Markers of allergic inflammation in peripheral blood of children with asthma after treatment with inhaled triamcinolone acetonide.

BACKGROUND: It is important to monitor inflammation regularly in asthma in addition to clinical symptoms, and there is a great need for noninvasive tests that could routinely be used in clinical practice.

OBJECTIVE: Our hypothesis was that the improvement of clinical parameters, together with decreased airway responsiveness, could be correlated with changes in the levels of serum markers of inflammation after a 4-week treatment with triamcinolone.

METHODS: In this double-blind, randomized, placebo-controlled trial, 48 children, aged 6 to 18 years, with mild to moderate atopic asthma, were randomly allocated to receive triamcinolone or matching placebo for 4 weeks. The following parameters were measured: the 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 the inflammatory markers eosinophil cationic protein (ECP), soluble receptor of interleukin-2 (sIL-2R), interleukin-4, soluble intercellular adhesion molecule-1 before and after treatment.

RESULTS: The clinical parameters significantly improved after treatment with triamcinolone; the mean value of FEV1 changed from 74% of predicted value before, to 90% of predicted after treatment (P < 0.001). PC20 for histamine after treatment with triamcinolone increased significantly from the mean value 2.5 mg/mL to 4.7 mg/mL (P < 0.001). Treatment with triamcinolone significantly (P < 0.05) decreased serum levels of all the measured inflammatory markers. The mean concentration of eosinophil blood count was 380 and 261 cells/mm3; ECP, 83 and 58 ng/mL; serum sIL-2R, 734 and 487 pg/mL; soluble intercellular adhesion molecule-1, 266 and 210 ng/mL, before and after treatment, respectively. The values of interleukin-4 were low and close to the sensitivity of the assay. A significant correlation was found between ECP and sIL-2R levels before and after treatment with triamcinolone.

CONCLUSIONS: A significant decrease of all the measured serum parameters was observed after treatment with triamcinolone; however, no significant correlation was found among any of those parameters and clinical markers of disease severity (such as FEV1 or PC20H).