MBP and congenital rubella syndrome: No significant difference in HRV detection in CRS vs. controls during acute exacerbations.Increased levels of IL-6 in CRSwNP patients at baseline was seen.A local immune response with elevated IL-5, IL-6 and eosinophil major basic protein (MBP) in nasal secretions between CRSwNP and controls during acute exacerbation.