Bitter taste receptors in serum of patients with asthma (a hypothesis)

Recently, bitter taste receptor (TAS2R) expression has been found in the respiratory system, but function of these receptors is largely unknown. The aim of our study was to assess serum concentration of TAS2R38 bitter taste receptors in patients with asthma. Methods. We examined 49 patients with asthma and 33 healthy individuals. Asthma was diagnosed according to GINA, 2016. Bitter taste receptor (TAS2R) expression was measured in paired samples using the immunoenzyme analysis. Results. Bitter taste receptor (TAS2R) expression levels significantly differed between healthy males and healthy females with the highest values in females. Bitter taste receptor (TAS2R) expression level was twice lower in female patients with atopic asthma compared to the healthy females. This parameter did not differ significantly between both males and females with non-atopic asthma compared to controls and to atopic asthma patients. Serum concentration of TAS2R38 bitter taste receptors was related to blood cell counts (lymphocytes, monocytes, neutrophils). In patients with non-atopic asthma, serum concentration of TAS2R38 bitter taste receptors was related to sputum count of ciliated cells. TAS2R38 receptor concentration was also related to some infectious upper airway diseases (pharyngitis, tonsillitis) in females with atopic asthma. Lung function parameters (peak expiratory flow and the maximal expiratory flow at 50% of the forced vital capacity) were inversely related to TAS2R38 receptor concentration. Conclusion. We suppose that soluble serum TAS2R38 bitter taste receptors could probably act as negative regulators and contribute to the inflammation in asthma.

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