Increased expression of type 2 innate lymphoid cells in pediatric patients with allergic rhinitis

Abstract

Type 2 innate lymphoid cells (ILC2s) are a newly identified group of innate immune cells. ILC2s promote features of allergic airway diseases through the secretion of Th2 type cytokines, including interleukin (IL)-4, IL-5 and IL-13. It remains unknown whether ILC2s aggregate in the peripheral blood. The present study examined the ILC2 levels in pediatric patients with allergic rhinitis (AR), and the correlation with the severity of clinical symptoms. Flow cytometry detected the ILC2s frequency in the peripheral blood of 12 healthy controls (HCs), 12 patients with AR sensitized only to house dust mites (HDM-AR), and 18 AR patients monosensitized to other antigens including weeds, animal danders and Blattella germanica, but not including HDM (non-HDM-AR). Clinical symptoms of AR were expressed according to the Total 5 Symptom Score (T5SS). The percentages of ILC2s in the peripheral blood were increased significantly in patients with HDM-AR and non-HDM-AR, compared with that in the HCs. A subgroup analysis of patients with AR indicated that the proportion of ILC2s was significantly increased in HDM-AR in comparison with that in non-HDM AR. Furthermore, there was a notable correlation between ILC2 levels and T5SS scores. ILC2s frequencies in PBMC were increased significantly in pediatric patients with AR, irrespective of the type of allergen. HDM may trigger more severe allergic reactions and an increase in the number of ILC2s. These discoveries indicate the unique function of ILC2 in AR and provide a potential therapeutic target.

Research Advances in the Treatment of Allergic Rhinitis by Probiotics

“… 107 Children with HDM-AR had significantly higher levels of ILC2 in peripheral blood than children without HDM-AR. 108 All these findings suggest that ILC2s play an important role in regulation in AR. Meanwhile, in a study of papain-induced BL6 mice, treatment with the probiotic Escherichia coli strain Nissle 1917 (ECN) resulted in a smaller decrease in IL-5, a significant decrease in IL-13, and a significant decrease in IL-33 levels.…”

The Role of Type 2 Innate Lymphoid Cells in Allergic Diseases

“…It is worth noting that the number of ILC2s in patients with HDM-induced AR was significantly higher than that in those with mugwort-AR ( 116 ). The peripheral blood ILC2 content was considerably higher in human pediatric patients with HDM-AR than in those without HDM-AR ( 117 ). The possible mechanism underlying this difference is that HDM is more immunogenic than plant-derived allergens, and its sensitization mechanism is presumably different from that of plant-based allergens, such as wormwood pollen ( 118 ).…”

Zonula occludens and nasal epithelial barrier integrity in allergic rhinitis

“…Cytokines play an important role in mediating allergic inflammation. The roles of Th2 cytokines in AR have been well-documented (Steelant et al, 2016;Sun et al, 2020;Zhao et al, 2017). Imbalance of Th1 and Th2 cytokines appears to be involved in the AR inflammatory pathway (Zhao et al, 2017).…”