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 eosinophils-basophils 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, I-309 (CCL1), MCP-1 (CCL2), MIP1-alpha (CCL3), MIP1-beta (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-alpha and MIP1-beta 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.