Immunological and homeostatic pathways of alpha -1 antitrypsin: a new therapeutic potential.

α -1 antitrypsin (A1AT) is a 52 kDa acute-phase glycoprotein belonging to the serine protease inhibitor superfamily (SERPIN). It is primarily synthesized by hepatocytes and to a lesser extent by monocytes, macrophages, intestinal epithelial cells, and bronchial epithelial cells. A1AT is encoded by SERPINA1 locus, also known as PI locus, highly polymorphic with at least 100 allelic variants described and responsible for different A1AT serum levels and function. A1AT inhibits a variety of serine proteinases, but its main target is represented by Neutrophil Elastase (NE). However, recent attention has been directed towards its immune-regulatory and homeostatic activities. A1AT exerts immune-regulatory effects on different cell types involved in innate and adaptive immunity. Additionally, it plays a role in metal and lipid metabolism, contributing to homeostasis. An adequate comprehension of these mechanisms could support the use of A1AT augmentation therapy in many disorders characterized by a chronic immune response. The aim of this review is to provide an up-to-date understanding of the molecular mechanisms and regulatory pathways responsible for immune-regulatory and homeostatic activities of A1AT. This knowledge aims to support the use of A1AT in therapeutic applications. Furthermore, the review summarizes the current state of knowledge regarding the application of A1AT in clinical and laboratory settings human and animal models.

Alpha-1 Antitrypsin Augmentation Therapy in Chronic Pancreatitis Patients Undergoing Total Pancreatectomy and Islet Autotransplantation: A Randomized, Controlled Study.

Stress-induced islet graft loss during the peri-transplantation period reduces the efficacy of islet transplantation. In this prospective, randomized, double-blind clinical trial, we evaluated the safety and efficacy of 60 mg/kg human alpha-1 antitrypsin (AAT) or placebo infusion weekly for four doses beginning before surgery in chronic pancreatitis (CP) patients undergoing total pancreatectomy and islet autotransplantation (TP-IAT). Subjects were followed for 12 months post-TP-IAT. The dose of AAT was safe, as there was no difference in the types and severity of adverse events in participants from both groups. There were some biochemical signals of treatment effect with a higher oxygen consumption rate in AAT islets before transplantation and a lower serum C-peptide (an indicator of islet death) in the AAT group at 15 min after islet infusion. Findings per the statistical analysis plan using a modified intention to treat analysis showed no difference in the C-peptide area under the curve (AUC) following a mixed meal tolerance test at 12 months post-TP-IAT. There was no difference in the secondary and exploratory outcomes. Although AAT therapy did not show improvement in C-peptide AUC in this study, AAT therapy is safe in CP patients and there are experiences gained on optimal clinical trial design in this challenging disease.

Evaluation of body weight-based dosing, alternative dosing regimens, and treatment interruptions for α1-proteinase inhibitors and implications on biochemical efficacy in patients with α1-antitrypsin deficiency.

INTRODUCTION: The recommended standard dose for α1-proteinase inhibitor (A1PI) augmentation therapy is 60 mg/kg once-weekly (QW) intravenous (IV) infusions that aim to maintain systemic A1PI levels >11 µM, the biochemical efficacy threshold, in patients with α1-antitrypsin deficiency (AATD). However, this standard dose may not be optimal for all patients. Body weight-based dosing, alternative dosing regimens, and treatment interruption periods were evaluated using population pharmacokinetic (PopPK) modeling and simulations. METHODS: A nonlinear mixed-effects PopPK model with covariate effects was developed using data from 3 clinical studies investigating 60 mg/kg QW IV A1PI infusions in patients with AATD (n = 65) to evaluate A1PI pharmacokinetic (PK) characteristics. Model-based simulations were conducted for predefined body weight categories, alternative dosing regimens (60-180 mg/kg QW or once every 2 weeks [Q2W]), and treatment interruption periods ranging from 3 to 14 days. RESULTS: A1PI PK characteristics were well described by a 2-compartment turnover model with zero-order input and linear elimination. Body weight was a statistically significant determinant of variability in central volume of distribution. Model-based simulations suggested that patients with a higher body weight may attain the 11 µM threshold quicker than patients with a lower body weight and that QW dosing was better at maintaining A1PI levels >11 µM, even when higher Q2W doses were administered. Missing a dose for as few as 3 days could result in A1PI levels <11 µM. DISCUSSION: Findings suggest that doses higher than 60 mg/kg administered QW might be more clinically beneficial in some patients with AATD, and that body weight should be considered in dose optimization.

