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α1-antitrypsin (AAT) deficiency is a common autosomal recessive hereditary disorder, with a high risk for the development of early-onset panacinar emphysema. AAT, produced primarily in the liver, functions to protect the lung from neutrophil protease; with AAT deficiency, unimpeded neutrophil proteases destroy the lung parenchyma. AAT is susceptible to oxidative damage resulting in an inability to inhibit its target proteases, neutrophil elastase, and cathepsin G. The major sites of oxidative modification on the AAT molecule are methionine residues 351 and 358. We have previously demonstrated that an engineered variant of AAT that resists oxidation by modifying both protein surface methionines (M351V and M358L) provides antiprotease protection, despite oxidative stress. In mice, intravenous delivery of the modified AAT(AVL) variant by AAV serotype 8, AAV8hAAT(AVL), primarily to the liver resulted in long-term expression of an AAT that resists oxidative inactivation. In this study, we evaluated the safety of intravenous administration of AAV8hAAT(AVL) in a dose-escalating, blinded, placebo-controlled toxicology study in wild-type mice. The study assessed organ histology and clinical pathology findings of mice, intravenously administered AAV8hAAT(AVL) at three doses (5.0 × 10 11 , 5.0 × 10 12 , and 5.0 × 10 13 genome copies [gc]/kg), compared to control mice injected intravenously with phosphate-buffered saline. As previously demonstrated, administration of AAV8hAAT(AVL) resulted in dose-dependent expression of high, potentially therapeutic, levels of serum human AAT protein that persist for at least 6 months. Antibodies against the AAV8 capsid were elicited as expected, but there was no antibody detected against the AAT(AVL) protein generated by the AAV8hAAT(AVL) vector. There was no morbidity or mortality observed in the study. The data demonstrate that intravenous administration of AAV8hAAT(AVL) is safe with no significant adverse effect attributed to AAV8hAAT(AVL) vector at any dose. This study demonstrates that AAV8hAAT(AVL) has a safety profile consistent with the requirements for proceeding to a clinical study.

Background: Alpha1-antitrypsin deficiency (AATD) is a genetic-based risk condition, mainly affecting the lungs and liver. Despite its wide distribution, it is largely underdiagnosed, thus being considered a rare disease, and is consequently managed in ad-hoc reference centers. Unfortunately, an easy-to-use algorithm for managing such a complex disease is still lacking., Methods: An expert consensus meeting was conducted among experts in the management of AATD to build a comprehensive algorithm, including diagnosis, monitoring, AAT therapy, rehabilitation and lung transplantation, and liver disease, that could serve as a guide for physicians and treating centers. A panel of AATD specialists evaluated the results of their work., Results: Diagnosis is the most delicate phase, and awareness about this condition should be raised among GPs. A set of recommendations has been written about the most suitable follow-up visits. Augmentation therapy with AAT may be useful to reduce the progression of emphysema and lung function decline in selected patients. Exercise capacity may be improved by pulmonary rehabilitation and, in selected cases, by lung volume reduction or lung transplantation. Support therapies are needed for those who develop liver disease, and, in selected cases, liver transplantation may be considered. Patients should be carefully educated about their lifestyle, including smoking cessation, body weight control, and reduced alcohol intake., Conclusions: The proposed algorithm obtained the endorsement of the Italian Society of Pneumology (SIP). However, further studies and additional clinical data are required to confirm the validity of these recommendations.

Alpha-1 antitrypsin deficiency (AATD) is the most common genetic cause and risk factor for chronic obstructive pulmonary disease, but the field lacks a large-animal model that allows for longitudinal assessment of pulmonary function. We hypothesized that ferrets would model human AATD-related lung and hepatic disease. AAT-knockout (AAT-KO) and PiZZ (E342K, the most common mutation in humans) ferrets were generated and compared with matched controls using custom-designed flexiVent modules to perform pulmonary function tests, quantitative computed tomography (QCT), bronchoalveolar lavage (BAL) proteomics, and alveolar morphometry. Complete loss of AAT (AAT-KO) led to increased pulmonary compliance and expiratory airflow limitation, consistent with obstructive lung disease. QCT and morphometry confirmed emphysema and airspace enlargement, respectively. Pathway analysis of BAL proteomics data revealed inflammatory lung disease and impaired cellular migration. The PiZ mutation resulted in altered AAT protein folding in the liver, hepatic injury, and reduced plasma concentrations of AAT, and PiZZ ferrets developed obstructive lung disease. In summary, AAT-KO and PiZZ ferrets model the progressive obstructive pulmonary disease seen in AAT-deficient patients and may serve as a platform for preclinical testing of therapeutics including gene therapy.

