Alpha-1 Antitrypsin Deficiency Patients Research Articles

Technoeconomic Analysis of Intensified PEGylated Biopharmaceutical Recombinant Protein Production: Alpha Antitrypsin as a Model Case

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by the insufficient production of the AAT protein. Due to availability limitations, not all AATD patients receive protein therapy treatment. In this study, the technoeconomic analysis of different processes (conventional and intensified) producing 200 kg/year of PEGylated recombinant AAT (PEG-AAT) using a Chinese hamster ovary cell line was investigated. All bioprocesses consist of upstream, downstream, and PEGylation sections. A base-case model (process A) of the conventional fed-batch production bioreactor was developed using SuperPro Designer software (Version 13) to evaluate the economic feasibility of the process. The cost of goods (COG) was estimated to be approximately USD 387.6/g. Furthermore, an intensified process (B) was modeled and evaluated to reduce the COG. Process intensification was implemented in the process (N-1 perfusion bioreactor). The specific operating COG for process B was found to be 10% less than that of process A. Scenario analysis was performed to assess the impact of process capacity (100–1000 kg/year) and cell-specific productivity (30–90 pg/cell/day). With an increase in process capacity, the specific operating COG was reduced for all processes. Increasing cell-specific productivity decreases the specific operating COG at different rates for each process, depending on the titer level. Future investigations into the PEGylation section are required since it has the highest COG of all the sections.

Predicting Exacerbations in Alpha-1 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 multicenter 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.

Pulmonary Rehabilitation for Chronic Obstructive Pulmonary Disease Patients with Underlying Alpha-1 Antitrypsin Deficiency: A Systematic Review and Practical Recommendations.

Alpha-1 antitrypsin deficiency (AATD) is an often-overlooked genetic condition that makes individuals susceptible to early onset of chronic obstructive pulmonary disease (COPD). The established benefits of exercise-based pulmonary rehabilitation (PR) for usual COPD patients are unclear for those with underlying AATD, especially given potentially differing muscle adaptations to exercise. This review seeks to compare PR outcomes between AATD and usual COPD patients and to consolidate current knowledge on exercise intervention outcomes for the AATD population. A thorough search of 4 databases (Ovid, Medline, CINAHL, CENTRAL) was conducted based on 3 search concepts: (1) alpha-1 antitrypsin deficiency, (2) pulmonary rehabilitation OR exercise, and (3) muscle morphology. A dual review process and quality assessment were independently implemented throughout all stages of the review. Four studies highlighted modest exercise capacity and quality of life in AATD patients undergoing PR. However, one study reported unique muscle and mitochondrial responses compared to usual COPD patients. Additionally, a moderate exercise session did not alter pro-inflammatory cytokine levels in AATD patients, despite higher levels of tumor necrosis factor-α levels in muscle biopsies compared to usual COPD patients. The current literature base insufficiently addresses the efficacy of PR on AATD, with indications that exercise adaptation may deviate from that of usual COPD patients. Further research is needed to optimize PR, particularly in identifying the most suitable exercise intensity, and delivery setting, and addressing specific educational needs for individuals with AATD.

Lipoproteins in Negative Feedback with Alpha-1 Antitrypsin.

Alpha-1 antitrypsin deficiency patients (AATD) have lower risk of myocardial infarction, a cardiovascular disease that is related to increased remnant cholesterol levels, but not to low-density lipoprotein (LDL) levels. However, when AAT is knocked out in mice (AAT-KO), inflammatory-related, cholesterol metabolism-related, and lipid metabolism-related gene expression in mouse liver was increased, and these data support previous evidence from clinic patients and from a small clinical trial that AAT is in negative feedback regulation with LDL. Herein is a brief summary to examine the roles of AAT in these overlapping pathways.

Nine controversial questions about augmentation therapy for alpha-1 antitrypsin deficiency: a viewpoint.

