Expression of inflammatory and B cell markers in the NP group. Total RNA was extracted from nasal tissues, and expression of CD19 (B cell marker [A]), CD138 (plasma cell marker [B]), CD11c (dendritic cell marker [C]), and mast cell protease-6 (MCP6) (mast cell marker [D]) was analyzed using real-time PCR. In more analyses of B cell activation, mRNA expression of B cell–activating factor (BAFF) (E) and a proliferation-inducing ligand (APRIL) (F) was found to be significantly increased in mouse NP tissue. BAFF protein concentration in nasal lavage fluid (NLF) was also significantly higher in the NP group than in the control (G). Data presented are means ± SEM. *P < 0.05 versus control.