Inherited deficiency of the antiprotease alpha-1 antitrypsin (AAT) is associated with liver failure and early-onset emphysema. In mice, in vivo lentiviral transduction of alveolar macrophages (AMs) has been described to yield protective pulmonary AAT levels and ameliorate emphysema development. We here investigated the pulmonary transplantation of macrophages (PMT) transgenic for AAT as a potential therapy for AAT deficiency-associated lung pathology. Employing third-generation SIN-lentiviral vectors expressing the human AAT cDNA from the CAG or Cbx-EF1α promoter, we obtained high-level AAT secretion in a murine AM cell line as well as murine bone marrow-derived macrophages differentiated in vitro (AAT MΦ). Secreted AAT demonstrated a physiologic glycosylation pattern as well as elastase-inhibitory and anti-apoptotic properties. AAT MΦ preserved normal morphology, surface phenotype, and functionality. Furthermore, in vitro generated murine AAT MΦ successfully engrafted in AM-deficient Csf2rb -/- mice and converted into a CD11c + /Siglec-F + AM phenotype as detected in bronchoalveolar lavage fluid and homogenized lung tissue 2 months after PMT. Moreover, human AAT was detected in the lung epithelial lining fluid of transplanted animals. Efficient AAT expression and secretion were also demonstrated for human AAT MΦ, confirming the applicability of our vectors in human cells., (© 2021. The Author(s).)

Alpha-1 antitrypsin deficiency is an autosomal codominant genetic disease characterized by low levels of alpha-1 antitrypsin in the blood. Clinically, in young patients, it mainly manifests as emphysema, acute/chronic liver injury and liver cancer. The treatment methods include symptomatic treatment and alpha -1 antitrypsin supplementation. However, the existing treatment cannot prevent the liver fibrosis progression. At present, more than ten cases of the disease have been reported in China, but the understanding of this disease is still indecisive. Moreover, there exists no biotherapy drug for this disorder. This article introduces the research progress of hepatocyte transplantation treatment for this disorder.

