Background: B-cell responses may play a role in the Pathogenesis of nasal polyposis via local IgA and IgE production and activation of eosinophils and mast cells. B-cell attracting chemokines may therefore have relevance in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNPs) Methods: Polyp and inferior turbinate tissues were obtained front CRSwNPs, CRS without NPs (CRSsNPs), and control patients; ELISA and reverse-transcription polymerase chain reaction were used to detect levels of protein and mRNA for selected B-cell chemokines (B-cell attracting chemokine I [CXCL13/B3CA-1/BLC]), thymus expressed chemokine (CCL25/TECK), mucosae-associated epithelial chemokine (CCL28/MEC), stromal cell-derived factor/alpha (CXCL12/SDF-1alpha), and selected chemokine receptor genes (CXCR4, CXCR5, and CXCR7). Results: BCA-1 and SDF-1alpha protein levels were significantly increased in polyp tissue compared with turbinate tissue from CRSsNP patients and controls (p < 0.05 and p < 0.01, respectively). Differences in TECK and MEC were not significant. For mRNA, expression of BCA-1 was significantly up-regulated in polyp tissue and levels correlated with CD20 mRNA expression. Additionally, significant up-regulation of mRNA for the SDF-1alpha receptors CXCR7 and CXCR4 Was detected in polyps, while there was a trend for up-regulation of the BCA-1 receptor CXCR5. Conclusion: Elevated levels of the BCA-1 and SDF-1alpha and their receptors may account for an increased presence of B cells and their products, contributing to eosinophilic inflammation in patients with CRSwNP. (Am J Rhinol Allergy 24, 11-16, 2010; doi: 10.2500/ajra.2010.24.3386)
