ABSTRACT
The most important factors in the pathogenesis of bronchial asthma and chronic bronchitis is the immunoregulation and allergies including extrinisic bronchial asthma may arise through a defect in one or more of this immunoregulatory mechanisms. This work was done on 23 patients diagnosed as extrinsic bronchial asthma and 16 patients diagnosed as chronic bronchitis. H/S ratio was estimated for each case. The difference in the helper/suppressor ratio between the 2 diseases reflect the changes in the helper and suppressor cells. The ratio is significantly higher than normal in bronchial asthma, while lower in chronic bronchitis. The main difference is the decrease of suppressor T-cells in bronchial asthma reflected on the high level of IgE in such patients due to the release of the suppressor effect on the helper cells