Augmentation therapy with intravenous alpha-1 antitrypsin is the only specific treatment for alpha-1 antitrypsin deficiency (AATD)-associated emphysema. This treatment has been available and remained basically unchanged for more than 35 years, but many questions persist regarding its indications, regimen of administration and efficacy. Because AATD is a rare disease, it has not been possible to conduct randomised, placebo-controlled trials that are adequately powered for the usual outcomes analysed in non-AATD-related COPD, such as lung function decline, exacerbations, symptoms or quality of life. New outcomes such as lung densitometry measured by computed tomography are more sensitive for identifying emphysema progression but are not widely accepted by regulatory agencies. In addition, clinical manifestations, severity and the natural history of lung disease associated with AATD are very heterogeneous, which means that individual prediction of prognosis is challenging. Therefore, the indication for augmentation is sometimes a dilemma between initiating treatment in individuals who may not develop significant lung disease or in whom disease will not progress and delaying it in patients who will otherwise rapidly and irreversibly progress.Other areas of debate are the possible indication for augmentation in patients with severe AATD and respiratory diseases other than emphysema, such as bronchiectasis or asthma, and the use of therapy after lung transplant in AATD patients. All these uncertainties imply that the indication for treatment must be personalised in expert reference centres after in-depth discussion of the pros and cons of augmentation with the patient.

Predicting Lung Function Using Biomarkers in Alpha-1 Antitrypsin Deficiency.

Lung disease progression in alpha-1 antitrypsin deficiency (AATD) is heterogenous and manifests in different ways. Blood biomarkers are an attractive method of monitoring diseases as they are easy to obtain and repeatable. In non-AATD COPD, blood biomarker panels have predicted disease severity, progression, and mortality. We measured a panel of seven serum biomarkers in 200 AATD patients and compared levels between those with COPD and those without. We assessed whether biomarkers were associated with baseline lung function parameters (FEV1 and TLco) or absolute change in these parameters. In total, 111 patients with a severely deficient genotype of AATD (PiZZ) and COPD were included in the analyses. Pearson's correlation coefficient was measured for biomarker correlations and models were compared using ANOVA. CRP and CCL18 were significantly higher in the serum of AATD COPD versus AATD with no COPD. Biomarkers were not predictive of cross-sectional lung function measurements, however, CC16 was significantly associated with an absolute change in TLco (p = 0.018). An addition of biomarkers to the predictive model for TLco added significant value over covariates alone (R2 0.13 vs. 0.02, p = 0.028). Our findings suggest that CC16 is predictive of emphysema progression in AATD COPD. Proteomics data may reveal alternative candidate biomarkers and further work should include the use of longitudinal biomarker measurements.

Estimating the Prevalence of AATD Patients in the UK to Identify Underdiagnosis and Determine the Eligibility for Potential Augmentation Therapy.

Alpha 1 antitrypsin deficiency (AATD) is a genetic risk factor for chronic obstructive pulmonary disease (COPD). Whilst testing for the condition is relatively simple, there is a disconnect in published literature between genetic epidemiology and numbers of patients known to specialists. This makes planning services for patients difficult. We aimed to estimate the number of patients likely to have lung disease eligible for specific AATD therapy within the UK. The THIN database was used to determine the prevalence of AATD and symptomatic COPD. This, and published rates of AATD were used to extrapolate THIN data to the population size of the UK to give an indicative population size for symptomatic AATD patients who have lung disease. The Birmingham AATD registry was used to describe age at diagnosis, rate of lung disease and symptomatic lung disease for patients with PiZZ (or equivalent) AATD, together with the time from symptom onset to diagnosis, in order to aid interpretation of the THIN data and improve modeling. THIN data showed COPD prevalence of 3%, and AATD prevalence of 0.005-0.2%, depending on how stringently AATD diagnostic codes were applied. The majority of Birmingham AATD patients were diagnosed between the ages 46-55, whilst patients recorded in THIN tended to be older. The rate of COPD was similar in the THIN and Birmingham patients diagnosed with AATD. Modelling to the size of the UK demonstrated a likely symptomatic AATD population of between 3016 and 9866 people. AATD is likely to be under-diagnosed in the UK. Based on projected patient numbers an expansion to specialist services is desirable, in particular if specific therapy for AATD such as augmentation were to be introduced to the healthcare system.