Introduction: Alpha-1 antitrypsin (AAT) deficiency (AATD) is associated with early onset emphysema. The aim of this study was to investigate whether AAT binding to plasma constituents could regulate their activation, and in AATD, exploit this binding event to better understand the condition and uncover novel biomarkers of therapeutic efficacy., Methods: To isolate AAT linker proteins, plasma samples were separated by size exclusion chromatography, followed by co-immunoprecipitation. AAT binding proteins were identified by mass spectrometry. Complement turnover and activation was determined by ELISA measurement of C3, C3a and C3d levels in plasma of healthy controls (n=15), AATD (n=51), non-AATD patients with obstructive airway disease (n=10) and AATD patients post AAT augmentation therapy (n=5)., Results: Direct binding of complement C3 to AAT was identified in vivo and in vitro. Compared with healthy controls, a breakdown product of C3, C3d, was increased in AATD (0.04 µg/mL vs 1.96 µg/mL, p=0.0002), with a significant correlation between radiographic pulmonary emphysema and plasma levels of C3d (R 2 =0.37, p=0.001). In vivo, AAT augmentation therapy significantly reduced plasma levels of C3d in comparison to patients not receiving AAT therapy (0.15 µg/mL vs 2.18 µg/mL, respectively, p=0.001)., Discussion: Results highlight the immune-modulatory impact of AAT on the complement system, involving an important potential role for complement activation in disease pathogenesis in AATD. The association between plasma C3d levels and pulmonary disease severity, that decrease in response to AAT augmentation therapy, supports the exploration of C3d as a candidate biomarker of therapeutic efficacy in AATD., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Alpha-1 antitrypsin deficiency (AATD) is a rare and underdiagnosed genetic predisposition for COPD and emphysema and other conditions, including liver disease. Although there have been improvements in terms of awareness of AATD and understanding of its treatment in recent years, current challenges center on optimizing detection and management of patients with AATD, and improving access to intravenous (IV) AAT therapy - the only available pharmacological intervention that can slow disease progression. However, as an orphan disease with geographically dispersed patients, international cooperation is essential to address these issues. To achieve this, new European initiatives in the form of the European Reference Network for Rare Lung Diseases (ERN-LUNG) and the European Alpha-1 Research Collaboration (EARCO) have been established. These organizations are striving to address the current challenges in AATD, and provide a new platform for future research efforts in AATD. The first objectives of ERN-LUNG are to establish a quality control program for European AATD laboratories and create a disease management program for AATD, following the success of such programs in the United States. The main purpose of EARCO is to create a pan-European registry, with the aim of understanding the natural history of the disease and supporting the development of new treatment modalities in AATD and access to AAT therapy. Going further, other patient-centric initiatives involve improving the convenience of intravenous AAT therapy infusions through extended-interval dosing and self-administration. The present review will discuss the implementation of these initiatives and their potential contribution to the optimization of patient care in AATD., Competing Interests: Professor Joanna Chorostowska-Wynimko reports grants, personal fees, non-financial support from Grifols, Boehringer Ingelheim, and CSL Behring, personal fees, non-financial support from Novartis, and personal fees from GSK, outside the submitted work. Dr Miriam Barrecheguren reports personal fees from Grifols, Menarini, CSL Behring, GSK, Novartis, and Gebro Pharma, outside the submitted work. Dr Ilaria Ferrarotti reports personal fees from Grifols and grants from CSL Behring, outside the submitted work. Dr Timm Greulich reports personal fees from AstraZeneca, Berlin-Chemie, Boehringer-Ingelheim, Chiesi, CSL-Behring, Grifols, GSK, and Novartis, outside the submitted work. Professor Robert A Sandhaus reports participation in advisory boards for Grifols, CSL Behring, AstraZeneca, Mereo, and Inhibrx for which he receives reimbursement of travel expenses. Dr Michael Campos reports grants, non-financial support, and personal fees from CSL Behring, and grants and personal fees from Grifols, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2020 Chorostowska-Wynimko et al.)

Background and aim: The value of the forced expiratory volume in one second (FEV 1 ) is useful in the diagnosis and prognosis of chronic obstructive pulmonary disease (COPD). Previous studies on lung function in individuals with severe alpha-1 antitrypsin deficiency (AATD) have shown a variable annual decline in FEV 1 (∆FEV 1 ). The aim of this study was to analyze ∆FEV 1 and to identify risk factors for ∆FEV 1 in individuals with severe AATD. Material and methods: Data on smoking habits, symptoms, results of lung function tests and exacerbations were obtained from the Swedish AATD Register and the Swedish National Patient Register (SNPR). The ∆FEV 1 was analyzed by random-effects modeling and adjusted for age and FEV 1 at baseline. Results: One hundred and four (9%) current smokers, 539 (48%) ex-smokers and 489 (43%) never-smokers were included in the study and followed-up from 1991 to 2016. A total of 584 (52%) individuals with severe AATD had COPD at inclusion. The median (IQR) annual severe exacerbation rate was 0.66 (1.4). The adjusted mean ∆FEV 1 was significantly higher in the current smokers compared with the ex-smokers and never-smokers (70 [95% CI 56-83] vs 42 [95% CI 36-48] and 32 [95% CI 25-38) mL·yr -1 ], in the middle-aged individuals compared with the young individuals (48 [95% CI 41-55] vs 32 [95% CI 18-45] mL·yr -1 ), in the individuals with respiratory symptoms at inclusion compared with the asymptomatic individuals (46 [95% CI 40-52] vs 30 [95% CI 22-38]mL·yr -1 ), and in the individuals with frequent exacerbations compared with those with infrequent exacerbations (57 [95% CI 47-68] vs 27 [95% CI 17-37] mL·yr -1 ). Conclusion: Active smoking, age, respiratory symptoms at baseline and repeated severe exacerbations of COPD are factors associated with an accelerated decline of lung function in individuals with severe AATD., Competing Interests: The authors alone are responsible for the content and writing of the paper. The authors report no conflicts of interest in this work.

