T-regulatory cells blood content in patients with asthma exacerbation

Background: Regulatory CD4+CD25+ T cells are important components of the immune system homeostasis and impairment of their activity can cause autoimmune diseases and allergy. Objective: The aim of this study was to evaluate the blood content of naturally occurring T-regulatory cells (nTreg) in patients with different periods of asthma. Methods: 48 steroid naïve asthmatic adults with asthma exacerbation and 48 with asthma remission were randomly selected and 30 matched control subjects were included. All were submitted to detailed clinical history and examination, pulmonary function testing. Investigation of CD4+, CD25+, CD4+CD25hi-lymphocytes in blood was carried out by flow cytometry. nTreg were defined as a fraction of CD4+CD25+-lymphocytes with a high level of CD25 expression (CD4+CD25hi-cells). Results: Subjects with asthma exacerbation had significantly lower values of CD4+CD25hi-cells than subjects with asthma remission (1,56 (1,14-1,97)% vs 5,90 (4,96-6,71)%; p<0,001) and controls (1,56 (1,14-1,97)% vs 7,40 (6,41-8,52)%; p<0,001). Subjects with asthma remission had also significantly lower values of CD4+CD25hi-cells than controls (5,90 (4,96-6,71)% vs 7,40 (6,41-8,52)%; p<0,001). Conclusion: CD4+CD25hi-cells blood content is decreased in asthma in comparison with healthy subjects. Blood content of CD4+CD25hi-cells in asthma exacerbation decreases 3 fold and more in comparison with remission and can be predictor for asthma exacerbation.