Hypoxia Enhances Oxidative Stress in Neutrophils from ZZ Alpha-1 Antitrypsin Deficiency Patients.

Alpha-1 antitrypsin deficiency (AATD) is a neutrophilic inflammatory disorder that may result in local hypoxia, reactive oxygen and nitrogen species (ROS/RNS) production, and increased damage in adjacent tissues. This study aims to determine the impact of hypoxia on neutrophil oxidative stress profile in AATD patients. Neutrophils were isolated from AATD patients and control volunteers and exposed to hypoxia (1% O2 for 4 h), ROS/RNS, mitochondrial parameters, and non-enzymatic antioxidant defenses measured by flow cytometry. The expression of enzymatic antioxidant defenses was determined by qRT-PCR. Our results indicate that ZZ-AATD neutrophils produce higher amounts of hydrogen peroxide, peroxynitrite, and nitric oxide and decreased levels of the antioxidant enzymes catalase, superoxide dismutase, and glutathione reductase. Likewise, our results show a decrease in mitochondrial membrane potential, indicating that this organelle could be involved in the production of the reactive species observed. No decrease in glutathione and thiol levels were observed. The accumulation of substances with high oxidative capacity would explain the greater oxidative damage observed in proteins and lipids. In conclusion, our results indicate that, compared to MM control individuals, ZZ-AATD neutrophils show increased ROS/RNS production under hypoxic conditions opening a new rationale for using antioxidant therapies to treat the disease.

Cleaning up alpha-1 antitrypsin deficiency related liver disease.

Alpha-1 antitrypsin deficiency (AATD) is one of the most common genetic disorders arising due to mutations in alpha-1 antitrypsin (AAT) gene affecting primarily the lung and the liver. This review summarizes the pathophysiology and clinical manifestation of different AATD genotypes and discusses the recent therapeutic developments. The focus is on the severe, rare homozygous Pi∗ZZ and the common heterozygous Pi∗MZ genotype. Pi∗ZZ individuals harbor an up to 20 times higher risk of liver fibrosis and cirrhosis than noncarriers and liver transplantation is currently the only available therapeutic option. AATD constitutes a proteotoxic disorder arising from hepatic AAT accumulation and the currently most promising data come from a phase 2, open-label trial of fazirsiran, a hepatocyte-targeted siRNA. Pi∗MZ subjects display an increased risk of advanced liver disease and at the latter stage, a faster deterioration than individuals without AAT mutation. Although the fazirsiran data offer a glimpse of hope to AATD patients, a consensus on appropriate study endpoint, a careful patient selection as well as monitoring of long-term safety will be essential for an approval.

SERPINA1 and More? A Putative Genetic Contributor to Pulmonary Dysfunction in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is a common inherited disorder associated with an increased risk of pulmonary disease. Its clinical presentation, including the nature and severity of organ involvement, is highly variable and unpredictable and is not as strongly linked to genotype and environmental exposure (e.g., smoking history) as might be expected. Significant differences were observed within matched populations of severe AATD patients regarding risk of complications, age at onset, and disease course, including the dynamics of lung function decline. Genetic factors are among the putative modifiers contributing to the clinical variability in AATD, yet their role remains elusive. Here, we review and summarise our current understanding of epigenetic and genetic modifiers of pulmonary dysfunction in subjects with AATD.

