Phenotypic Expression of Respiratory Diseases and Tailored Treatment in Patients with Intermediate Alpha-1 Antitrypsin Deficiency: Evidence from a Retrospective Analysis of a Selected Cohort of Patients.

Introduction

Alpha-1 antitrypsin deficiency (AATD) is a genetic condition caused by SERPINA1 variants with variable severity. Current international guidelines do not recommend augmentation therapy for intermediate AATD; nevertheless, some patients show clinically severe phenotypes in real-world practice. We aimed to evaluate, in an exploratory manner, the potential effects of augmentation therapy on exacerbations, quality of life, and lung function in this subgroup.

Methods

In this multicenter retrospective study, we included 27 heterozygous patients with intermediate AATD (serum AAT 50-110 mg/dL), Chronic Obstructive Pulmonary Disease (COPD), and/or emphysema. Clinical phenotypes included emphysema-predominant disease, COPD with frequent exacerbations, and overlap with bronchiectasis/asthma; HRCT patterns were recorded. We assessed the annual number of exacerbations (moderate: steroids/antibiotics; severe: hospitalization/including pneumothorax), St. George's Respiratory Questionnaire (SGRQ), and lung function before and after 12 months of therapy.

Results

Augmentation therapy was associated with a reduction in annual exacerbations from a median (IQR) of 2 (1.5-3) to 1 (0-1) (p < 0.0001) and an improvement in SGRQ total score (58.89 ± 16.83 to 48.34 ± 21.20; p = 0.0039). The mean SGRQ change exceeded the 4-point MCID for COPD. No significant changes were observed in spirometry or Diffusing Capacity of the Lung for Carbon Monoxide (DLCO).

Conclusions

These exploratory findings suggest that augmentation therapy may reduce exacerbations and improve quality of life in selected patients with intermediate AATD and COPD/emphysema. Given the retrospective design, small sample, and lack of a control group, the results should be interpreted as hypothesis-generating and warrant confirmation in prospective studies.