The use of immunologic and histopathologic characteristics to classify chronic rhinosinusitis subtypes

Chronic rhinosinusitis (CRS) is a broad clinical syndrome traditionally distinguished primarily by the endoscopic findings of the presence or absence of nasal polyps. Increasing evidence, however, suggests that CRS may be further differentiated by their distinct underlying pathophysiologic mechanisms. Purpose of the study was to review recent insights into the mechanisms of CRS pathogenesis and to assess the potential for a classification of CRS into subtypes. Classification schemes have utilized the immunologic and histopathologic profiles of CRS to characterize the phenotypic and potentially endotypic heterogeneity of this disorder. The CRSsNP phenotype has been linked to a less Th2 and relatively more Th1/Th17 polarization and greater collagen deposition. The CRSwNP phenotype has been associated with a Th2 skewing, elevated IgE levels, tissue edema, and a closer linkage to asthma. The immunohistologic characterization of CRS subtypes reflects the diverse pathophysiologic mechanisms associated with this syndrome. Identification of specific biomarkers associated with these variants may ultimately refine the diagnostic criteria of CRS, permitting the targeting of specific pathways contributing to the symptomatology expressed in individual patients.