Endobronchial coil treatment (ECT) is a minimally invasive procedure developed for palliative care of patients with severe emphysema. ECT has demonstrated a decrease in hyperinflation, an improvement in quality of life, and an acceptable safety profile in randomized controlled trials (RCTs). Because alpha-1 antitrypsin deficiency (AATD) is a classical exclusion criterion in RCTs, there is no available data for ECT in AATD. In this post hoc analysis of the REVOLENS study (Réduction volumique endobronchique par spirales; ClinicalTrials.gov Identifier: NCT01822795), a multicenter 1:1 RCT which compared bilateral ECT with usual care in severe emphysema, we analyzed the efficacy and safety results at 1 year in six patients with AATD (five males, one female; mean age: 52±9 years) who underwent ECT. A significant decrease in hyperinflation (0.35 L decrease in residual volume [RV]) was observed in four out of six patients at 6 months and three out of six patients at 12 months, and an improvement in quality of life (improvement of 4 points in the St George's Respiratory Questionnaire [SGRQ]) was observed in four out of six patients at both 6 and 12 months. Efficacy results at 6 and 12 months from the six AATD patients were compared with 84 non-AATD patients who underwent ECT, and no statistically significant differences were found for FEV 1 , RV, 6MWT score and SGRQ score. Respiratory-related serious adverse event was limited to pneumonia in one AATD patient at 1 year post-ECT. This post hoc study suggests that AATD patients may have similar efficacy and safety outcomes at 1 year as non-AATD patients. Because of the paucity of available data, appropriately powered studies are needed to determine the effects of ECT in AATD., Competing Interests: Disclosure Gaëtan Deslee has been involved as an investigator in previous studies sponsored by BTG/PneumRx, and received travel reimbursements and speaker fees for educational sessions and consulting from BTG/PneumRx. Hervé Mal received honorarium from Boehringer, Bayer, Roche, Astellas, Chiesi, Actellion, Pfizer, Novartis, and GlaxoSmithKline outside the submitted work. Hervé Dutau received travel reimbursements and speaker fees for educational sessions and consulting from BTG/PneumRx. Arnaud Bourdin received honorarium from Astra Zeneca, GlaxoSmithKline, Boehringer, Novartis, Teva, Chiesi, Actellion, Gilead, and Roche outside the submitted work. Jean Michel Vergnon received travel reimbursements and speaker fees for educational sessions from BTG/PneumRx. Christophe Pison received honorarium from BTG/PneumRx and his hospital received funds to conduct trials from Holaira, PulmonX, and BTG/PneumRx. Charles Hugo Marquette has been involved as an investigator in previous studies sponsored by BTG/PneumRx, and received travel reimbursements and speaker fees for educational sessions and consulting from BTG/PneumRx. The authors report no other conflicts of interest in this work.

Background: The aim of the study was to assess the relationship between computed tomography (CT) densitometry and routine clinical markers in patients with chronic obstructive pulmonary disease (COPD) and alpha-1 anti-trypsin deficiency (AATD)., Methods: Multiple databases were searched using a combination of pertinent terms and those articles relating quantitatively measured CT densitometry to clinical outcomes. Studies that used visual scoring only were excluded, as were those measured in expiration only. A thorough review of abstracts and full manuscripts was conducted by 2 reviewers; data extraction and assessment of bias was conducted by 1 reviewer and the 4 reviewers independently assessed for quality. Pooled correlation coefficients were calculated, and heterogeneity was explored., Results: A total of 112 studies were identified, 82 being suitable for meta-analysis. The most commonly used density threshold was -950 HU, and a significant association between CT density and all included clinical parameters was demonstrated. There was marked heterogeneity between studies secondary to large variety of disease severity within commonly included cohorts and differences in CT acquisition parameters., Conclusion: CT density shows a good relationship to clinically relevant parameters; however, study heterogeneity and lack of longitudinal data mean that it is difficult to compare studies or derive a minimal clinically important difference. We recommend that international consensus is reached to standardize CT conduct and analysis in future COPD and AATD studies., Competing Interests: Disclosure AMT has received honoraria, research grants or educational grants from or acted as an investigator in trials for Boehringer Ingelheim, Novartis, Chiesi, GSK, AstraZeneca and Pfizer. The authors report no other conflicts of interest in this work.

