Adults with bronchiectasis with baseline use of inhaled corticosteroids (ICS) had worse clinical outcomes after 1 year, including a lower forced expiratory volume in 1 second (FEV₁) % predicted, higher exacerbation rates, and increased incidence of Pseudomonas aeruginosa isolation, based on data from a new study presented at the World Bronchiectasis Conference.

Bronchiectasis affects an estimated 350,000-500,000 adults in the US, and approximately 40% are prescribed ICS, but the impact of ICS use on bronchiectasis outcomes has not been well studied, said lead author Mikiyas T. Desta, MD, pulmonology critical care fellow at New York Presbyterian/Columbia University Irving Medical Center in New York.

In the study, Desta and colleagues reviewed data from the US Bronchiectasis and Nontuberculosis Mycobacteria (NTM) Research Registry. The study population included 1050 adults with bronchiectasis but without cystic fibrosis (80.3% were female). Of these, 283 (27%) were prescribed ICS at baseline, and these patients had significantly lower baseline FEV₁% predicted than those not prescribed ICS at baseline (70% vs 78%; P < .001). Patients prescribed ICS at baseline also were significantly more likely to have at least one pulmonary or exacerbation-related hospitalization in the prior 2 years (25.8% vs 17%; P = .005) and significantly less likely to have NTM isolated (46.3% vs 64.4%; P < .001) compared with patients without ICS use.

After 1 year, patients with ICS at baseline had significantly lower FEV₁% predicted (72% vs 77%; P = .002) than those not treated with ICS at baseline. The ICS group also was significantly more likely than non-ICS patients to have had at least one exacerbation and at least one exacerbation-related hospitalization (58.3% vs 42.1% and 20.5% vs 10.2%, respectively; P < .001 for both) and significantly more likely to have isolation of P aeruginosa (37.7% vs 28.0%; P = .01).

In the subgroup of patients with baseline NTM positivity, those with ICS had lower FEV₁% predicted, more exacerbations, and were more likely to have P aeruginosa and Staphylococcus aureus isolation at the 1-year follow-up than those without ICS (P < .01 for all).

In the subgroup of patients with baseline P aeruginosa positivity, no significant differences appeared in spirometry, exacerbation, or microbiology at the 1-year follow-up between patients with and without ICS therapy.

Previous analyses of data from the European Bronchiectasis Registry have shown an association between baseline ICS use in bronchiectasis and increased risk for exacerbations and mortality, and the researchers hypothesized that baseline ICS therapy in bronchiectasis would be associated with similarly worse clinical outcomes, including decline in spirometry and more exacerbations.

In keeping with the hypothesis, ICS therapy was associated with adverse clinical outcomes, including in subgroups with asthma, chronic obstructive pulmonary disease (COPD), and NTM for patients with bronchiectasis. “Among patients with eosinophilia, ICS therapy was not associated with significantly different clinical outcomes compared to no ICS use, though our sample size was small,” Desta said. “However, it is important to note that patients with bronchiectasis prescribed ICS therapy had more severe disease at baseline,” he said. The researchers plan to conduct additional data analyses to account for selection bias and to evaluate the impact of ICS use over a longer period, he added.

The results suggest that ICS therapy may need to be used with caution in clinical practice for patients with bronchiectasis and/or NTM, said Desta. “Prospective studies, including randomized, controlled trials, are needed to assess the impact of ICS therapy in bronchiectasis and to determine whether specific subgroups would benefit from ICS therapy, such as those with eosinophilia,” he said.

Revealing Practice Patterns

“The bronchiectasis field is moving towards disease endotyping and phenotyping,” said Shijing Jia, MD, clinical associate professor and medical director of the Bronchiectasis and NTM Care Center at the University of Michigan in Ann Arbor.

“To better understand disease pathophysiology, we need to define how disease characteristics or treatments predict prognosis,” said Jia, who was not involved in the study. The current study is the first step to a broad survey of the practice patterns and outcomes related to ICS use in bronchiectasis in the US, she said.

The relatively low use of routine ICS in patients with bronchiectasis across US sites is reassuring, said Jia. “ICS should be used judiciously, such as in cases where type 2 asthma is present,” she noted. However, the positive culture for NTM in 46% of patients using ICS is concerning, as patients with NTM are a particularly vulnerable population where ICS use is typically minimized, she added.

The findings were limited by the observational study design, but the results suggest that clinicians consider why patients with bronchiectasis who require ICS at baseline are sicker overall, said Jia. “More research is needed to better characterize the impact of ICS use on bronchiectasis outcomes, and future studies should focus on adjusted and/or time-dependent approaches, which may incorporate longitudinal assessments of FEV₁ decline,” she said.

The study was supported by the Bronchiectasis and NTM Association, which is supported by corporate donors including Zambon, Merck, GlaxoSmithKline, Baxter International, Electromed, Inc., Monaghan Medical Corporation, and Tactile Medical.

The researchers reported having no financial conflicts to disclose. Jia disclosed grant support from the National Institutes of Health, the Cystic Fibrosis Foundation (CFF), COPD Foundation, and Cure CF Inc., as well as clinical trials support from AstraZeneca, Boehringer Ingelheim, CSL Behring, Krystal Biotech, Insmed, Merck, Sanofi, Verona Pharma, and Vertex; consulting fees from Boehringer Ingelheim, Insmed, Parexel, and Verona Pharma; royalties/honoraria from CFF and UpToDate; and committee/advisory board participation for CFF.