Children diagnosed with non-cystic fibrosis bronchiectasis since 2002 have better lung function at diagnosis, distinct disease causes, and higher frequency of sputum infections, compared to children followed in the same center years earlier, a Turkish study found.
The study, “Changing clinical characteristics of non-cystic fibrosis bronchiectasis in children,” was published in the journal BMC Pulmonary Medicine.
Bronchiectasis often occurs secondary to another medical condition such as cystic fibrosis, pulmonary disorders, respiratory tract infections, and allergies. But with increases in vaccination programs that prevent pulmonary infections and increased access to healthcare, the causes leading to bronchiectasis appear to have changed in the past couple of decades.
Researchers at the Marmara University, School of Medicine, Turkey, set out to assess causes and other disease features in children with non-cystic fibrosis bronchiectasis followed at their clinic from 2002 to 2019. For comparison, they examined a previously described group of children followed in the same clinic from 1987 to 2001.
The most recent group included 104 children, a nearly equal mix of boys and girls, with a median age of 8 years. They had been diagnosed at a median age of 7, presenting mostly with symptoms of cough (95.2%), sputum, or thick mucus (77.9%), shortness of breath (51%), and wheezing (42.3%).
The recent and historical groups were fairly similar, except that patients diagnosed from 2002 onward had a significantly lower frequency of finger clubbing (enlargement of fingertips) and better lung function.
This suggested a milder form of bronchiectasis, the researchers said. “Possible explanations for these changes may be due to increased annual income, better vaccine coverage, earlier recognition and referral and improved access to health care,” they wrote.
During follow-up, done at three-month intervals over one year, the annual rate of pulmonary exacerbations decreased from 6.05 at presentation to 3.23. A similar result was seen in the historical group.
However, while the forced expiratory volume for one-second (FEV1%) increased over time in the historical group from 63.3% to 75.2%, it remained the same in patients diagnosed more recently — 76.6% at presentation and 77% at the end of follow-up.
In total, researchers identified a cause for bronchiectasis in 80.8% of patients, which was significantly higher than the 62.2% of people with a known cause in the historical group. This was due mostly to an increase in cases related to primary ciliary dyskinesia (PCD) — 32.7% vs. 6.3% in the historical group.
PCD is a condition in which abnormal cilia and flagella — small hair-like projections in cells — cannot effectively clear out mucus and pathogens from the lungs, causing chronic respiratory tract infections. The team believes the greater higher rate of PCD-related bronchiectasis was a consequence of better diagnostic methodologies and genetic analysis that enabled earlier diagnosis of PCD.
Bronchiectasis was located mostly in the left lower lobe in both groups, and the amount of patients with involvement of one lobe, two lobes, or multiple lobes was not significantly different between groups. However, results showed a trend toward a lower involvement of multiple lobes and higher two-lobe involvement in the most recent group of patients.
Children followed from 2002 had a higher rate of microbial infections in their mucus (77.9% vs. 46.9%), possibly “due to the better qualified staff and equipment in microbiology laboratories leading to more accurate laboratory identification of the microbiology results,” the team wrote.
The most frequently isolated bacteria in children diagnosed more recently were Haemophilus influenzae (71.8%), Streptococcus pneumonia (47.1%), and Moraxella catarrhalis (14.4%), all of which were significantly more frequent in the new group compared to the historical group.
Finally, the researchers found that children were treated less frequently with surgery in more recent years, compared to those followed before 2002.
“There were significant differences between the pulmonary function tests at diagnosis and follow-up, underlying etiology, and rate of positive sputum microbiology between the recent and historical cohorts,” the scientists wrote.
“As the availability of non-invasive and effective diagnostic technologies increase, the detection rate of underlying etiology [cause] will increase and improve the outcomes of non-CF [cystic fibrosis] bronchiectasis,” they concluded.