Role of microRNA in chronic rhinosinusitis

The pathogenesis of chronic rhinosinusitis (CRS) shows strong connections with microRNA-155 (miR-155) through its inflammatory pathways. Research has concentrated on determining miR-155 expression levels in patients who receive montelukast treatment as a leukotriene receptor antagonist for asthma and allergic conditions. The immune system depends on miR-155 for its regulation through its effects on T cells and macrophages. The elevated levels of miR-155 promote Th2-mediated inflammation through increased eosinophilic activity and elevated IL-4 and IL-13 pro-inflammatory cytokines. Research on patients with asthma and allergies who take montelukast shows that the medication may adjust miR-155 expression levels, thus enabling the immune system to achieve better balance through microRNA downregulation. This study examined 30 patients diagnosed with CRS who did not respond to medical treatment and therefore underwent surgery. Blood samples were taken from the patients before the operation to measure IL-1β and miR-155 levels. They were asked to answer the Sino-Nasal Outcome Test (SNOT-22) to evaluate sinonasal symptoms. After the operation, these patients were given a standard treatment and nasal irrigation with montelukast and saline for one month. One month later, IL-1β and miR-155 levels were measured in serum samples taken from the patients. The SNOT-22 questionnaire was repeated. When the SNOT-22, miRNA155 and IL-1β values obtained after the operation were compared with the values before the operation, it was seen that they decreased and this difference was found to be statistically significant (p=0.0001, p=0.0030, p=0.0001; respectively). The disease severity and inflammatory status of patients could be monitored through elevated serum miR-155 levels. The significance of miR-155 in chronic rhinosinusitis makes it both a therapeutic target and a biomarker for disease management.