Effects of theophylline combined with inhaled corticosteroids on patients with moderate and severe asthma and changes of T lymphocyte subsets in peripheral blood.

Introduction: Asthma is a common respiratory disease. Theophylline combined with inhaled corticosteroids (ICS) is a promising therapy for asthma. This study explored the therapeutic effects of ICS combined with theophylline on moderate and severe asthma patients and T lymphocyte subsets (CD3⁺CD8⁺ T cells) in peripheral blood.

Material and methods: A total of 202 moderate and severe asthma patients were selected, with 101 treated with theophylline combined with ICS and 101 treated with ICS alone as controls. Lung function [forced expiratory volume within 1 second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF)] were tested using a spirometer. Asthma symptom control was evaluated by asthma control tests (ACT). The life quality was evaluated using the Asthma Quality of Life Questionnaire (AQLQ). The number and percentage of CD3⁺ T, CD3⁺CD4⁺ T and CD3⁺CD8⁺ T cells in peripheral blood mononuclear cells were assessed by flow cytometry. The correlation between CD3⁺CD8⁺ T cells and lung function and asthma control of patients after combination therapy was analyzed by Pearson correlation analysis.

Results: Compared with moderate and severe patients treated with ICS alone, theophylline improved the efficacy of ICS. Theophylline combined with ICS decreased IL-4 and IL-6 levels, and CD3⁺ T and CD3⁺CD8⁺ T cell number and percentage. After combined treatment, CD3⁺ CD8⁺ T cells in peripheral blood of patients were positively correlated with lung function and negatively correlated with asthma control.

Conclusions: The additional use of theophylline improved the efficacy of corticosteroids in asthma patient treatment and reduced inflammation level and CD3⁺ T and CD3⁺CD8⁺ T cell contents in peripheral blood.