Immunopathologic characteristics of nasal polyps in adult Koreans: A single-center study.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (NP) (CRSwNP) is classified into eosinophilic and noneosinophilic types based on the level of tissue eosinophilia. The immunopathologic features of Western and Asian CRSwNP differ.

OBJECTIVES: The aim of this study was to investigate the immunopathologic characteristics of Korean patients with eosinophilic NP versus noneosinophilic NP and those with atopic NP versus nonatopic NP.

METHODS: Tissue samples were collected from 81 patients with NP and 24 controls. The clinical characteristics of all the patients were analyzed. Tissues were investigated for expression of chemical mediators, including interleukin (IL) 5, IL-10, IL-17, interferon-γ, and tumor growth factor-β1; transcription factors, including GATA binding protein 3 (GATA-3), forkhead box P3 (Foxp3), retinoic acid-related orphan receptor C (RORC), and T-box transcription factor (T-bet), and extracellular matrix, including collagen type I, fibronectin, tissue inhibitor of metalloproteinase 1, and matrix metalloproteinase (MMP) 9.

RESULTS: Although the clinical characteristics differed between eosinophilic and noneosinophilic NPs, atopic status did not affect the clinical findings of CRSwNP. Both T-helper 1 and 2 cytokines increased significantly in patients with eosinophilic NP, but atopic status did not affect the expression of any of the chemical mediators. GATA-3 messenger RNA (mRNA) expression increased significantly in patients with eosinophilic NP, and RORC mRNA expression increased significantly in patients with noneosinophilic NP. T-bet, RORC, and Foxp3 mRNA expression increased significantly in patients with nonatopic NP. Fibronectin and MMP-9 mRNA expression increased significantly in patients with noneosinophilic NP, whereas only MMP-9 mRNA increased significantly in patients with eosinophilic and those with noneosinophilic NP.

CONCLUSION: The immunopathologic characteristics differed between eosinophilic NP and noneosinophilic NP and between atopic NP and nonatopic NP. The different underlying pathogenic processes may influence the development of Korean NP.