators in cell-to-cell communication, immune regulation, and the pathophysiology of rhinologic diseases. Distinguishing cytokine profiles can elucidate inflammation types [eg, T-helper type 1 (Th1), Th2, and Th17] and guide therapeutic options. Various methods for cytokine sampling in the sinonasal cavity exist. This review aimed to provide an in-depth review of these methods, including their advantages, limitations, and analytical techniques. Methods: A narrative literature review was conducted using Medical Subject Headings (MeSH) keywords in PubMed and Google Scholar. Key MeSH terms include “cytokines,” “mucus,” “interleukins,” “biomarkers,” “sinonasal disease,” “chemokines,” “paranasal sinuses,” and “sampling.” Results: There are many different methods of cytokine sampling in the sinonasal cavity. Common methods include nasal lavage, forced exhalation, collection of nasal epithelial lining fluid, nasopharyngeal swab, cytobrush, sponge, suction, and tissue biopsy. Each method used has advantages and limitations, such as type of sample collected, location specificity, invasiveness, sample dilution and volume variability, and utility for downstream analytical assays. Conclusions: Advancements in cytokine sampling and pharmacological targeting in sinonasal disease are instrumental for the diagnosis and management of patients with sinonasal disease. Understanding these methods’ strengths and weaknesses can improve patient care and guide treatment development.