Alpha-1 antitrypsin deficiency (AATD) is a condition caused by the inheritance of two mutated SERPINA1 gene alleles. Individuals with AATD are at increased risk of injury to the liver and lungs. The pulmonary manifestations include precocious onset of pulmonary emphysema and bronchiectasis. For nearly three decades, treatment has been available to individuals with emphysema caused by AATD, but this therapy-augmentation of plasma and tissue alpha-1 antitrypsin levels by intravenous administration of human plasma-derived protein-was approved by regulatory authorities based on its biochemical efficacy. This therapy appears to slow the progression of emphysema in patients with AATD. The medical, patient, and regulatory communities have sought assurance that this expensive therapy provides measurable clinical benefit. Documenting such benefit has been difficult because of the slow progression of the underlying lung disease in AATD, the rarity of this genetic condition, and the lack of direct quantitative measurements of emphysema progression. Over the past decade, quantitative computed tomography (CT) densitometry of the lungs has been found to correlate with severity and progression of emphysema. The recent publication of a well-powered, masked, placebo-controlled study using CT densitometry to evaluate the effectiveness of augmentation therapy at slowing the progression of emphysema has provided some assurance of the clinical efficacy of this therapy.

Alpha-1 antitrypsin (AAT) deficiency, characterized by low plasma levels of the serine protease inhibitor AAT, is associated with emphysema secondary to insufficient protection of the lung from neutrophil proteases. Although AAT augmentation therapy with purified AAT protein is efficacious, it requires weekly to monthly intravenous infusion of AAT purified from pooled human plasma, has the risk of viral contamination and allergic reactions, and is costly. As an alternative, gene therapy offers the advantage of single administration, eliminating the burden of protein infusion, and reduced risks and costs. The focus of this review is to describe the various strategies for AAT gene therapy for the pulmonary manifestations of AAT deficiency and the state of the art in bringing AAT gene therapy to the bedside.

Background: α1-antitrypsin is an antiprotease that is mainly produced in the liver; it plays a crucial role in the protection of lung parenchyma against the destructive effects of proteases. Mutations in the α1-antitrypsin gene can cause α1-antitrypsin deficiency. Individuals homozygous for the Z-genotype have drastically lowered serum α1-antitrypsine concentrations and often develop lung emphysema at an early age., Case Description: A 38-year-old woman and her 43-year-old sister both developed lung emphysema at an early age; this could be attributed to severe α1-antitrypsin deficiency. The only treatment for this condition is α1-antitrypsin supplement therapy, but this therapy is not reimbursed by health insurance companies in the Netherlands., Conclusion: α1-antitrypsin deficiency is a relatively rare cause of lung emphysema and can be seen as an orphan phenotype of chronic obstructive pulmonary disease (COPD). We appeal for reconsideration of coverage of α1-antitrypsine supplement therapy by basic health insurance in the Netherlands, on the basis of a recent randomised placebo-controlled study in which the protective effect of this therapy on progressive emphysema was demonstrated by CT lung densitometry.

Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disease that creates multiple unique phenotypes of chronic obstructive pulmonary disease. While bronchospasm, cough, dyspnea, and sputum production all occur with AATD, the phenotypic differences require a computed tomographic (CT) scan to decipher. The availability of augmentation therapy in the United States since 1989 has generated both controversy and evidence that informs the science of usual chronic obstructive pulmonary disease (COPD). Because of the predominance of emphysema in AATD, much of the best evidence concerning biomarkers of emphysema progression comes from this population. Imaging measurement of emphysema progression, impact of emphysema phenotypes on hyperinflation and dynamic hyperinflation, and correlation with traditional spirometric measures of COPD progression are required to understand the impact of AAT therapies. These studies are important for better understanding of usual COPD pathogenesis. Significantly, there are no adequately powered research studies to determine if augmentation therapy is helpful for the non-emphysema phenotypes of AATD. Specifically, phenotypes of chronic bronchitis, asthma predominant disease, and bronchiectasis will require targeted research studies to define optimal therapy., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

This article reports a case of febrile, symmetrical and painful soft tissue swelling on both thighs in a 54-year-old otherwise healthy male patient. Histologically, necrotizing panniculitis of subcutaneous adipose tissue was described as a marker manifestation of a previously unknown alpha-1-antitrypsin (A1AT) deficiency with pulmonary emphysema and low plasma A1AT levels. The PiZZ homozygous form of A1AT could be diagnosed by gene sequencing. Complete remission of panniculitis could be achieved by A1AT replacement therapy.

