Patients with bronchiectasis have different disease characteristics and bacterial infections depending on the underlying cause of the disease, suggesting that different disease management measures are needed in different groups.
The study, “Phenotyping Adults with Non-Cystic Fibrosis Bronchiectasis: A 10-Year Cohort Study in a French Regional University Hospital Center,” published in the journal Respiration, however, said that more research into the differing characteristics is needed.
The management of infections with the bacterium Pseudomonas aeruginosa was pinpointed as a factor needing more attention, particularly in patients who develop bronchiectasis after chronic obstructive pulmonary disease (COPD).
In the search for varying disease characteristics in bronchiectasis patients, researchers at the Centre Hospitalier Universitaire de Nice in France examined health records of patients at the hospital between 2002–2012. The study included patients with bronchiectasis who were not linked to cystic fibrosis, and who had their disease confirmed through a chest computed tomography (CT) scan.
Most patients, 245 of 311, had been examined in the search for a known cause of their disease. Two-thirds of the patients were women and the median age of diagnosis was 61.
Half the patients developed bronchiectasis after an infection, most often tuberculosis. The most common non-infectious cause of bronchiectasis was COPD, affecting 13 percent, but other causes such as congenital reasons, immune deficiency, asthma, tumors, or autoimmune conditions were also noted. In 11 percent of the patients, doctors could not find a cause despite examinations.
Bronchiectasis related to COPD was most common in men, of whom the vast majority, 94 percent, were former or active smokers. These patients were also older and had the lowest lung function values at diagnosis. The most common bacterial infection in this group was Pseudomonas aeruginosa, found in 65 percent.
Those who had a congenital problem causing their bronchiectasis were the youngest among patients when they received a diagnosis, and only 13 percent smoked. Nearly all (93 percent) had airways colonized by harmful bacteria, of which more than half were P. aeruginosa.
Patients with no known cause underlying their bronchiectasis were most often women, and few of them smoked. They also had the best lung function at diagnosis.
Researchers also examined the impact of Pseudomonas infection by comparing patients with the bacteria to those with other infections or a normal airway bacterial flora. Pseudomonas was linked to lower lung function levels at diagnosis, and researchers noted that patients with the infection tended to decline more rapidly, although the results were not statistically significant.
About 20 percent of patients were occasionally coughing blood, but this was a rare occurrence in those with bronchiectasis caused by autoimmune or immune deficiency conditions, as well as in those without a known disease cause.
Surgical removal of a lung lobe was done in 10 percent of patients and was more common among those with congenital bronchiectasis or patients without a known cause.
Pulmonary hypertension was found in 5 percent of the overall patients and in 16 percent of the COPD patient group.
“Distinctive clinical, functional, and microbiological features were found for idiopathic, congenital and COPD-related bronchiectasis. A prospective follow-up of these subgroups is necessary to validate their relevance in the management of bacterial colonization and specific complications of these bronchiectases,” the team wrote in their report.