Nasal biomarker profiles in acute and chronic rhinosinusitis

Background Clinical manifestations of rhinosinusitis include acute rhinosinusitis, chronic rhinosinusitis (CRS) with nasal polyps and CRS without polyps. Objective Possible mechanisms defining these three forms of rhinosinusitis should be investigated assessing biomarker profiles in nasal secretions. Methods Fifteen cytokines, three cellular activation markers and total IgE were determined in nasal secretions of seven patients with acute rhinosinusitis, 12 patients with CRS without polyps, 13 patients with CRS with polyps and six healthy controls. Principal component analysis was used to extract relevant factors. Results Irrespective of the clinical manifestation, all biomarkers assessed were increased in patients with rhinosinusitis when compared with controls (P < 0.001). Principal component analysis allowed the extraction of three factors explaining 83% of data variance. The general inflammatory activation was mainly reflected by the first factor. The second factor differentiated acute from CRS. This factor correlated with IL-12, which is involved in pathogen-related immune activation by antigen-presenting cells. It was also positively correlated with IL-4, IL-10 and IL-13, which play an important role in the resolution of infections. The third factor differentiated CRS with polyps from CRS without polyps (P=0.001). It represented IL-5 and nasal IgE (nIgE), whereas eosinophil cationic protein and tryptase were not specific for CRS with polyps. Conclusion In mucosal infection, numerous inflammatory mediators are activated. Simple correlations of few biomarkers with a specific disease process bear the risk of overestimating a possibly unspecific effect. To assess biomarker profiles, more complex analytic tools may be more appropriate to delineate mechanisms underlying mucosal disease. Using principal component analysis, it was found that high nIgE and IL-5 levels are specific for CRS with nasal polyps.