α-1-antitrypsin deficiency (A1ATD) is an under-recognized hereditary disorder associated with the premature onset of chronic obstructive pulmonary disease. There is considerable heterogeneity in the phenotypic expression of lung disease in A1ATD and the pathophysiology is complex, involving the interaction of multiple pathways. Other genetic factors that may contribute to emphysema risk in A1AT-deficient individuals are beginning to be identified. Methods of monitoring disease progression have evolved, including the use of computed tomography densitometry and biomarkers of disease activity. Progress in the development of novel treatment strategies continues, including the hope for a potential cure through the use of gene therapies. In this article, the authors review the recent advances in this field and outline potential future directions of research in A1ATD.

The aim of the present study was to identify alpha(1)-antitrypsin (alpha(1)-AT)-deficient patients who had rapidly progressive disease. PiZ patients (n = 101) underwent annual lung function measurements over a 3-yr period, and the results were related to factors that may influence decline. The mean annual decline in forced expiratory volume in 1 s (FEV(1)) was 49.9 mL. The greatest FEV(1) decline occurred in the moderate severity group (FEV(1) 50-80% of the predicted value), with a mean annual decline of 90.1 mL, compared with 8.1 mL in the very severe group (FEV(1) <30% pred). However, annual decline in transfer coefficient of the lung for carbon monoxide (K(CO)) was greatest in the severe and very severe groups. When the whole group was divided into tertiles of FEV(1) decline, the fast tertile compared with the slow tertile had more patients with bronchodilator reversibility (BDR) (73 versus 41%; p = 0.010), more males (79 versus 56%; p = 0.048) and lower body mass index (BMI) (24.0 versus 26.1; p = 0.042). Logistic regression analyses confirmed that FEV(1) decline was independently associated with BMI, BDR, exacerbation rate and high physical component 36-item short-form health survey scores. In PiZ alpha(1)-AT-deficient patients, FEV(1) decline was greatest in moderate disease, unlike K(CO) decline, which was greatest in severe disease. The FEV(1) decline showed associations with BDR, BMI, sex and exacerbation rate.

Currently, A1AD is recognized in approximately 2% of patients who have emphysema, although this may be an underestimation of the prevalence of this disease. Given the relatively young age at which patients who have A1AD present with emphysema, therapies aimed at slowing the progression of this disease are imperative. In addition to abstaining from smoking, the use of augmentation therapy may benefit some patients who have moderate airflow obstruction. For patients who have severe airflow obstruction, the most effective therapy is surgical. Despite a possible increased risk for infectious complications, transplantation remains a viable option for these patients who have long-term results mirroring those of patients transplanted for smoking-related COPD. Given limited donor availability, however, LVRS must be considered in these patients possibly as definitive therapy but more likely as a bridge to transplantation. LVRS for patients who have A1AD remains relatively uncommon despite a general perception that it remains a surgical option. In a survey of European thoracic surgical centers, Hamacher and colleagues42 found that two thirds of respondents included A1AD in their list of indications for LVRS. Although the durability of the benefits derived from LVRS in patients who have A1AD seems inferior to that of patients who have COPD, the available data show improved 6-minute walk distances and decreased dyspnea persisting for 1 to 2 years after LVRS in patients who had A1AD. Further experience is necessary to determine whether or not subgroups of patients who have A1AD, such as those who have clear heterogeneous distribution, may derive more long-lasting improvement from LVRS.

