Effects of allergen inhalation and oral glucocorticoid on serum soluble CTLA-4 in allergic asthmatics.

The serum soluble cytotoxic T lymphocyte associated antigen-4 (sCTLA-4) concentration is significantly elevated in patients with asthma, and sCTLA-4 concentration correlate with the severity of asthma. The aim of the present study was to investigate effects of allergen inhalation and oral glucocorticoid on concentration of serum sCTLA-4 in patients with allergic asthma.Allergen inhalation challenge was conducted in allergic asthmatics with isolated early asthma response and those with dual asthma response. In a randomized, double-blind, placebo-controlled, parallel group fashion, prednisolone or placebo was give orally once a day for 2 weeks. Venous blood samples were collected before and after allergen inhalation or prednisolone administration for obtaining sera. The serum sCTLA-4 concentrations were determined using enzyme-linked immunosorbent assay.The serum sCTLA-4 concentrations in the dual responder group increased from 29.0 (14.5–43.7) μg/l [median (25–75 percentiles)] before allergen inhalation to 44.0 (24.3–61.3) μg/l 24 h after allergen inhalation. In the isolated early responders, there were no significant increase in serum sCTLA-4 concentrations after allergen inhalation compared with baseline levels. There was a significant decrease in serum sCTLA-4 concentrations after 2 weeks of glucocorticoid therapy [22.0 (15.5–31.0) μg/l] compared with baseline values [37.0 (19.5–53.0) μg/l], whereas there was no significant difference in the placebo group.This study has demonstrated that serum sCTLA-4 concentrations increased after allergen inhalation in sensitized asthmatic subjects, and that serum sCTLA-4 concentrations were downregulated by prednisolone therapy. [ABSTRACT FROM AUTHOR]