Recommendations for the Implementation of the Self-Administration of Alpha-1 Antitrypsin.

Purpose: Administration of exogenous alpha-1 antitrypsin (AAT) is the only specific therapy for the management of pulmonary morbidity in patients with AAT deficiency. It requires weekly or biweekly intravenous infusions, which may impact patient independence and quality of life. Self-administration of AAT therapy is an alternative to reduce the burden for patients who require AAT therapy. We presented herein experts' recommendations for the implementation of a program for the self-administration of AAT. Methods: This project was conducted using a modified nominal group technique and was undertaken in two online meetings involving the participation of 25 experts: specialists in pulmonology (n=17), nurses (n=5) and hospital pharmacists (n=3). Results: The following issues were discussed, and several recommendations were agreed upon on the following topics: a) patient profile and clinical evaluation, establishing selection criteria that should include clinical as well as social criteria; b) role of health care professionals, suggested roles for specialists in pulmonology, nurses, and hospital pharmacists; c) training by the nurse, including recommendations before initiating the training and the content of the training sessions; and d) logistic issues and follow-up, adherence, and patient support. Conclusion: We expect this proposal to increase awareness of this therapeutic alternative and facilitate the implementation of self-administration programs, thus contributing to optimizing the patient experience with AAT therapy. Further research on the outcomes of these programs, especially from the patient perspective, will also help to improve their design and implementation.

Augmentation Therapy for Severe Alpha-1 Antitrypsin Deficiency Improves Survival and Is Decoupled from Spirometric Decline-A Multinational Registry Analysis.

Rationale: Intravenous plasma-purified alpha-1 antitrypsin (IV-AAT) has been used as therapy for alpha-1 antitrypsin deficiency (AATD) since 1987. Previous trials (RAPID and RAPID-OLE) demonstrated efficacy in preserving computed tomography of lung density but no effect on FEV1. This observational study evaluated 615 people with severe AATD from three countries with socialized health care (Ireland, Switzerland, and Austria), where access to standard medical care was equal but access to IV-AAT was not. Objectives: To assess the real-world longitudinal effects of IV-AAT. Methods: Pulmonary function and mortality data were utilized to perform longitudinal analyses on registry participants with severe AATD. Measurements and Main Results: IV-AAT confers a survival benefit in severe AATD (P < 0.001). We uncovered two distinct AATD phenotypes based on an initial respiratory diagnosis: lung index and non-lung index. Lung indexes demonstrated a more rapid FEV1 decline between the ages of 20 and 50 and subsequently entered a plateau phase of minimal decline from 50 onward. Consequentially, IV-AAT had no effect on FEV1 decline, except in patients with a Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 2 lung index. Conclusions: This real-world study demonstrates a survival advantage from IV-AAT. This improved survival is largely decoupled from FEV1 decline. The observation that patients with severe AATD fall into two major phenotypes has implications for clinical trial design where FEV1 is a primary endpoint. Recruits into trials are typically older lung indexes entering the plateau phase and, therefore, unlikely to show spirometric benefits. IV-AAT attenuates spirometric decline in lung indexes in GOLD stage 2, a spirometric group commonly outside current IV-AAT commencement recommendations.

Selective and sensitive measurement of human neutrophil elastase in clinical samples based on a novel assay principle for protease activity measurement.

Imbalances between proteases and protease inhibitors have been associated with several pathological conditions including emphysema as seen in α1-antitrypsin deficiency. For this pathological condition, unimpeded neutrophil elastase activity has been ascribed a pivotal role in the destruction of lung tissue and thus in disease progression. Therefore, low, or non-quantifiable neutrophil elastase (NE) activity levels determined in bronchoalveolar lavage solutions indicate the success of α1-antitrypsin (AAT) augmentation therapy as NE activity will be erased. To overcome the known limitations of available elastase activity assays regarding sensitivity and selectivity, we developed a new elastase activity assay, which fundamentally relies on the highly specific complex formation between AAT and active elastase. Plate-bound AAT captured active elastase from the sample undergoing complex formation, followed by the immunological detection of human NE. This assay principle facilitated the measurement of low pM amounts of active human NE. The data of the assay performance check demonstrated adequate accuracy and precision profiles meeting currently accepted best practices for this activity assay, which can be classified as a ligand-binding assay. Furthermore, spike-recovery studies at low human NE levels, carried out for three human bronchoalveolar samples, resulted in recoveries within the 100 ± 20% range, while good linearity and parallelism of the samples' dilution-response curves was observed. Altogether, complemented by the data of selectivity and robustness studies and the accuracy and precision profile obtained in buffer, this newly developed human NE activity assay was demonstrated to perform accurately and precisely in clinically relevant samples.

