A research team recently reported three parameters – male gender, a history of tuberculosis and increased levels of serum T-IgE – as independent risks factors for the coexistence of bronchiectasis in patients with chronic obstructive pulmonary disease (COPD).
The study “Factors associated with bronchiectasis in patients with moderate–severe chronic obstructive pulmonary disease,” was published in the journal Medicine.
Several studies had already reported an association between bronchiectasis and more severe symptoms, higher frequency of exacerbations, and mortality; which led the Global Initiative for Chronic Obstructive Lung disease (GOLD) to declare bronchiectasis as one of the comorbidities of COPD. Supporting information came from high-resolution computed tomography (HRCT), increasingly used in the assessment of COPD, that detected more frequent cases of bronchiectasis in COPD patients.
While risk factors for bronchiectasis in COPD patients had been poorly characterized, researchers for the recent study aimed to determine risk factors for bronchiectasis in a well-defined cohort of patients with stable moderate to severe COPD. Patients underwent HRCT and two radiologists evaluated the results for the presence and extent of bronchiectasis.
Researchers also evaluated other parameters in the two groups of patients with and without bronchiectasis: demographic data, respiratory symptoms, lung function, previous pulmonary tuberculosis, serum inflammatory markers, serum total immunoglobulin E (T-IgE, antibodies produced by the immune system in response to an allergic reaction), and sputum culture of Pseudomonas aeruginosa bacteria.
The study included 190 patients with stable COPD, from which 87 (45.8%) were diagnosed by HRCT to have bronchiectasis.
Researchers observed that when compared to patients without bronchiectasis, COPD patients with bronchiectasis were more likely to be males. The patients also carried significant lower body mass index, higher prevalence of previous cases of tuberculosis, a longer and more severe history of dyspnea, a higher frequency of acute exacerbation, and higher serum concentrations of systemic inflammatory markers such as C-reactive protein and fibrinogen.
When assessing patients’ lung function, COPD patients with bronchiectasis showed poorly. They also showed higher positive rates for bacteria in sputum samples.
An analysis of all parameters revealed that being male, having had previous tuberculosis, and exhibiting increased levels of serum T-IgE are independent risk factors for the coexistence of bronchiectasis and COPD.
The researchers concluded that the study showed a connection between higher serum T-IgE levels and the presence and severity of bronchiectasis in patients with moderate to severe COPD. And they suggest that therapeutic strategies to target IgE production and action are potential approaches for reducing symptoms and improving bronchiectasis in patients with COPD.