COVID-19’s impact on care practice for alpha-1-antitrypsin deficiency patients

BackgroundPatients with alpha-1 antitrypsin deficiency (AATD), commonly categorized as a rare disease, have been affected by the changes in healthcare management brought about by COVID-19. This study’s aim was to identify the changes that have taken place in AATD patient care as a result of the COVID-19 pandemic in Spain and to propose experts’ recommendations aimed at ensuring humanized and quality care for people with AATD in the post-pandemic situation.MethodsA qualitative descriptive case study with a holistic single-case design was conducted, using focus groups with experts in AATD clinical management, including 15 health professionals with ties to the Spanish health system (12 pneumologists and 2 hospital pharmacists from 11 different hospitals in Spain) and 1 patient representative.ResultsCOVID-19 has had a major impact on numerous aspects of AATD clinical patient management in Spain, including diagnostic, treatment, and follow-up phases. The experts concluded that there is a need to strengthen coordination between Primary Care and Hospital Care and improve the coordination processes across all the organizations and actors involved in the healthcare system. Regarding telemedicine and telecare, experts have concluded that it is necessary to promote this methodology and to develop protocols and training programs. Experts have recommended developing personalized and precision medicine, and patient participation in decision-making, promoting self-care and patient autonomy to optimize their healthcare and improve their quality of life. The possibility of monitoring and treating AATD patients from home has also been proposed by experts. Another result of the study was the recommendation of the need to ensure that plasma donations are made on a regular basis by a sufficient number of healthy individuals.ConclusionThe study advances knowledge by highlighting the challenges faced by health professionals and changes in AATD patient management in the context of the COVID-19 pandemic. It also proposes experts’ recommendations aimed at ensuring humanized and quality care for people with AATD in the post-pandemic situation. This work could serve as a reference study for physicians on their daily clinical practice with AATD patients and may also provide guidance on the changes to be put in place for the post-pandemic situation.

Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency.

Intravenous alpha-1 antitrypsin (AAT) augmentation therapy is the only specific treatment available for alpha-1 antitrypsin deficiency (AATD)-related lung disease. It is widely used worldwide but remains unavailable to patients with AATD in the United Kingdom. While randomized trials of augmentation therapy have demonstrated biochemical efficacy and lung tissue preservation using computed tomography (CT) densitometry, these studies were not adequately powered to demonstrate effectiveness in well-accepted clinical endpoints such as quality of life (QOL) or survival. We used large, prospectively followed AATD patient populations in the United States and United Kingdom to explore these important clinical endpoints. Our inclusion criterion was adults with severe AATD and associated lung disease. The treatment group was U.S. AATD patients receiving augmentation therapy for lung disease. The control group was augmentation therapy naïve AATD patients. Multivariable regression and survival analyses were used to assess QOL and mortality outcomes respectively. Mean annual deterioration of the St George's Respiratory Questionnaire total score was 1.43 points greater/year in the control group compared to those receiving augmentation therapy (95% confidence interval [CI] 0.47 to 2.39, p=0.003). At 7 years, median survival was 82.7% (95% CI 75.3 to 90.7) for the control group versus 87.8% (95% CI 82.8 to 93.2) in the augmentation group, p=0.66. There was significant heterogeneity between cohorts. A comparison of 2 highly characterized AATD cohorts was not able to reliably determine if AAT augmentation therapy improves QOL or mortality in patients with severe AATD-related lung disease. Alternative surrogate biomarkers of disease progression, such as CT lung density, may be a more pragmatic option.

