[The role of type 2 innate lymphoid cells in the pathogenesis of eosinophilic chronic rhinosinusitis with nasal polyps].

Objective

To investigate the type 2 innate lymphoid cells (ILC2s) in eosinophilic nasal polyps, non-eosinophilic nasal polyps and controls, and to compare the characteristics of ILC2s indifferent types of nasal polyp.

Methods

Flow cytometric analysis was used to quantify the ILC2s and Th2 cells in tissues from 19 patients with chronic rhinosinusitis with nasal polyp (CRSwNP) and 6 controls. The patients were classified into two groups as eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) and non-eosinophilic chronic rhinosinusitis with nasal polyps (non-ECRSwNP) based on eosinophil counts under hematoxylin-eosin staining. ILC2 and Th2 cell frenquencies, measured as a percentage of CD45(+) cells, were compared among ECRSwNP group (n=9), non-ECRSwNP group (n=10) and control group (n=6) using Mann-Whitney U test .The correlation between ILC2, Th2 cell frequencies and eosinophil count in tissues was analyzed using Pearson correlation coefficient.

Results

ILC2 frequencies in ECRSwNP group were significantly higher than non-ECRSwNP group and controls ((0.051±0.025) vs (0.011±0.017), (0.051±0.025) vs (0.004±0.004), Z value was -3.185, -3.186, respectively, both P<0.05). There was no significant difference between ILC2 frequencies in non-ECRSwNP and controls ((0.011±0.017) vs (0.004±0.004), Z=-0.712, P=0.492). Th2 cell frequencies in ECRSwNP and non-ECRSwNP group were significantly higher than controls ((0.500±0.437) vs (0.106±0.102), (0.275±0.170) vs (0.106±0.102), Z value was -2.946, -2.278, respectively, both P<0.05). There was no significant difference between Th2 frequencies in non-ECRSwNP group and ECRSwNP group ((0.275±0.170) vs (0.500±0.437), Z=-1.306, P=0.211). ILC2 frequencies significantly correlated with Th2 cell frequencies (r=0.571, P=0.011) and tissue eosinophilia (r=0.579, P=0.009). Th2 cell frequencies significantly correlated with tissue eosinophilia (r=0.844, P=0.001). There was no significant association between ILC2 and allergic status.

Conclusion

ILC2s are elevated in ECRSwNP, and not influenced by allergic status, suggesting that ILC2s play an important role in ECRSwNP without allergic diseases.