Long-term evolution of lung function in individuals with alpha-1 antitrypsin deficiency from the Spanish registry (REDAAT)

Background The clinical course of alpha-1 antitrypsin deficiency (AATD) is very heterogeneous. It is estimated that 60% of individuals with severe AATD (Pi*ZZ) develop emphysema. The main objective of this study was to describe the outcomes of long-term lung function in individuals with AATD-associated emphysema after at least 8 years of follow-up. Materials and methods We performed a retrospective analysis of longitudinal follow-up data of AATD PiZZ patients from the Spanish registry (AATD Spanish Registry [REDAAT]). The main follow-up outcome was the annual rate of decline in forced expiratory volume in 1 second (FEV1) calculated using the FEV1 values at baseline and in the last post-bronchodilator spirometry available. Results One hundred and twenty-two AATD PiZZ patients were analyzed. The median follow-up was 11 years (interquartile range =9-14). The mean FEV1 decline was 28 mL/year (SD=54), with a median of 33 mL/year. Tobacco consumption (β=19.8, p<0.001), previous pneumonia (β=27.8, p=0.026) and higher baseline FEV1% (β=0.798, p=0.016) were independently related to a faster FEV1 decline. Conclusion In this large cohort with a long follow-up, we observed a very variable decline of FEV1. However, the mean FEV1 decline was similar to that observed in large cohorts of smoking-related COPD. Tobacco consumption, previous pneumonia and better lung function at baseline were related to a faster decline in FEV1. These results highlight the importance of early diagnosis and effective treatment.