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Purpose: The extent of the survival benefit of augmentation therapy for alpha-1 antitrypsin deficiency (AATD) in individuals with advanced COPD is difficult to define. We performed a retrospective analysis using all available data from the observational registry of individuals with severe deficiency of alpha-1 antitrypsin (AAT) conducted by the NHLBI investigators., Patients and Methods: Individuals (N=1129) with severe deficiency of AAT were evaluated for mortality using all data sources and stratified by 10% increments of baseline forced expiratory volume in 1 second (FEV1) percent predicted and by augmentation therapy status (ever receiving versus never receiving). Kaplan-Meier survival curves were constructed for each of the deciles comparing survival in treated vs non-treated groups. A multivariable model was performed to define the correlates of survival in individuals with FEV1 <30% predicted., Results: Amongst all subjects, augmentation was associated with improved survival (p<0.0001). Among the individuals ever receiving augmentation therapy, survival was better than for those not receiving augmentation at all 10% increments of FEV1% predicted from 10% to 60% (P values <0.05 in all deciles). In subgroups of participants with hyperinflation defined as residual volume (RV)>120% predicted and in subgroups of participants with reduced diffusing capacity for carbon monoxide (DLCO) <70% predicted, there was significantly better survival for those ever receiving augmentation therapy than for those who never received augmentation (p<0.001). A multivariable analysis showed that mortality benefit is influenced by age, DLCO % predicted, and augmentation therapy., Conclusion: There is a survival benefit from augmentation therapy in AATD between FEV1 values in the 10-60% predicted range. Screening and treatment of AATD patients should therefore not be limited by the severity of illness as defined by FEV1., Competing Interests: TB reports grants with Grifols, outside the submitted work. CS is employed in part by AlphaNet, a disease management company for Alpha-1 antitrypsin deficiency. He reports grants from Adverum, Arrowhead, CSL Behring, Grifols, MatRx, Takeda, and Vertex. He has received personal fees from CSL Behring, Dicerna, and Vertex, all outside the submitted work. FR reports grants and personal fees, from Grifols, and Takeda outside the submitted work. The authors report no other conflicts of interest in this work., (© 2020 Rahaghi et al.)

Alpha-1 antitrypsin deficiency (AATD) is a common hereditary disorder caused by mutations in the SERPINA1 gene, which encodes alpha-1 antitrypsin (AAT; also known as alpha 1-proteinase inhibitor, A 1 -PI). An important function of A 1 -PI in the lung is to inhibit neutrophil elastase, one of various proteolytic enzymes released by activated neutrophils during inflammation. Absence or deficiency of A 1 -PI leads to an imbalance between elastase and anti-elastase activity, which results in progressive, irreversible destruction of lung tissue, and ultimately the development of chronic obstructive pulmonary disease with early-onset emphysema. AATD is under-diagnosed, patients can experience long delays before obtaining an accurate diagnosis, and the consequences of delayed diagnosis or misdiagnosis can be severe. Currently, A 1 -PI therapy is the only available treatment that addresses disease etiology in patients with AATD; however, demonstrating clinical efficacy of A 1 -PI therapy is challenging. In order to show therapeutic efficacy with traditional endpoints such as forced expiratory volume in one second and mortality, large sample sizes and longer duration trials are required. However, AATD is a rare, slow progressive disease, which can take decades to manifest clinically and recruiting sufficient numbers of patients into prolonged placebo-controlled trials remains a significant obstacle. Despite this, the Randomized, placebo-controlled trial of augmentation therapy in Alpha 1-Proteinase Inhibitor Deficiency (RAPID) and RAPID Extension trial, the largest clinical program completed to date, utilized quantitative chest computed tomography as a sensitive and specific measure of the extent of emphysema. Findings from the RAPID/RAPID Extension program definitively confirmed the benefits of A 1 -PI therapy in slowing disease progression and provided evidence of a disease-modifying effect of A 1 -PI therapy in patients with AATD. These findings suggest that the early introduction of treatment in patients with severe emphysema-related AATD may delay the time to death, lung transplantation or crippling respiratory complaints. In addition, there is now limited evidence that A 1 -PI therapy provides a gain of more than five life-years, supporting previous observations based on registry data. With the clinical efficacy of A 1 -PI therapy now demonstrated, further studies are required to assess long-term outcomes.

Introduction: Alpha-1 antitrypsin deficiency (AATD) is a genetic disease that may be manifested by chronic obstructive pulmonary disease. Despite professional society guidelines that recommend broad testing of at-risk individuals, fewer than 10% of affected individuals have been identified. The goals of this study were to estimate the frequency of abnormal AAT genotypes among patients found to have fixed airflow obstruction and to assess the feasibility of having Pulmonary Function Laboratory personnel administer the study., Methods: Nineteen medical centers in the United States participated in the study. Eligible patients (> GOLD II, FEV(1)/FVC ratio < 0.7, with post-bronchodilator FEV(1)<80% predicted) were offered testing for AATD by the Pulmonary Function Laboratory personnel at the time of pulmonary function testing., Results: A total of 3,457 patients were tested, of whom 3152 were eligible. Deficient patients (ZZ, SZ) constituted 0.63% of subjects, while 10.88% were carriers (MS, MZ). Neither demographic (except African-American race) nor post-bronchodilator pulmonary function variables (FEV(1), FVC, FEV(1)/FVC ratio, TLC, and FEV(1)/FVC) allowed us to predict AAT heterozygote or deficiency status., Conclusions: The prevalence of AATD among patients undergoing pulmonary function tests with fixed airflow obstruction was 0.63%. Pulmonary Function Laboratory personnel effectively conducted the study.