Effect of topical fluticasone propionate on the mucosal allergic response induced by ragweed allergen and diesel exhaust particle challenge

Glucocorticoids block the local allergic response in a variety of ways. How ever, studies have also shown that glucocorticoids increase in vitro IgE sy nthesis and that treatment with corticosteroids may result in elevated seru m IgE concentrations. The ability of topical glucocorticoids to modulate th e mucosal IgE response has not been elucidated. We studied the effect of to pical steroid (fluticasone propionate) treatment on the local allergic anti body response induced by challenge with either allergen or diesel exhaust p articles (DEP). A parallel group study was performed with ragweed-allergic subjects, each subject serving as his/ her own control. Nasal provocation c hallenges were performed on three groups. One group received ragweed allerg en, another diesel exhaust particles, and the third saline. The study was r epeated following 1 week of treatment with intranasal fluticasone propionat e. Each group received the same challenge as before. The concentrations of total immunoglobulins (IgE, IgG, IgA, and IgM), anti-ragweed. antibody, IgE - and IgA-secreting cells, epsilon (epsilon) mRNA, and cytokine mRNAs (IL-2 , -4, -5, -6, TNF-alpha, INF-gamma) were measured in nasal lavages performe d before and at various time points after challenge. Treatment with flutica sone propionate for 7 days caused a decrease in the concentrations of nasal IgE protein, IgE-producing cells, total epsilon mRNA, and all the cytokine mRNAs tested. Furthermore, treatment with fluticasone propionate inhibited the production of allergen-specific IgE and cytokine mRNAs following chall enge with ragweed antigen. However, fluticasone treatment did not significa ntly inhibit the enhancement of mucosal IgE production or cytokine mRNAs ob served following nasal challenge with DEP. These results indicate that 1-we ek treatment with topical fluticasone propionate was effective in blocking local effects of allergen exposure but was unable to inhibit the adjuvant-l ike effect of DEP. (C) 1999 Academic Press.