Alpha-1 antitrypsin deficiency: current therapy and emerging targets.

INTRODUCTION: Alpha1 antitrypsin deficiency (AATD), a common hereditary disorder affecting mainly lungs, liver and skin has been the focus of some of the most exciting therapeutic approaches in medicine in the past 5 years. In this review, we discuss the therapies presently available for the different manifestations of AATD and new therapies in the pipeline. AREAS COVERED: We review therapeutic options for the individual lung, liver and skin manifestations of AATD along with approaches which aim to treat all three. Along with this renewed interest in treating AATD come challenges. How is AAT best delivered to the lung? What is the desired level of AAT in the circulation and lungs which therapeutics should aim to provide? Will treating the liver disease increase the potential for lung disease? Are there treatments to target the underlying genetic defect with the potential to prevent all aspects of AATDrelated disease? EXPERT OPINION: With a relatively small population able to participate in clinical studies, increased awareness and diagnosis of AATD is urgently needed. Better, more sensitive clinical parameters will assist in the generation of acceptable and robust evidence of therapeutic effect for current and emerging treatments.

Gene therapy for alpha-1 antitrypsin deficiency: an update.

INTRODUCTION: Altering the human genetic code has been explored since the early 1990s as a definitive answer for the treatment of monogenic and acquired diseases which do not respond to conventional therapies. In Alpha-1 antitrypsin deficiency (AATD) the proper synthesis and secretion of alpha-1 antitrypsin (AAT) protein is impaired, leading to its toxic hepatic accumulation along with its pulmonary insufficiency, which is associated with parenchymal proteolytic destruction. Because AATD is caused by mutations in a single gene whose correction alone would normalize the mutant phenotype, it has become a popular target for both augmentation gene therapy and gene editing. Although gene therapy products are already a reality for the treatment of some pathologies, such as inherited retinal dystrophy and spinal muscular atrophy, AATD-related pulmonary and, especially, liver diseases still lack effective therapeutic options. AREAS COVERED: Here, we review the course, challenges, and achievements of AATD gene therapy as well as update on new strategies being developed. EXPERT OPINION: Reaching safe and clinically effective expression of the AAT is currently the greatest challenge for AATD gene therapy. The improvement and emergence of technologies that use gene introduction, silencing and correction hold promise for the treatment of AATD.

Mice inflammatory responses to inhaled aerosolized LPS: effects of various forms of human alpha1-antitrypsin.

Rodent models of lipopolysaccharide (LPS)-induced pulmonary inflammation are used for anti-inflammatory drug testing. We aimed to characterize mice responses to aerosolized LPS alone or with intraperitoneal (i.p.) delivery of alpha1-antitrypsin (AAT). Balb/c mice were exposed to clean air or aerosolized LPS (0.21 mg/mL) for 10 min per day, for 3 d. One hour after each challenge, animals were treated i.p. with saline or with (4 mg/kg body weight) one of the AAT preparations: native (AAT), oxidized (oxAAT), recombinant (recAAT), or peptide of AAT (C-36). Experiments were terminated 6 h after the last dose of AATs. Transcriptome data of mice lungs exposed to clean air versus LPS revealed 656 differentially expressed genes and 155 significant gene ontology terms, including neutrophil migration and toll-like receptor signaling pathways. Concordantly, mice inhaling LPS showed higher bronchoalveolar lavage fluid neutrophil counts and levels of myeloperoxidase, inducible nitric oxide synthase, IL-1ß, TNFα, KC, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Plasma inflammatory markers did not increase. After i.p. application of AATs, about 1% to 2% of proteins reached the lungs but, except for GM-CSF, none of the proteins significantly influenced inflammatory markers. All AATs and C-36 significantly inhibited LPS-induced GM-CSF release. Surprisingly, only oxAAT decreased the expression of several LPS-induced inflammatory genes, such as Cxcl3, Cd14, Il1b, Nfkb1, and Nfkb2, in lung tissues. According to lung transcriptome data, oxAAT mostly affected genes related to transcriptional regulation while native AAT or recAAT affected genes of inflammatory pathways. Hence, we present a feasible mice model of local lung inflammation induced via aerosolized LPS that can be useful for systemic drug testing.

