Supplementary Material for: Predicting exacerbations in α1-antitrypsin deficiency using clinical and pulmonary function tests: Portuguese EARCO registry

Introduction: Exacerbations are common in individuals with alpha-1-antitrypsin deficiency (AATD) related lung disease. This study intended to identify independent predictive factors for exacerbations in AATD using the Portuguese European Alpha-1 Research Collaboration (EARCO) registry.

Methods: This study includes patients from the Portuguese EARCO registry, a prospective multicentre cohort (NCT04180319). From October 2020 to April 2023 this registry enrolled 137 patients, 14 of whom were excluded for analysis for either missing 12 months of follow-up or baseline pulmonary function.

Results: Among the 123 AATD patients, 27 (22.0%) had at least one exacerbation in the last 12 months of follow-up. Patients with Pi*ZZ phenotype were three times more likely than the rest of the population to experience any exacerbation (32.7% vs 14.1%, p=0.014; OR 3.0). BODE index was significantly higher in exacerbators than in non-exacerbators (3.9±2.4 vs 1.3±1.2; p<0.001), including on multivariate analysis (p=0.002). Similar results were found for BODEx (multivariate p<0.001). DLCO was the only functional parameter independently associated with exacerbations (p=0.024).

Conclusions: DLCO, BODE and BODEx were independent predictors of exacerbations at 12 months in AATD patients. Understanding these risk factors can aid decision-making on AATD-related lung disease management and improve patient outcomes.