A randomized, double-blind trial of the effect of treatment with formoterol on clinical and inflammatory parameters of asthma in children.

BACKGROUND

In addition to their bronchodilating effect, long-acting inhaled beta-agonists have recently been shown to have some anti-inflammatory properties.

OBJECTIVE

The purpose of this study was to evaluate the effect of formoterol on inflammatory mediators in children.

METHODS

In this double-blind, randomized, placebo-controlled trial, 34 children, aged 6 to 18 years, with moderate atopic asthma, were randomly allocated to receive formoterol or matching placebo for 4 weeks. The primary endpoint of this study was to determine changes in serum levels of inflammatory markers after treatment with formoterol; secondary endpoints included clinical efficacy and bronchial hyperreactivity. The following parameters were measured: symptom score, forced expiratory volume in 1 second (FEV1), provocative concentration of histamine causing a 20% fall in FEV1 (PC20) for histamine and peripheral blood eosinophil count, serum levels of eosinophil cationic protein (ECP), soluble receptor of interleukin-2 (sIL-2R), level of interleukin-4 (IL-4), level of soluble intercellular adhesion molecule-1 (ICAM-1), and immunoglobulin E (IgE) level before and after treatment.

RESULTS

Compared with placebo, treatment with formoterol significantly improved lung function. The mean value of FEV1 changed from 74% of predicted value before treatment to 80% of predicted value after treatment (P < 0.001). The mean concentration of eosinophil blood count before and after treatment was 379 and 310 cells/mm3 (P = 0.035); ECP was 93 and 83 mcg/L; and serum IL-4 was 0.13 and 0.11 pg/mL (P = 0.001). There was no significant difference between formoterol and placebo recipients in PC20H, and serum concentration of sIL-2R, sICAM-1, or IgE after treatment. The group that received formoterol showed improvement in pulmonary function as measured by FEV1 (P < 0.001), and PC20H (P = 0.04) after 4 weeks of treatment. These patients also showed improvement of clinical symptoms (P < 0.001). Serum marker measurements in the formoterol group showed decreased concentrations of eosinophil blood count, ECP, and IL-4, but there was no difference in before and after measurements of sIL-2R, sICAM-1, and IgE.

CONCLUSIONS

These results indicate that formoterol has measurable anti-inflammatory properties and can diminish asthma symptoms and bronchial hyperreactivity.