Characterization of B-cell subpopulations in patients with chronic rhinosinusitis.

BACKGROUND: Recent research suggest that B and plasma cells may play an important role in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). The purpose of this study was to subcharacterize the B cell response in the sinus mucosa of control and CRS patients. METHODS: Representative tissue samples and peripheral blood samples were obtained from controls, CRS without nasal polyps (CRSsNP) and CRSwNP. Using single-cell suspension flow cytometry these samples were analyzed for overall and stage-specific B and plasma cell percentages. RESULTS: Both atopic and nonatopic CRSwNP patients showed an increase in local numbers of naive, active, and memory B cells compared to controls. CRSsNP patients only showed local elevations of naive B cells. Plasma cells were only significantly elevated in the sinus tissue of atopic CRSwNP patients. These local tissue increases did not correlate with increased numbers of circulating B cells. CONCLUSION: This study provides further evidence of an important role of B cells in CRSwNP patients. The local increase appears to be independent of a systemic response.