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).