Impact of high‐altitude therapy on type‐2 immune responses in asthma patients

Abstract

Background: Asthma patients present with distinct immunological profiles, with a predominance of type 2 endotype. The aim of this study was to investigate the impact of high-altitude treatment on the clinical and immunological response in asthma. Methods: Twenty-six hospitalized asthma patients (nine eosinophilic allergic; EA, nine noneosinophilic allergic; NEA and eight noneosinophilic nonallergic; NN) and nine healthy controls in high altitude for 21 days were enrolled in the study. We assessed eosinophils, T cells, Tregs, and innate lymphoid cells (ILC) from peripheral blood using flow cytometry. Results: The number of eosinophils (both resting and activated) and chemoattractant receptor homolog expressed on Th2 cells (CRTH2)-expressing CD4 + and CD8 + T cells decreased significantly in EA patients after altitude treatment. The frequency of CRTH2 + Tregs as decreased significantly in all the asthma phenotypes as well as the frequency of ILC2 was significantly reduced in EA after altitude treatment. After 21 days of altitude therapy, CRTH2-expressing ILC2, CD4 + and CD8 + T cells and Treg cells showed attenuated responses to exogenous PGD2. Furthermore, PGD2 signaling via CRTH2 was found to diminish the suppressive function of CRTH2 + Tregs which partially normalized during high-altitude treatment. Improved asthma control was particularly evident in allergic asthma patients and correlated with decreased frequencies of CRTH2 + Treg cells in EA patients. Serum IL-5 and IL-13 decreased during climate treatment in asthma patients with high baseline levels. Conclusions: Asthma treatment in high altitude reduced the type 2 immune response, corrected the increased CRTH2 expression and its dysregulated functions. | 85 BOONPIYATHAD eT Al.

Advances and recent developments in asthma in 2020

“…158Several earlier studies have highlighted the impact of high-altitude treatment in atopic dermatitis and asthma 159,160. A recent study by Boonpiyathad et al161 described the clinical and immunological changes after high-altitude treatment in asthma patient subgroups and showed that clinical improvement is dependent on the asthma phenotype. Furthermore, high-altitude treatment reduced the type 2 immune response and corrected the elevated CRTH2 expression and its dysregulated functions 161.…”

High-Altitude Treatment in Rhinitis Patients

“…There is compelling evidence of a close relationship between rhinitis and asthma. [2][3][4] Epidemiological studies have shown that most of the patients with asthma have concomitant rhinitis, and the presence of rhinitis is an increased risk factor for the development of asthma. [2][3][4] Patients with asthma and rhinitis share common physiopathologic mechanism including heightened airway hyperresponsiveness and heightened reactivity to lots of stimuli.…”

“…[2][3][4] Epidemiological studies have shown that most of the patients with asthma have concomitant rhinitis, and the presence of rhinitis is an increased risk factor for the development of asthma. [2][3][4] Patients with asthma and rhinitis share common physiopathologic mechanism including heightened airway hyperresponsiveness and heightened reactivity to lots of stimuli. [2][3][4] Therapeutic studies have demonstrated that the treatment of rhinitis can improve asthma and vice versa.…”

“…[2][3][4] Patients with asthma and rhinitis share common physiopathologic mechanism including heightened airway hyperresponsiveness and heightened reactivity to lots of stimuli. [2][3][4] Therapeutic studies have demonstrated that the treatment of rhinitis can improve asthma and vice versa. Recently, in Boonpiyathad's study, asthma treatment in high altitude simultaneously improved asthma control, forced expiratory volume in 1 second (FEV1) and exhaled nitric oxide (FeNO), while modifying the immunological characteristics of effector cells known to contribute to eosinophilic and allergic inflammation.…”

“…Recently, in Boonpiyathad’s study, asthma treatment in high altitude simultaneously improved asthma control, forced expiratory volume in 1 second (FEV1) and exhaled nitric oxide (FeNO), while modifying the immunological characteristics of effector cells known to contribute to eosinophilic and allergic inflammation. 2 Accordingly, we hypothesize that high-altitude therapy is an effective treatment for rhinitis.…”