“Idiopathic Pulmonary Fibrosis and Alpha 1 Antitrypsin Deficiency: A Case Report of a Patient Undergoing Lung Transplantation and Intravenous Augmentation Therapy

Idiopathic Pulmonary Fibrosis (IPF) is a chronic interstitial lung disease characterized by progressive lung scarring and the pathological hallmark of usual interstitial pneumonia (UIP). On the other hand, Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder predisposing individuals to lung and liver diseases. Despite its rarity in literature, the relationship between IPF and AATD remains unclear. While IPF often necessitates lung transplantation in advanced stages, traditional AATD management involves supportive therapy. However, the introduction of supplemental alpha1-antitrypsin (AAT) derived from pooled human plasma has shown promise in retarding lung function decline. Notably, post lung transplantation, the genetic basis of AATD-related lung disease persists, potentially exposing patients to disease recurrence. Here, we present a clinical case of a patient initially diagnosed with IPF who subsequently underwent double lung transplantation and was later diagnosed with AATD. This case study prompts inquiry into critical unresolved questions: the potential benefits of post-transplant augmentation therapy for AATD patients and the potential association between AATD and pulmonary fibrosis. The intricate interplay between these two conditions underscores the need for further investigation to enhance our understanding and improve patient outcomes

CASE STUDY OF CONCURRENT ALPHA-1 ANTITRYPSIN DEFICIENCY AND ASTHMA.

<h3>Introduction</h3> Asthma and alpha-1 antitrypsin deficiency (AATD) differ in pathogenesis but can present with similar clinical symptoms, such as dyspnea, wheezing and cough. The similarity of symptoms can often lead to delayed or missed diagnosis of AATD in patients with concurrent asthma. Our abstract focuses on the importance of assessing for AATD in those with fixed obstructive lung disease. <h3>Case Description</h3> Patient A is a 65-year-old male with a history of longstanding asthma, who exhibited rapid progressive decline in FEV1 on serial pulmonary function tests (PFTs). Subsequent workup revealed MZ genotype of alpha-1 antitrypsin deficiency. His symptoms were thought to be primarily asthma-related, given air trapping and bronchodilator reversibility on PFTs. Patient B is a 58-year-old male with known alpha-1 antitrypsin deficiency (ZZ genotype), although he was only mildly symptomatic. Increasing episodes of wheezing and decreasing FEV1 prompted FeNO testing, which supported superimposed asthma. <h3>Discussion</h3> Concurrent asthma and AATD can worsen pulmonary inflammation. Alpha-1 antitrypsin can have immunomodulatory effects on inflammatory cells and inactivate elastase, thus preserving lung function. Shared symptoms and vague screening guidelines for coincident asthma and AATD can often delay diagnosis in patients with both diseases, potentially worsening patient outcomes. In our patients, further testing was only prompted due to progressive clinical decline, which ideally could have been preempted. We hope that these cases will bring increased awareness to diagnostic and therapeutic challenges in patients with AATD and asthma.

Alpha-1 Antitrypsin Therapy Modifies Neutrophil Adhesion in Patients with Obstructive Lung Disease.

Alpha-1 antitrypsin deficiency (AATD) is characterized by neutrophil-dominated inflammation resulting in emphysema. The cholesterol-rich neutrophil outer plasma membrane plays a central role in adhesion and subsequent transmigration to underlying tissues. This study aimed to investigate mechanisms of increased neutrophil adhesion in AATD and whether alpha-1 antitrypsin (AAT) augmentation therapy abrogates this effect. Plasma and blood neutrophils were donated by healthy controls (n = 20), AATD (n = 30), and AATD patients after AAT augmentation therapy (n = 6). Neutrophil membrane protein expression was investigated using liquid chromatography-tandem mass spectrometry. The effect of once-weekly intravenous AAT augmentation therapy was assessed by calcium fluorometric, μ-calpain, and cell adhesion assays. Decreased neutrophil plasma membrane cholesterol content (P = 0.03), yet increased abundance of integrin α-M (fold change 1.91), integrin α-L (fold change 3.76), and cytoskeletal adaptor proteins including talin-1 (fold change 4.04) were detected on AATD neutrophil plasma membrane fractions. The described inflammatory induced structural changes were a result of a more than twofold increased cytosolic calcium concentration (P = 0.02), leading to significant calcium-dependent μ-calpain activity (3.5-fold change; P = 0.005), resulting in proteolysis of the membrane cholesterol trafficking protein caveolin-1. Treatment of AAT-deficient individuals with AAT augmentation therapy resulted in increased caveolin-1 and membrane cholesterol content (111.8 ± 15.5 vs. 64.18 ± 7.8 μg/2 × 107 cells before and after treatment, respectively; P = 0.02), with concurrent decreased neutrophil integrin expression and adhesion. Results demonstrate an auxiliary benefit of AAT augmentation therapy, evident by a decrease in circulating inflammation and controlled neutrophil adhesion.

