Eosinophil Recruiting Chemokines are Down-Regulated in Peripheral Blood Mononuclear Cells of Allergic Patients Treated with Deflazocort or Desloratadine

Abstract

Chemokines are cytokines with chemotactic properties on leukocyte subsets whose modulation plays a key role in allergic inflammatory processes. To better understand the possible anti-inflammatory effects of histamine-1 receptor antagonists in allergic asthma, we studied the mRNA expression of a set of chemokines known to be involved in the eosinophil/basophil activation as well as recruitment and T-cell signaling events, before and after corticosteroid or antihistamine treatment in PBMCs from allergic/asthmatic patients ex vivo. Twelve patients were enrolled, all of whom were allergic to Parietaria judaica and suffering for mild persistent asthma: six were treated with desloratadine (10 mg/day), and six with deflazacort (12 mg/day). Before and after the treatment, PBMC samples were collected from each patient and analyzed for the expression of encoding mRNAs for several chemokines, 1–309 (CCL1), MCP-1 (CCL2), MIP1-α (CCL3), MIP1-β (CCL4), RANTES (CCL5), IL-8 (CXCL8), IP-10 (CXCL10), Lymphotactin (XCL1). Clinical and functional improvements were seen after 3 weeks of therapy; this was associated with a reduced expression in the mRNA levels for the chemokines RANTES, MIP1-α and MIP1-β with either the corticosteroid or the antihistamine, compared to the pre-treatment levels. Chemokine downregulation was statistically significant in both groups of patients. These findings suggest that certain antihistamines may act as down-modulators of allergic inflammation, possibly through a negative regulation of the chemokines involved in activation and attraction of eosinophils. Our results suggest that clinical trials with long follow-ups may be useful in evaluating histamine-1 receptor antagonists as add-on therapy to steroids in the treatment of asthma.