The effect of of glucocorticoids on grain dust-induced airway disease.

STUDY OBJECTIVES

To determine the effect of glucocorticoids on grain dust-induced airflow obstruction and airway inflammation.

DESIGN

Randomized controlled trial.

SETTING

University hospital.

PARTICIPANTS

Health volunteers.

INTERVENTIONS

Two randomized, placebo-controlled trials, each studying 10 healthy volunteers who were pretreated with either triamcinolone acetonide (Azmacort) oral inhaler 4 puffs twice daily (800 microg daily) for 7 consecutive days or IV hydrocortisone (3 microg/kg/min) as a 14-h continuous infusion, then subjected to a controlled inhalation exposure to corn dust extract (CDE) (endotoxin exposure dose of 3 microg/kg). A single-blind, crossover study design was performed for each trial enrolling 10 healthy, lifetime nonsmokers, with no history of lung disease or environmental exposure to grain dust.

MEASUREMENTS AND RESULTS

Following each inhalation exposure to CDE, spirometry was performed at regular intervals and BAL was performed at 4 h. Both treatment and placebo groups demonstrated significant decrements in spirometry and increments in BAL cellularity following CDE inhalation compared with placebo. Inhaled steroid treatment resulted in a significantly higher FEV1 only at the 2-h time point following CDE inhalation with no significant differences observed in the BAL total cell concentration or cellular differential compared with placebo. IV hydrocortisone treatment resulted in a significantly higher FEV1 and FVC between 2 and 4 h after CDE inhalation, as well as significant reductions in the BAL total cell, macrophage, and eosinophil concentrations. Interestingly, the concentration of tumor necrosis factor-alpha and interleukin-8 in the BAL fluid was also decreased following treatment with IV glucocorticoids.

CONCLUSIONS

These results demonstrate that glucocorticoids, administered IV and perhaps by inhalation, have a mildly protective effect on airflow obstruction and airway inflammation induced by inhalation of grain dust.