The association between serum MST1 and the prognosis in patients with chronic rhinosinusitis with nasal polyps after functional endoscopic sinus surgery.

Background and Aims: Chronic rhinosinusitis with nasal polyps (CRSwNP) is prone to postoperative recurrence. This study aimed to investigate the association between serum mammalian Ste20-like kinase 1 (MST1) and prognosis in CRSwNP patients after functional endoscopic sinus surgery (FESS). Methods: This prospective observational study included 100 CRSwNP patients undergoing FESS and 100 patients with nasal septal deviation or maxillary sinus cysts as controls. Serum levels of MST1, IFN-γ, and IL-5 were measured using Enzyme-linked immunosorbent assay (ELISA). MST1 mRNA expression in nasal polyps and inferior turbinate samples was quantified by qRT-PCR. Sinus lesions and quality of life were assessed using the Lund-Mackay, Lund-Kennedy, and SNOT-22 scoring systems. The 1-year recurrence-free survival was analyzed using Kaplan-Meier (K-M) curve, and the diagnostic value of MST1 for CRSwNP was evaluated by Receiver operating characteristic (ROC) curve. Results: Serum MST1 levels and MST1 mRNA expression were significantly elevated in CRSwNP patients. High MST1 expression positively correlated with increased eosinophils percentage and elevated IL-5 levels. Moreover, patients with lower MST1 expression exhibited better clinical outcomes and a lower recurrence rate. Logistic regression analysis identified MST1 and allergic rhinitis as independent predictors of recurrence. Furthermore, MST1 demonstrated a strong predictive value for recurrence in CRSwNP patients. Conclusion: Elevated serum MST1 levels were strongly associated with inflammation, disease severity, and recurrence risk in CRSwNP. These findings suggest that MST1 could serve as a valuable prognostic biomarker for postoperative outcomes in CRSwNP patients.