Disease burden associated with alpha-1 antitrypsin deficiency: systematic and structured literature reviews.

Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disorder characterised by reduced levels of circulating alpha-1 antitrypsin and an increased risk of lung and liver disease. Recent reviews of AATD have focused on diagnosis, epidemiology and clinical management; comprehensive reviews examining disease burden are lacking. Therefore, we conducted literature reviews to investigate the AATD disease burden for patients, caregivers and healthcare systems. Embase, PubMed and Cochrane libraries were searched for AATD publications from database inception to June 2021, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Most published AATD studies were small and short in duration, with variations in populations, designs, measures and outcomes, complicating cross-study comparisons. AATD was associated with significant pulmonary and hepatic morbidity. COPD, emphysema and bronchiectasis were common lung morbidities, where smoking was a key risk factor. Fibrosis and steatosis were the most common liver complications reported in patients with a PiZ allele. Health status analyses suggested a poorer quality of life for AATD patients diagnosed with COPD versus those with non-AATD-associated COPD. The burden for caregivers included loss of personal time due to caring responsibilities, stress and anxiety. AATD was also associated with high direct medical costs and healthcare resource utilisation.

Leave no one behind: inclusion of alpha-1 antitrypsin deficiency patients in COVID-19 vaccine trials.

The coronavirus disease of 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, continues to present an unprecedented challenge worldwide. Emerging evidence suggests that α-1 antitrypsin (A1AT), a circulating protein with protective effects on the lung and other vital organs, plays a critical role in preventing SARS-CoV-2 infection and may be a promising therapeutic option for patients with COVID-19. A1AT deficiency (AATD) is characterized by dysfunctional or insufficient levels of A1AT. Recently, we have proposed that AATD patients are a vulnerable population for COVID-19. Patients with AATD may derive limited benefit from the current COVID-19 vaccines and continue to rely on conventional medical therapy and behavioral adaptations to mitigate the risk of infection. Unfortunately, this population has not been included in the COVID-19 vaccine clinical trials and studies have yet to characterize the safety, immunogenicity, and ultimately, the efficacy of COVID-19 vaccines for AATD patients. Re-evaluation of the COVID-19 vaccine safety and immunogenicity will further promote informed decision-making for vaccination in AATD individuals and contribute to reduce morbidity and mortality from COVID-19 infection.

Prevalence of Alpha-1 Antitrypsin Deficiency, Self-Reported Behavior Change, and Health Care Engagement Among Direct-to-Consumer Recipients of a Personalized Genetic Risk Report

