IGHE and bronchiolitis: ,16 The hyperfunction of Th2 cell subsets and the inhibition of Th1 cell subset functions are the main pathogenic mechanisms of bronchiolitis.17, 18, 19 When Th2 function is in a dominant position, the cytokines and inflammatory mediators secreted by Th2 will also increase, which can promote the differentiation, proliferation, and activation of B cells, produce IgE, and increase serum IgE, while IgE and basophils can participate in allergy, causing a large number of eosinophils to infiltrate locally.