Topical and systemic steroids constitute the first choice in medical treatment for nasal polyps. Glucocorticoids sensitivity is significantly correlated with CST1 level in nasal secretions. The goal of this single-arm clinical trial based on a multicenter platform is to test CST1 in patients with chronic rhinosinusitis and nasal polyps before and after oral glucocorticoid therapy. Endoscopic polyp score, Total Nasal Symptom Score(TNSS), SNOT-22 score and other biomarkers are also evaluated before and after the treatment. Researchers will develop a CST1 predictive model of oral glucocorticoid therapy for Chronic Rhinosinusitis with Polyps.

Inclusion Criteria:

1. All meet the diagnostic criteria of CRSwNP in EPOS2020 (Age 18-70 years old);
2. Investigator-assessed endoscopic bilateral Nasal Polyp Size Score (NPSS) was greater than or equal to 4 (minimum score of 2 per nasal cavity);

Exclusion Criteria:

1. Oral glucocorticoid contraindications, such as diabetes, femoral head necrosis, gastric ulcer, etc.
2. Medication history of oral glucocorticoids or immunomodulator within 1 months before enrollment, antibiotics within 2 weeks;
3. fungal sinusitis, allergic fungal sinusitis (AFRS), cystic fibrosis, primary ciliary dyskinesia