Expert Perspectives on the Management of Alpha 1-Antitrypsin Deficiency.

Alpha 1-antitrypsin deficiency is an inherited autosomal codominant disorder, which predisposes patients to lung and/or liver disease. Even though it is considered rare, it is one of the most frequent genetic disorders worldwide, albeit remaining underdiagnosed. Several organizations and societies, including the Portuguese Society of Pulmonology have been elaborating guidelines and recommendations for the diagnosis and management of alpha 1-antitrypsin deficiency. Nevertheless, some important matters are yet to be included in those, mainly due to lack of robust scientific evidence, and continue to represent a point of discussion. This article reviews some important scientific publications and expresses the perspectives of a group of Portuguese experts regarding the management of alpha 1-antitrypsin deficiency, namely in terms of the pre and neonatal diagnosis, the impact of the COVID-19 pandemic, the validity of replacement therapy in lung transplant-receiving, and finally, alternative strategies of alpha 1-antitrypsin deficiency treatment to improve the patients' quality of life.

A deficiência de alfa 1-antitripsina é uma doença hereditária autossómica codominante que aumenta a predisposição para o desenvolvimento de doença pulmonar e/ou hepática. Esta doença, embora seja considerada rara, é um dos distúrbios genéticos mais comuns em todo o mundo. Contudo, atualmente ainda constitui uma doença subdiagnosticada. Várias organizações e sociedades, incluindo a Sociedade Portuguesa de Pneumologia, elaboraram recomendações e diretrizes para o diagnóstico e gestão da deficiência de alfa 1-antitripsina. Porém, estes documentos ainda não abordam alguns temas relevantes associados à gestão da deficiência de alfa 1-antitripsina, principalmente devido à falta de robustez na evidência científica, que continuam a representar um ponto de discussão entre a comunidade médica. Neste artigo é feita a revisão de publicações científicas relevantes acerca da deficiência de alfa 1-antitripsina, e são descritas as perspetivas de especialistas portugueses sobre a gestão da deficiência de alfa 1-antitripsina, nomeadamente ao nível do diagnóstico pré e neonatal, do impacto da pandemia COVID-19, da validação da terapêutica de aumento em doentes que receberam um transplante pulmonar e, por fim, estratégias alternativas para a melhoria do tratamento da deficiência de alfa 1-antitripsina de modo a promover a qualidade de vida dos doentes.

Effect of Aerosol Inhalation Combined With a Vibration Expectoration Machine on Sputum Volume, IGF-1, α1-AT and PDGF-B in Patients With Chronic Obstructive Pulmonary Emphysema.

