CRS is a process involving a number of adverse changes in the mucosa of the paranasal sinuses and nasal polyps, e.g. increased fibroblast proliferation, angiogenesis, increased formation of fibrous tissue (subepithelial fibrosis) and tissue destruction. There are biomarkers whose levels can be increased in chronic inflammation of the paranasal sinuses: peripheral blood eosinophilia, IgE immunoglobulin, cytokines - IL-4, IL-5, IL-13, IL-25, IL-33, periostin, P-glycoprotein, CXCL-12, CXCL-13, INF-Upsilon, TNF alpha, TGF beta 1, albumins, eotaxin. These biomarkers are not pathognomonic for CRS. The concentration of biomarkers is also increased in bronchial asthma and atopic dermatitis. The TGF beta, in particular the beta 1 subunit, was identified as the main factor involved in the remodelling of tissue stroma. In conjunction with continuous improvement of tissue testing methods, it is advisable to search for new factors that will more accurately allow the assessment of tissue remodelling in the chronic processes of paranasal sinuses.

Chronic rhinosinusitis is a process involving a number of adverse changes in the mucosa of the paranasal sinuses and nasal polyps. The main histological features of tissue remodeling are changes in epithelial structure, oedema, degradation of ECM (extracellular matrix), angiogenesis, and subepithelial fibrosis. In this study, patients were divided into two groups: group 1—patients with CRSwNP (chronic rhinosinusitis with nasal polyps) taking a nasal steroid and an oral steroid in the preoperative period, and group 2—patients with CRSwNP taking only the nasal steroid in the preoperative period. All samples were subject to histopatologic evaluation. The aim of this study was to investigate the effect of oral corticosteroids and topical steroids on the tissue of paranasal sinuses. We have shown statistically significant decreases in tissue eosinophilia per 5HPF and decreased fibrosis in group 1. No significant differences were presented in the percentage of total tissue oedema, epithelium, neutrophils, basement membrane thickening and vessels. Using systemic administration of 40 mg of prednisone for seven days decreased the counts of eosinophils and decreased fibrosis in the nasal polyps tissue in CRSwNP.

There have been a few reports confirming that vitamin D (VD3) deficiency increases inflammation in the paranasal sinuses. The work brings new information that, despite the presence of inflammation before surgery, patients with higher vitamin D levels had less inflammation, and this has been proven on three levels. We show that vitamin D levels clearly correlate with the severity of the disease in chronic sinusitis. These results have been confirmed in imaging studies (Lund MacKay scale), endoscopy (Lund-Kennedy scale) and in the SNOT 20 questionnaire. 40 patients suffering from chronic sinusitis were divided into two equal groups: group 1: with less severe radiological changes (10 or less points on the Lund-Mackay scale), group 2: with a more advanced form (>10 points). The relationship between VD3 and the severity of the disease (clinical and nasal endoscopy) was assessed. The mean VD3 level in patients in group 2 before surgery was lower (23.01 ng/mL) than in group 1 (28.02 ng/mL) (p < 0.05). They presented a higher degree of advanced changes in all the above scales, i.e., before the SNOT 20 procedure, the mean was: group 1: 30.33, group 2: 31.80 (p < NS); Lund-Kennedy: group 1: 3.21, group 2: 6.30 (p < 0.05). After surgery an increase in VD3 levels was observed in both study groups: in group 1 to the value of 37.98 ng/mL (p < 0.002) and in group 2 to 27.67 ng/mL (p < 0.004). Lower VD3 levels were found in patients with a higher stage of the disease. Reduction of inflammation increases the level of VD3 and reduces subjective and objective symptoms of chronic inflammation.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial inflammatory disease characterized by heterogeneous phenotypes and endotypes, necessitating personalized therapeutic strategies. Precision medicine approaches integrating molecular biomarkers may improve treatment selection and disease stratification. In this prospective controlled study, we investigated the tissue-level immunohistochemical effects of oral corticosteroids (OCSs) and topical steroids on the expression of periostin, eotaxin, interleukin-4 (IL-4), transforming growth factor-β (TGF-β), and tumor necrosis factor-α (TNF-α) in nasal polyp tissue. Sixty-five patients eligible for endoscopic sinus surgery (ESS) were enrolled and divided into two groups: Group 1 (n = 42) received topical steroids combined with oral prednisone (40 mg/day for 7 days preoperatively), whereas Group 2 (n = 23) received topical steroids alone. Immunohistochemical analysis demonstrated a significant reduction in periostin and eotaxin expression in both epithelial and stromal compartments following OCS therapy, accompanied by increased TGF-β expression. No significant differences were observed in IL-4 or TNF-α expression. These findings indicate that short-term OCSs selectively modulate molecular pathways associated with eosinophilic inflammation and tissue remodeling in CRSwNP, supporting biomarker-driven precision medicine strategies.