More markers for sinonasal diseases
Reviewed by Badr Eldin Mostafa

In this study, nasal mucus cystatin SN levels were compared in patients with controlled and uncontrolled chronic rhinosinusitis (CRS). Cystatin SN is an epithelium-derived cytokine which regulates cysteine proteases and enhances IL-5 mediated activation of eosinophils. The study included 98 patients with chronic rhinosinusitis and 15 healthy controls. The subjects underwent an extended workup: the 22-item Sino-Nasal Outcome Test (SNOT-22), Questionnaire of Olfactory Disorders-Negative Statements score (QOD-NS), Lund-Kennedy score, Lund-Mackay score, Olfactory Cleft Endoscopy Scale (OCES) and CT scan scores. A multivariate logistic regression analysis was used to determine the risk factors associated with uncontrolled CRS. Cystatin SN expression in the nasal epithelium was significantly increased among patients with uncontrolled CRS compared to those with controlled CRS and healthy controls (both P < 0.001). Furthermore, the uncontrolled CRS exhibited significantly higher scores across all evaluated parameters. Mucus cystatin SN levels showed a positive correlation with blood eosinophil counts and it was found to be an independent predictor of uncontrolled CRS with a cutoff point greater than 106.050 pg/mL.

Association of nasal mucus cystatin SN levels with disease severity in patients with uncontrolled chronic rhinosinusitis. 
Pan X, Li Y, Liu Z, et al.
EUR ANN OTORHINOLARYNGOL HEAD NECK DIS
2026;143(3):167–74.