Objective: Aerosol inhalation is commonly used in the treatment of chronic obstructive pulmonary emphysema (COPE). This study aimed to evaluate the effectiveness of aerosol inhalation combined with a vibration expectoration machine on COPE. Methods: From June 2019 to June 2020, 110 patients receiving COPE treatment in Linyi Central Hospital in China were included in this randomized controlled trial. All patients were randomly assigned into one of two groups using the random number table. A total of 55 patients were given aerosol inhalation combined with the use of a vibration expectoration machine in the study group, and 55 patients were given aerosol inhalation alone in the control group. The general data, clinical efficacy arterial blood gas index, pulmonary function index and serum levels of insulin-like growth factor 1 (IGF-1), alpha 1 antitrypsin (α1-AT) and platelet-derived growth factor-B (PDGF-B) were compared. Results: There was no difference in baseline characteristics between the 2 groups (P > .05). After treatment, the clinical efficacy in the study group was significantly higher than in the control group (96.36% vs 81.82%, respectively; P = .023), daily sputum production in the study group was significantly higher compared with the control group (80.92 ± 10.29 vs 58.63 ± 9.02 ml, respectively; P < .001) and hospitalization time was significantly reduced in the study group (11.87 ± 1.76 vs 17.62 ± 1.92 days, respectively; P < .001). In addition, the respiratory rate was significantly lower in the study group (17.43 ± 1.61 vs 22.08 ± 3.25, respectively; P < .001). Partial pressure of oxygen (P[O2]) was significantly higher (76.29 ± 7.34 vs 66.81 ± 7.93 mmHg, respectively; P < .001) and partial pressure of carbon dioxide (P[CO2]) was significantly lower (34.82 ± 6.02 vs 39.83 ± 6.01 mmHg respectively; P < .001) in the study group compared with the control group. In addition, forced expiratory volume in the first second (FEV1) (1.79 ± 0.36 vs 1.66 ± 0.28 L, respectively), forced vital capacity (FVC) (2.58 ± 0.28 vs 2.42 ± 0.11 L, respectively), forced expiratory volume in the first second as a percentage of the predicted value (FEV1%pred) (65.32 ± 4.03 vs 59.83 ± 4.76 L, respectively) and maximal mid-expiratory flow (MMEF) (1.51 ± 0.27% vs 1.36 ± 0.12%, respectively) were all significantly increased after treatment in the study group compared with the control group (all P < .001). The IGF-1 (104.92 ± 11.27 vs 137.83 ± 11.02 ng/mL, respectively) and PDGF-B (124.39 ± 14.29 vs 249.93 ± 33.49 ng/L, respectively) were significantly reduced in the study group after treatment (all P < .001). The α1-AT (2.82 ± 0.38 vs 2.17 ± 0.22 g/L, respectively) were significantly increased after treatment in the study group compared with the control group. Conclusion: Aerosol inhalation combined with the use of a vibration expectoration machine is worthy of clinical application, and can effectively improve outcomes in patients with COPE.

Alpha-1 antitrypsin: A novel biomarker and potential therapeutic approach for metabolic diseases.

It is well recognized that chronic low-grade systemic inflammation and autoimmunity contribute to the pathogenesis of metabolic syndrome, its associated diseases (e.g. type 2 diabetes, non-alcoholic fatty liver disease) and type 1 diabetes, respectively. Consequently, anti-inflammatory agents might play a role in managing these immune associated metabolic diseases. Alpha-1 antitrypsin (AAT), an endogenous acute phase protein being used for treatment of AAT deficiency (a rare genetic disease), has multiple functions including anti-inflammatory, immunomodulatory, anti-apoptosis and cytoprotective effects. In this review, we summarized basic and clinical studies that reported potential therapeutic role of AAT in metabolic syndrome associated diseases and type 1 diabetes. Studies that demonstrated AAT had the possibility to be used as a novel biomarker to predict these immune associated metabolic diseases were also included.

Alpha-1 antitrypsin in autoimmune diseases: Roles and therapeutic prospects.

Alpha-1 antitrypsin (A1AT) is a protease inhibitor in the serum. Its primary function is to inhibit the activity of a series of proteases, including proteinase 3, neutrophil elastase, metalloproteases, and cysteine-aspartate proteases. In addition, A1AT also has anti-inflammatory, anti-apoptotic, anti-oxidative stress, anti-viral, and anti-bacterial activities and plays essential roles in the regulation of tissue repair and lymphocyte differentiation and activation. The overactivation of the immune system characterizes the pathogenesis of autoimmune diseases. A1AT treatment shows beneficial effects on patients and animal models with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. This review summarizes the functions and therapeutic prospects of A1AT in autoimmune diseases.

Alpha-1 Asthma Overlap Syndrome: a Clinical Overview.

PURPOSE OF REVIEW: Alpha-1 antitrypsin deficiency (AATD) is one of the most common genetic diseases that is associated with severe complications and yet remains underdiagnosed. The pulmonary symptoms of both AATD and asthma include cough, excessive sputum production, dyspnea, and wheezing. These symptoms overlap significantly leading to difficulty distinguishing between these two conditions and suspicion that there may be an overlap syndrome. We aim to discuss the pathophysiology, clinical manifestations, and treatment of both alpha-1 antitrypsin and asthma and how they may overlap. RECENT FINDINGS: Recent literature suggests that there is an association between asthma and AATD. This association has been hypothesized to be secondary to an imbalance of elastase and anti-elastase leading to a pro-inflammatory state in patients with AATD. This review serves to overview the pathophysiology, clinical manifestations, and treatment of alpha-1 antitrypsin, asthma, and the increasingly recognized intersection of the two, AATD-asthma overlap syndrome.