Complex biological systems are often shaped and maintained by opposing forces. A relevant biological example is the delicate balance between proteases and their inhibitors. Serine proteases contain a serine residue in the active site of the molecule that is essential to the activity of the enzyme. Protease inhibitors limit the activity of proteases in the body. As examples, aprotinin (Trasylol), a serine protease inhibitor, and aminocaproic acid (Amicar), a lysine protease inhibitor, are used to decrease the rate of fibrinolysis and have recently been the subject of considerable controversy in the literature regarding safety and efficacy. This AANA journal course reviews 2 common examples of protease inhibitor disorders, angioedema and a form of emphysema, that are of particular anesthetic relevance.

Alpha-1-antitrypsin deficiency (AAT) is one of the three most common lethal genetic diseases in the caucasian population (together with cystic fibrosis and Down syndrome). Its primary manifestation is early-onset panacinar emphysema. Slowly progressive dyspnea is the primary symptom, although some patients initially have symptoms of cough, sputum production, or wheezing. A minority of patients develops hepatic cirrhosis. We present a case of a 40 year-old male, light smoker, with chronic obstructive lung disease with predominance of panacinar emphysema, with AAT deficiency (72 mg/dl; normal values = 200-300 mg/dl) complicated with cor pulmonale and chronic respiratory failure. The main clinical consequence of AAT deficiency is the early onset of panacinar emphysema, typically more severe at the lung bases. Smoking plays an important part in the natural history of the disease, both increasing the severity and decreasing the age at onset of emphysema.

Nonsmokers with signs of emphysema at an earlier age than is typical for emphysema deserve a workup for one of the less common causes of emphysema, which include alpha 1-antitrypsin deficiency, connective tissue diseases, hypocomplementemic urticarial vasculitis syndrome, intravenous drug use, human immunodeficiency virus infection, and several rare metabolic disorders.

Human plasma contains a number of proteinase inhibitors which together form 10% of the total plasma proteins. Serine proteases are a group of closely related proteolytic enzymes, with serine in their active site. These play a key role in coagulation, fibrinolysin, kinin and complement activation. Serine protease inhibitors or "serpins" are specific inhibitors which control the activities of these enzymes. Among the serine protease inhibitors. Alpha-1 antitrypsin (alpha1 ATD) is found in highest concentration in plasma. It is the major physiologic inhibitor for neutrophil elastase. It has control over the elastase mediated degradation of elastic tissue in the lung. Alpha1ATD deficiency is a common genetic disorder and potentially lethal disease predominantly found in North European population--where the incidence is one in 2500; worldwide figures suggest that one in 6000 people have classic alpha1ATD. In cases of deficiency, antielastase activity is reduced in the lungs which results in increased elastin breakdown and development of emphysema. Cigarette smoking contributes to destructive changes in emphysema by suppressing the proteinase inhibitory activity of human serum and by inducing certain bronchoalveolar changes. Prevalence and severity of asthma increases in persons with abnormal alpha1ATD phenotype.

alpha 1-antitrypsin (alpha 1-AT) deficiency is a genetic disorder characterized by low serum levels of alpha 1-AT and a high risk of pulmonary emphysema at a young age. The resulting surplus of proteases, mainly of neutrophil elastase, can be balanced by i.v. augmentation with alpha 1-AT. However, it is not clear if affected patients benefit from long-term augmentation therapy and no long-term safety data are available. We examined 443 patients with severe alpha 1-AT deficiency and pulmonary emphysema receiving weekly i.v. infusions of 60 mg/kg body weight alpha 1-AT in addition to their regular medication. The progression of the disease was assessed by repeated lung function measurements, particularly the decline in forced expiratory volume in 1 second (delta FEV1). 443 patients with alpha 1-AT deficiency tolerated augmentation therapy well with few adverse reactions. The delta FEV1 in 287 patients with available follow-up data was 57.1 +/- 31.1 ml per year. Stratified for baseline FEV1, the decline was 35.6 +/- 21.3 ml in the 108 patients with an initial FEV1 < 30% and 64.0 +/- 26.4 ml in the 164 with 30% < FEV1 < or = 65% of predicted normal (p = 0.0008). The remaining 15 patients had an initial FEV1 > 65%. Long-term treatment with i.v. alpha 1-antitrypsin in patients with severe alpha 1-Pi deficiency is feasible and safe. The decline in forced expiratory volume in one second is related to the initial forced expiratory volume in one second as in alpha 1-antitrypsin deficient patients not receiving augmentation therapy.