Bronchoscopic lung volume reduction using 1-way endobronchial valves (EBVs) may be a viable therapeutic option for patients with pulmonary emphysema and alpha-1 antitrypsin deficiency (AATD) or reduced alpha-1 antitrypsin (AAT) levels, according to a recent study published in Respiration.
The authors reported significant improvements in the study participants’ pulmonary function, exercise capacity, and quality of life.
For the purpose of this single-center, retrospective study, the researchers recruited 53 patients with emphysema and AATD or reduced AAT levels at the University Medical Center Groningen in the Netherlands between 2013 and 2021. The first group of participants comprised patients with serum AAT levels below 0.6 g/L or a confirmed ZZ phenotype (AATD group), and the second group included patients with possible or mild AATD based on reduced serum levels of AAT between 0.6 and 1 g/L.
The participants’ baseline and 6-month follow-up assessment included a high-resolution chest computed tomography (CT) scan and quantitative CT analysis, pulmonary function measurement, the 6-minute walking distance test, and St. George’s respiratory questionnaire. All patients underwent EBV treatment of the target lobe as determined by quantitative CT under general anesthesia.
According to the published results, all response variables significantly improved after treatment. The study authors noted median increases in forced expiratory volume in 1 second of 105 mL (12% relative) and 280 mL (31% relative) in the AATD and reduced AAT groups, respectively. Moreover, 6-minute walking distance test results increased by 62 min and 52 min and St. George’s respiratory questionnaire scores decreased by 12.5 patients and 18.7 patients, respectively.
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The safety profile of the treatment was regarded as acceptable in this study. Pneumothorax was recorded in 3 patients (10%) in the AATD group and 3 patients (13%) in the reduced AAT group, and no patients died.
“Successful treatment of AATD patients is very relevant since no other lung function-improving therapies are available at this moment, and lung transplantation is preferably postponed until the sixth decade of age,” Everaerts and colleagues noted. “Burden of this disease for patients, caregivers, and healthcare systems has recently been shown, and the latter seems higher compared to non-AATD [chronic obstructive pulmonary disease] patients.”
EBV is established as a valid therapy option for patients with severe emphysema, yet those with AATD have been excluded from the majority of relevant clinical trials and are rarely considered candidates for this intervention.
Everaerts S, Hartman JE, Van Dijk M, Koster TD, Slebos DJ, Klooster K. Bronchoscopic lung volume reduction in patients with emphysema due to alpha-1 antitrypsin deficiency. Respiration. Published online December 22, 2022. doi:10.1159/000528182