Immune Clues to Sinus Blues: Linking Biomarkers to Radiologic Score of Rhinosinusitis

Background Chronic rhinosinusitis (CRS) is a prolonged inflammatory condition of the nasal and paranasal sinuses that significantly affects quality of life. This study examines the relationship between CRS severity (based on Lund‐Mackay [LM] scores), osteitis, and systemic inflammatory markers, including neutrophil‐to‐lymphocyte ratio (NLR), platelet‐to‐lymphocyte ratio (PLR), monocyte‐to‐lymphocyte ratio (MLR), basophil‐to‐lymphocyte ratio (BLR), eosinophil‐to‐lymphocyte ratio (ELR), and the systemic immune inflammation index (SII). Methods A retrospective analysis of 208 CRS patients (with or without nasal polyps) who underwent FESS at Jordan University Hospital was performed. Patients were stratified by LM scores into three groups from lowest to highest scores. Inflammatory markers were compared using non‐parametric statistical tests. Results ELR showed the strongest correlation with radiological CRS severity ( p < 0.0001) overall. BLR ( p = 0.0043) and MLR ( p = 0.0199) also showed significant differences, while NLR and PLR did not. ELR was significantly higher in group 3 with the highest Lund–MacKay score for CRS and posterior ethmoid and sphenoid sinus involvement. In patients without nasal polyposis, all markers except MLR showed significant differences with p < 0.05. Conclusions ELR is a promising, non‐invasive biomarker for assessing CRS severity, especially in patients without nasal polyps. It may help evaluate disease burden when imaging is unavailable, offering a cost‐effective tool in clinical practice and a valuable addition to the current management protocol for chronic rhinosinusitis treatment guidelines in low‐ and middle‐income countries.