Patients With Bronchiectasis Linked to Tuberculosis May Develop More Severe Disease

Patients With Bronchiectasis Linked to Tuberculosis May Develop More Severe Disease

People who develop bronchiectasis after contracting tuberculosis tend to have a more severe form of the disease than those in whom bronchiectasis developed from an unknown cause or is linked to other illnesses, a study has found.

However, the mortality rate, number of hospitalizations, and frequency of acute exacerbations were identical across bronchiectasis causes.

The study, “Performance of Multidimensional Severity Scoring Systems in Patients with Post‐Tuberculosis Bronchiectasis,” was published in the International Journal of Chronic Obstructive Pulmonary Disease.

Tuberculosis is a respiratory infection caused by the bacteria Mycobacterium tuberculosis. Although its global incidence has been decreasing in recent years, those who have had tuberculosis are still at a higher risk of death, mostly due to permanent lung lesions caused by the disease.

Tuberculosis is also one of the most common causes of bronchiectasis, in which the bronchi — small lung airways — become inflamed and progressively thicker due to repeated infections.

To examine the link between tubercolosis and brochiectasis more fully, investigators in Saudi Arabia compared clinical data and outcomes of patients who developed bronchiectasis after contracting tuberculosis to those in whom bronchiectasis was associated with other diseases, or had an unknown cause (idiopathic bronchiectasis).

“As post-[tuberculosis] patients are at increased risk of mortality, it is important to understand the resulting pulmonary complications to improve patient care efforts for this high-risk patient group,” the researchers wrote.

They also compared the performance of several bronchiectasis severity scoring systems normally used to estimate the risk of mortality, hospitalizations, and exacerbations (flare-ups), namely the Bronchiectasis Severity Index (BSI), the FACED score, and two of its variants — Exa-FACED and E-FACED.

The team analyzed data from 301 patients with bronchiectasis, whose medical records had been stored in the King Abdulaziz Medical City-Riyadh bronchiectasis research database between January 2010 and December 2018.

A total of 129 participants (43%) developed bronchiectasis after contracting tuberculosis, 76 (25%) had idiopathic bronchiectasis, and 96 (32%) had bronchiectasis associated with other illnesses.

Over the study period, 52% of the patients with post-tuberculosis bronchiectasis, 29% of those with idiopathic disease, and 30% of the group with bronchiectasis due to other causes were hospitalized.

In the group of patients who developed bronchiectasis after having tuberculosis, 61% were women, with a mean age of 68 years. A little over a quarter (26%) of them had Pseudomonas aeruginosa, a species of bacteria that frequently causes lung infections in bronchiectasis patients.

In general, compared with patients with idiopathic disease or bronchiectasis associated with other diseases, those who developed the disease after having tuberculosis tended to be older, had higher disease severity scores, and were more likely to experience severe disease flare-ups that required hospitalization.

Specifically, 58% of the patients had at least two acute flare-ups within a year. A total of 63 (21%) patients died over the course of the study. The five-year mortality was 30% in the post-tuberculosis group, 18% in people with idiopathic bronchiectasis, and 10% in patients with bronchiectasis from other causes.

However, after normalizing data to take into account disease severity, no significant differences were found between the three groups of patients in mortality rates, number of hospitalizations, or frequency of exacerbations.

Data also showed that all four of the scoring systems could be efficiently used to predict five-year mortality. However, both variants of the FACED score outperformed the original FACED version to estimate the frequency of acute flare-ups and hospitalizations, while the BSI surpassed all the previous three in this regard.

Among the study’s limitations, the team mentioned recruiting patients from a subspecialty clinic with a small number of post-tuberculosis bronchiectasis, which limits generalizing the findings to other populations and settings. In addition, patients with multiple major coexisting conditions were excluded from the study.

“In conclusion, post-TB bronchiectasis patients were older and had higher severity scores compared to idiopathic bronchiectasis patients and patients with bronchiectasis arising from other causes,” the researchers wrote. “Future prospective research in larger cohorts from diverse geographical areas is necessary to confirm these findings.”