ABSTRACT
OBJECTIVES: The pathophysiological mechanisms of chronic rhinosinusitis with nasal polyposis (CRSwNP) still are discussed controversially. Regulatory B cells (Breg) are responsible for the suppression of T cell activity: deficiencies for Breg have been demonstrated to contribute to autoimmune disorders, e.g., systemic lupus erythematosus. In order to evaluate the influence of B cell subpopulations, especially Breg, on the etiology of this disease, the aim of this study was to characterize subpopulations of peripheral and edaphic B cells in CRSwNP. METHODS: Polypoid tissue and blood samples were collected from 10 patients undergoing paranasal sinus surgery and lymphocytes were analyzed by multicolor flow cytometry. RESULTS: There was a significantly lower frequency of B cells in nasal polyps compared to peripheral blood mononuclear cells (PBMC) in patients with CRSwNP. Mature resting B cells were the main population within B cells in PBMC, and memory B cells in nasal polyps. Remarkably, Breg and mature B cells significantly decreased in nasal polyps compared to PBMC. Memory B cells significantly increased and represented the main subpopulation in nasal polyps in patients with CRSwNP. CONCLUSION: In this study a detailed contemporary characterization of B cell subpopulations in patients with CRSwNP is presented. The influence of edaphic B cells could play a key role in the maintenance of this chronic infectious disease.