Background and purpose: Allergic asthma is a chronic inflammatory disorder with increased inflammation and bronchial over react to stimulants. Th1 and Th2 cells are the main cells involved in the pathophysiology of asthma. The function of these cells is under the influence of T-bet and GATA3 transcription factors. This study aimed to investigate the impairment of immune responses in patients with allergic asthma compared with controls.

Materials and methods: In a case-control study, 24 patients with allergic asthma and 10 healthy individuals were recruited. The Mononuclear cells (PBMCs) were isolated and cDNA was synthesized after RNA extraction. Gene’s expressions of T-bet and GATA3 were evaluated by Real-time Polymerase chain reaction and their relationships with risk factors for asthma were analyzed using statistical tests.

Results: In our study, the GATA3 gene expression in patients increased 29 times more than that in controls (P= 0.002) but the expression of T-bet declined (0.43, P =0.32). Evaluation of T-bet / GATA3 showed that this ratio was significantly lower in patients compared with that in the controls (P<0.0001).

Conclusion: Increased expression of GATA3 and significant reduction of T-bet / GATA3 ratio in patients showed disturbed immune responses in asthma. So, any remedial or control actions should focus on improving the unbalanced situation.