Chronic infection by the fungus Aspergillus fumigatus occurs frequently among people with non-cystic fibrosis (CF) bronchiectasis and warrants routine monitoring, a study suggests.
The study, “Sensitization to A.fumigatus in subjects with non‐cystic fibrosis bronchiectasis,” was published in the journal Mycoses.
Bronchiectasis can be acquired genetically, as in CF, or as a consequence of other illness, such as tuberculosis (TB).
Although fungal infections often occur whatever the disease’s cause, there is little systematic data covering sensitization with A. fumigatus — meaning repeated exposure makes a person increasingly infection-prone — in non-CF bronchiectasis cases. Scientists also do not yet know whether certain causes of bronchiectasis carry higher risk for sensitization.
Researchers at the Postgraduate Institute of Medical Education and Research, in Chandigarh, India, examined the rates of sensitization and of chronic infection by A. fumigatus in non-CF bronchiectasis patients.
Between January 2018 and January 2020, they identified 258 patients with acquired bronchiectasis. Their mean age was 42 and mean duration of symptoms was 6.3 years.
TB was the most common cause of bronchiectasis, accounting for 155 cases (60.1%), followed by idiopathic or unknown cause cases, (66, 25.6%). Causes of the remaining 37 cases included primary ciliary dyskinesia, Swyer-James syndrome, and rheumatoid arthritis.
Fungal pathogens were detected in sputum samples of 51 people (19.8%), and bacteria in 22 (8.5%), with the most common pathogens being the fungus A. fumigatus and the bacteria Pseudomonas aeruginosa.
The investigators determined that TB heightened the risk for A. fumigatus sensitization, and that the duration of symptoms could predict the occurrence of chronic infection.
Symptoms tended to last longer in the idiopathic and “other” bronchiectasis cases, compared to those of TB, corresponding to more cases of chronic infection.
Fungal infections overall were more common among TB patients, and bacteria most often found in the sputum of those without TB. Accordingly, the simultaneous appearance of chronic infection by A. fumigatus and sensitization to the fungus was significantly higher in the TB group relative to the other patient groups.
Overall, “we found a high prevalence of Aspergillus sensitization and chronic Aspergillus infection in subjects with non-CF bronchiectasis,” the researchers wrote, adding that the cause of bronchiectasis influenced both sensitization and infection.
They suggested close monitoring of patients with non-CF bronchiectasis, due to a risk of developing other Aspergillus-related disorders. These include allergic bronchopulmonary aspergillosis — caused by an allergic reaction to Aspergillus — and chronic pulmonary aspergillosis, an uncommon but long-term lung infection.
Despite European guidelines for bronchiectasis that recommend evaluating Aspergillus sensitization during an initial visit, past studies estimate that this happens in more than 60% of patients, the research team noted.
“In addition to Aspergillus sensitization,” they added, ” investigations for chronic Aspergillus infection should be routinely performed at diagnosis and during follow-up.”