Effects of oral steroids on blood CXCR3+and CCR4+T cells in patients with bronchial asthma

Corticosteroids are widely used in bronchial asthma, but their mechanism of action is not fully understood. The in vitro studies have proposed that hu man T helper cells, type 1 (Th1) favor expression of CXCR3, whereas Th2 cel ls favor CCR4. In this study we investigated whether oral prednisolone modu lates the balance of peripheral blood CXCR3+ and CCR4+ T cells. We analyzed the T-cell subsets in 28 patients with stable atopic asthma and 13 normal control subjects before and after 2 wk of treatment with prednisolone, 20 m g/d, or placebo in a randomized, double-blind, parallel group study. The nu mbers of CXCR3+ and CCR4+ memory T cells were measured with a flow cytomete r, and expressed as percentages in CD4+/CD45RO+ memory T cells. In the ster oid-treated asthma group, there was a decrease in CCR4+ T cells (from 29.3% to 20.3%, p < 0.0001), and an increase in CXCR3+/CCR4+ ratio (from 1.86 to 2.89, p = 0.0047), whereas there was no change in CXCR3+ T cells. However, the percentages of CCR4+ cells did not change after steroid therapy in nor mal control subjects. These results suggest that short-term oral corticoste roid modulates the balances of CXCR3+ and CCR4+ cells in patients with asth ma.