CRSwNP is classified into eosinophilic and noneosinophilic types based on the level of tissue eosinophilia. The immunopathologic features of Western and Asian CRSwNP differ.

This study aimed to investigate Korean patients’ immunopathologic characteristics with eosinophilic NP versus noneosinophilic NP and those with atopic NP versus nonatopic NP.

Tissue samples were collected from 81 patients with NP and 24 controls. 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-3, Foxp3, RORC, and T-box transcription factor (T-bet), and extracellular matrix, including collagen type I, fibronectin, tissue inhibitor of metalloproteinase 1, and MMP 9.

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 involve any chemical mediators’ expression. GATA-3 mRNA expression increased significantly in patients with eosinophilic NP, and RORC mRNA expression increased significantly in patients with noneosinophilic NP.

The study concluded that 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.