Alpha-1 antitrypsin deficiency (AATD) is an autosomal co-dominant condition that predisposes to emphysema, cirrhosis, panniculitis, and vasculitis. Underrecognition has prompted efforts to enhance early detection and testing of at-risk individuals. Direct-to-consumer (DTC) genetic testing represents an additional method of detection. The study addressed three questions: (1) Does a DTC testing service identify previously undetected individuals with AATD? (2) What was the interval between initial AATD-related symptoms and initial diagnosis of AATD in such individuals? and (3) What was the behavioral impact of learning about a new diagnosis of AATD through a DTC test? In this cross-sectional study, 195,014 individuals responded to a survey within the 23andMe, Inc. research platform. Among 195,014 study participants, the allele frequency for the PI∗S and PI∗Z AATD variants was 21.6%(6.5%for PI∗Z and 15.1%for PI∗S); 0.63%were PI∗ZZ, half of whom reported having a physician confirm the diagnosis. Approximately 27%of those with physician-diagnosed AATD reported first becoming aware of AATD through the DTC test. Among those newly aware participants, the diagnostic delay interval was 22.3 years. Participants frequently shared their DTC test results with health care providers (HCPs) and the reported impact of learning a diagnosis of AATD was high. For example, 51.1%of PI∗ZZ individuals shared their DTC result with an HCP. The OR for PI∗ZZ smokers to report smoking reduction as a result of receiving the DTC result was 1.7 (95% CI= 1.4-2.2) compared with those without a Z allele and for reduced alcohol consumption this was 4.0 (95% CI= 2.6-5.9). In this largest available report on DTC testing for AATD, this test, in combination with clinical follow-up, can help to identify previously undiagnosed AATD patients. Moreover, receipt of the DTC AATD report was associated with positive behavior change, especially among those with risk variants.

Alpha-1 Antitrypsin Augmentation Inhibits Proteolysis of Neutrophil Membrane Voltage-Gated Proton Channel-1 in Alpha-1 Deficient Individuals.

Background and Objectives: Alpha-1 antitrypsin is a serine protease inhibitor that demonstrates an array of immunomodulatory functions. Individuals with the genetic condition of alpha-1 antitrypsin deficiency (AATD) are at increased risk of early onset emphysematous lung disease. This lung disease is partly driven by neutrophil mediated lung destruction in an environment of low AAT. As peripheral neutrophil hyper-responsiveness in AATD leads to excessive degranulation and increased migration to the airways, we examined the expression of the membrane voltage-gated proton channel-1 (HVCN1), which is integrally linked to neutrophil function. The objectives of this study were to evaluate altered HVCN1 in AATD neutrophils, serine protease-dependent degradation of HVCN1, and to investigate the ability of serum AAT to control HVCN1 expression. Materials and Methods: Circulating neutrophils were purified from AATD patients (n = 20), AATD patients receiving AAT augmentation therapy (n = 3) and healthy controls (n = 20). HVCN1 neutrophil expression was assessed by flow cytometry and Western blot analysis. Neutrophil membrane bound elastase was measured by fluorescence resonance energy transfer. Results: In this study we demonstrated that HVCN1 protein is under-expressed in AATD neutrophils (p = 0.02), suggesting a link between reduced HVCN1 expression and AAT deficiency. We have demonstrated that HVCN1 undergoes significant proteolytic degradation in activated neutrophils (p < 0.0001), primarily due to neutrophil elastase activity (p = 0.0004). In addition, the treatment of AATD individuals with AAT augmentation therapy increased neutrophil plasma membrane HVCN1 expression (p = 0.01). Conclusions: Our results demonstrate reduced levels of HVCN1 in peripheral blood neutrophils that may influence the neutrophil-dominated immune response in the AATD airways and highlights the role of antiprotease treatment and specifically AAT augmentation therapy in protecting neutrophil membrane expression of HVCN1.

Adenine base editing reduces misfolded protein accumulation and toxicity in alpha-1 antitrypsin deficient patient iPSC-hepatocytes

Alpha-1 antitrypsin deficiency (AATD) is most commonly caused by the Z mutation, a single-base substitution that leads to AAT protein misfolding and associated liver and lung disease. In this study, we apply adenine base editors to correct the Z mutation in patient induced pluripotent stem cells (iPSCs) and iPSC-derived hepatocytes (iHeps). We demonstrate that correction of the Z mutation in patient iPSCs reduces aberrant AAT accumulation and increases its secretion. Adenine base editing (ABE) of differentiated iHeps decreases ER stress in edited cells, as demonstrated by single-cell RNA sequencing. We find ABE to be highly efficient in iPSCs anddo not identify off-target genomic mutations by whole-genome sequencing. These results reveal the feasibility and utility of base editing to correct the Z mutation in AATD patient cells.