Steroid-induced changes of eosinophils in atopic dermatitis

We investigated whether apoptosis of eosinophils is specific to atopic dermatitis (AD), or also occurs in other diseases with eosinophilia. We examined the survival of eosinophils cultured with corticosteroids: (1) Clinically, steroid administration significantly decreased high peripheral blood eosinophil cell counts in patients with AD. (2) Treatment with recombinant human (rh) IL-5 prolonged the life span of eosinophils derived from patients with AD and of those derived from non-AD patients with eosinophilia. However, there were differences in the survival rates in the presence of rhIL-5: the eosinophils from non-AD patients showed 1.4-fold higher survival rates than those from AD patients at 24 h. In the presence of steroids, the eosinophils from non-AD patients showed a survival rate double that of those from AD patients at 24 h. (3) In eosinophils from patients with AD, the survival rate decreased significantly in a time- and steroid-concentration-dependent manner. Steroid administration significantly inhibited the survival rate of eosinophils from patients with AD compared to those of monocytes and neutrophils. These findings suggest that apoptosis induced by steroids decreases the eosinophil count in vivo in patients with AD. There may be a difference in the incidence of steroid-induced apoptosis between eosinophil cells from patients with AD and those from patients with eosinophilia due to other underlying diseases.