Peculiarities of mucociliary system functioning in patients with chronic obstructive pulmonary disease during treatment with tiotropium bromide

Abstract

Functioning of mucociliary system (MCS) including integral rate of tracheobronchial mucociliary clearance (MCC) using dynamic perfusion-lung scanning, ciliary activity in bronchial biopsy specimens and viscous and elastic properties of bronchial mucus was studied in 128 patients with chronic obstructive pulmonary disease (COPD). Of them, 90 % had mucociliary insufficiency (MCI), the intensity of which was in direct proportion to the disease severity. Development of MCI was caused by decrease in ciliary beat frequency, increased viscosity of bronchial mucus and active inflammation identified during bronchoscopy. While considered correlations between these parameters and integral rate of MCC, a method for detection of MCI has been proposed based on the solution of a discriminant equation; this method allows diagnosing MCI with 81 % of probability. Changes of MCC rate were investigated in a 6-wk prospective comparative randomized controlled trial in 69 patients with stage II COPD under different therapies according to GOLD recommendations. As a result, functional MCI was improved in 14 of 29 patients (48 %) receiving standard therapy during exacerbation and in stable condition, whereas similar improvement was reached in 28 of 40 patients (70 %) who additionally took long-acting anticholinergic drug tiotropium bromide 18 μg daily. Other 12 patients (30 %) had a weak response of MCC to tiotropium bromide due to low baseline MCC rate. A method predicting effect of tiotropium bromide on MCI in patients with stage II COPD using baseline MCC rate and a discriminant equation has been proposed.