Background: Asthmatic nasal polyps primarily exhibit eosinophilic infiltration. However, the identities of the immune cells that infiltrate non-asthmatic nasal polyps remain unclear. Thus, we thought to investigate the distribution of innate immune cells and its clinical relevance in non-asthmatic chronic rhinosinusitis (CRS) in Korea.
Methods: Tissues from uncinate process (UP) were obtained from controls (n = 18) and CRS without nasal polyps (CRSsNP, n = 45). Nasal polyps (NP) and UP were obtained from CRS with nasal polyps (CRSwNP, n = 56). The innate immune cells was evaluated by immunohistochemistry such as, eosinophil major basic protein (MBP), tryptase, CD68, CD163, CD11c, 2D7, human neutrophil elastase (HNE) and its distribution was analyzed according to clinical parameters.
Results: In comparisons between UP from each group, CRSwNP had a higher number of MPB(+), CD68(+), and CD11c(+) cells relative to CRSsNP. Comparisons between UP and NP from CRSwNP indicated that NP have a higher infiltrate of MBP(+), CD163(+), CD11c(+), 2D7(+) and HNE(+) cells, whereas fewer CD68(+) cells were found in NP. In addition, MBP(+) and CD11c(+) cells were increased from UP of CRSsNP, to UP of CRSwNP, and to NP of CRSwNP. Moreover, in UP from CRSwNP, the number of MBP(+) and CD11c(+) cells positively correlated with CT scores. In the analysis of CRSwNP phenotype, allergic eosinophilic polyps had a higher number of MBP(+), tryptase(+), CD11c(+), 2D7(+) cells than others, whereas allergic non-eosinophilic polyps showed mainly infiltration of HNE(+) and 2D7(+) cells.
Conclusions: The infiltration of MBP(+) and CD11c(+) innate immune cells show a significant association with phenotype and disease extent of CRS and allergic status also may influences cellular phenotype in non-asthmatic CRSwNP in Korea.