Background Levels of an immunoregulatory and anti-inflammatory cytokine IL-10 are reduced in asthmatic airways, potentially contributing to more intense inflammation. Triamcinolone has anti-inflammatory properties and the anti-inflammatory effects of montelukast and formoterol have been discussed.
Objective The purpose of this study was to define the effect of treatment with triamcinolone, montelukast and formoterol on the serum level of IL-10, eosinophil blood counts, eosinophil cationic response (ECP) and clinical parameters (symptom score, FEV1 and PC20H) in children with moderate asthma.
Methods An 8-week, placebo-controlled and randomized, double-blind trial was carried out. The subjects were 91 children with moderate atopic asthma who were allergic to dust mite. Patients were randomly allocated to receive 400 µg triamcinolone (n = 19), 5 or 10 mg (according to age) montelukast (n = 18), 24 µg formoterol (n = 18) or placebo (n = 36).
Results Seventy-nine children completed the study. After treatment with triamcinolone and montelukast the level of IL-10 in blood serum significantly increased, eosinophil blood counts and ECP levels significantly decreased and all clinical parameters improved; treatment with formoterol had no effect on IL-10 level, eosinophil blood counts in serum and bronchial hyper-reactivity; ECP level significantly decreased after treatment and asthma symptoms and FEV1 improved significantly. Mean IL-10 levels in serum before and after treatment with triamcinolone were 7.23 pg/mL with 95% CI, 6.74 –7.72% and 14.24 pg/mL with 95% CI, 11.6–16.88%, respectively (P < 0.001); with montelukast they were 6.59 pg/mL with 95% CI, 6.26–7.23% and 10.94 pg/mL with 95% CI, 8.24–12.65%, respectively (P < 0.002); with formoterol they were 7.06 pg/mL with 95% CI, 6.61–7.52% and 7.04 pg/mL with 95% CI, 6.15–7.93%. We found statistically significant correlations between serum level of IL-10 and serum level of ECP after treatment with triamcinolone and montelukast.
Conclusion This study demonstrates that one possible way by which triamcinolone and montelukast contribute to inhibition of inflammation is by increasing IL-10 levels.