Bronchial asthma（abbreviated as "asthma"） is a common airway inflammatory disease. T lymphocyte subsets play an important role in the pathogenesis of airway inflammation

and the imbalance between effector T cells and regulatory T cells of immune system has been shown to be involved in the mechanism of asthma. In traditional Chinese medicine

"latent phlegm" is considered to be the perennial root of the lingering asthma

which is caused by depletion of healthy qi and the following spleen deficiency leading to the loss of transformation. Therefore

it is crucial to fortify the spleen

boost qi

reinforce healthy qi and dispel latent phlegm in treating asthma. As latent phlegm is similar to what is called asthma airway inflammation in modern medicine

the immune mechanism of spleen-fortifying and qi-boosting method in treating asthma can be explored from the perspective of regulating the imbalance of T lymphocyte subsets. The improvement of regulatory T cells function and its balance with effector T cells may explain the mechanism of action of spleen-fortifying and qi-boosting method.