Tiotropium use and pulmonary function in patients with constrictive bronchiolitis

Tiotropium, a long-acting muscarinic antagonist bronchodilator with well-established use in COPD, has recognized activity in reducing lung hyperinflation, as well as in relieving dyspnea and improving exercise capacity in this population of patients. In a recently published article, (2) tiotropium was shown to be able to attenuate TGF-β-induced airway remodeling. In addition, the combination of albuterol and tiotropium has been shown to elicit an acute response in patients with constrictive bronchiolitis (CB) secondary to graft-versus-host disease after bone marrow transplantation, there being a significant variation in FEV 1 , FVC, or both, in 7 of 17 patients tested. Therefore, smooth muscle plays a significant role in CB, and tiotropium might have an inhibitory activity on bronchoconstriction and airway remodeling. µg; once a day for 30 days) to 11 consecutive patients with CB. The diagnosis of these patients is described below. Simple spirometric tests were performed before and after tiotropium use, in accordance with the Brazilian guidelines for pulmonary function testing, (4) and 6 patients underwent pre-treatment plethysmography. Eight patients were female, with the mean age at diagnosis being 49 ± 11.6 years and the mean age at initiation of tiotropium therapy being 54.9 ± 11.0 years. Six patients had a history of smoking, but only 2 had a history of greater than 5 pack-years. Nine patients had a history of significant exposure (mold, metallurgical material, birds, herbicides, paints, seeds, and plaster). Three patients had a collagen disease (rheumatoid arthritis, in 1; Sjögren's syndrome, in 1; and both, in 1); for these three patients, collagen disease was considered the major etiological factor. All patients underwent chest CT, which revealed direct signs of small airway disease (bronchial wall thickening, bronchiectasis, bronchiolectasis, centrilobular micronodules or opacities with a tree-in-bud pattern) in 9 patients and an indirect sign of small airway disease (mosaic attenuation) in 2 patients. Seven biopsies (six surgical biopsies and one transbronchial biopsy) were performed, all of which showed the presence of CB. The 3 patients with rheumatic disease did not undergo lung biopsy because their clinical, functional, and CT findings were consistent with small airway disease, whereas 1 patient did not undergo biopsy because of his severe clinical status, but this patient had clinical, functional, and CT findings of CB. The treatments instituted before the initiation of tiotropium therapy were as follows: systemic corticosteroid therapy, in 8 patients; inhaled corticosteroid therapy, in 7; long-acting β 2 agonist therapy, in 4; …