The proteinase-antiproteinase balance in alpha-1-proteinase inhibitor-deficient lung transplant recipients

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.

Clinical outcomes and survival following lung transplantation in patients with Alpha-1 antitrypsin deficiency

OBJECTIVE

The primary intention of our study is to describe disease-specific outcomes in patients with alpha-1 antitrypsin deficiency (AATD) following lung transplantation (LT).

METHODS

We reviewed the Organ Procurement and Transplant Network database to identify AATD patients who have undergone LT in the United States.

RESULTS

Two thousand two hundred and thirteen patients with AATD underwent LT between March 1992 and September 2019. A total of 1556 patients received LT with a median age at listing was 51 years. The median time spent on the LT waitlist was 263 days. The median ischemic time was 4.75 h. The Kaplan-Meier survival analysis following LT for AATD patients at 1-, 5-, and 10 years was 82%, 56%, and 34%, at 1-, 5-, and 10 years, respectively. The median survival time post-LT is 6.4 years (Interquartile range 5.6-6.8 years). The post-LT survival was significantly better in double LT compared to single LT (Median 7.7 vs 4.4 years, p < 0.001). Increasing age, presence of CMV mismatch, reintubation prior to discharge, and requiring treatment for rejection within one year of transplantation did impact post-LT mortality.

CONCLUSION

The median survival after LT in AATD is 6.4 years and is similar to other lung diseases. When compared to usual COPD LT, AATD patients have increased post-LT mortality due to infections and liver disease. Recipients of a double lung transplant had a favorable outcome compared to single lung transplant.

Implications of a Change of Paradigm in Alpha1 Antitrypsin Deficiency Augmentation Therapy: From Biochemical to Clinical Efficacy

Ever since the first studies, restoring proteinase imbalance in the lung has traditionally been considered as the main goal of alpha1 antitrypsin (AAT) replacement therapy. This strategy was therefore based on ensuring biochemical efficacy, identifying a protection threshold, and evaluating different dosage regimens. Subsequently, the publication of the results of the main clinical trials showing a decrease in the progression of pulmonary emphysema has led to a debate over a possible change in the main objective of treatment, from biochemical efficacy to clinical efficacy in terms of lung densitometry deterioration prevention. This new paradigm has produced a series controversies and unanswered questions which face clinicians managing AAT deficiency. In this review, the concepts that led to the approval of AAT replacement therapy are reviewed and discussed under a new prism of achieving clinical efficacy, with the reduction of lung deterioration as the main objective. Here, we propose the use of current knowledge and clinical experience to face existing challenges in different clinical scenarios, in order to help clinicians in decision-making, increase interest in the disease, and stimulate research in this field.

Greater survival despite increased complication rates following lung transplant for alpha-1-antitrypsin deficiency compared to chronic obstructive pulmonary disease

Background

Alpha-1-antitrypsin (A1AT) deficiency (A1ATD) is characterized by accelerated degradation of lung function. We examined our experience with lung transplantation for chronic obstructive pulmonary disease (COPD) with and without A1ATD to compare survival and rates of postoperative surgical complications.

Methods

Patients with A1ATD and non-A1ATD COPD undergoing lung transplantation from 1988-2015 at our institution were analyzed. Complications were categorized into non-gastroenteritis gastrointestinal (GI), wound, airway, and reoperation for bleeding. Overall and complication-free survival were evaluated using Kaplan-Meier curves and Cox proportional hazards models.

Results

Three hundred and eighty-five patients underwent lung transplant for COPD (98 A1ATD). For A1ATD, 56.1% underwent single lung transplantation (80.6% for COPD). Early overall and complication-free survival was worse for A1ATD, but this trend reversed at longer follow up. Unadjusted estimated survival showed advantage for COPD at 90 days and 1 year, which attenuated by 5 years and reversed at 10 years (P<0.001). On adjusted analysis, A1ATD was associated with a trend toward lower complication-free survival at 90 days and 1 year, due partly to increased rates of post-transplant GI pathology, particularly in the era of the lung allocation score (LAS).

Conclusions

A1ATD lung recipients had worse short-term complication-free survival but improved long-term survival compared to COPD patients. A1ATD was associated with greater risk of new GI pathology after transplant. Close monitoring of A1ATD patients with timely evaluation of GI complaints after transplant is warranted.

European Respiratory Society statement: diagnosis and treatment of pulmonary disease in α1-antitrypsin deficiency

α1-antitrypsin deficiency (AATD) is the most common hereditary disorder in adults. It is associated with an increased risk of developing pulmonary emphysema and liver disease. The pulmonary emphysema in AATD is strongly linked to smoking, but even a proportion of never-smokers develop progressive lung disease. A large proportion of individuals affected remain undiagnosed and therefore without access to appropriate care and treatment.

The most recent international statement on AATD was published by the American Thoracic Society and the European Respiratory Society in 2003. Since then there has been a continuous development of novel, more accurate and less expensive genetic diagnostic methods. Furthermore, new outcome parameters have been developed and validated for use in clinical trials and a new series of observational and randomised clinical trials have provided more evidence concerning the efficacy and safety of augmentation therapy, the only specific treatment available for the pulmonary disease associated with AATD.

As AATD is a rare disease, it is crucial to organise national and international registries and collect information prospectively about the natural history of the disease. Management of AATD patients must be supervised by national or regional expert centres and inequalities in access to therapies across Europe should be addressed.

Alpha-1 proteinase inhibitors for the treatment of alpha-1 antitrypsin deficiency: safety, tolerability, and patient outcomes

Alpha-1 antitrypsin (AAT) deficiency remains an underrecognized genetic disease with predominantly pulmonary and hepatic manifestations. AAT is derived primarily from hepatocytes; however, macrophages and neutrophils are secondary sources. As the natural physiological inhibitor of several proteases, most importantly neutrophil elastase (NE), it plays a key role in maintaining pulmonary protease–antiprotease balance. In deficient states, unrestrained NE activity promotes damage to the lung matrix, causing structural defects and impairing host defenses. The commonest form of AAT deficiency results in a mutated Z AAT that is abnormally folded, polymerized, and aggregated in the liver. Consequently, systemic levels are lower, resulting in diminished pulmonary concentrations. Hepatic disease occurs due to liver aggregation of the protein, while lung destruction ensues from unopposed protease-mediated damage. In this review, we will discuss AAT deficiency, its clinical manifestations, and augmentation therapy. We will address the safety and tolerability profiles of AAT replacement in the context of patient outcomes and cost-effectiveness and outline future directions for work in this field.

The natural history of lung function after lung transplantation for α(1)-antitrypsin deficiency

RATIONALE

Lung transplantation (LT) is an established treatment for end-stage lung diseases, including chronic obstructive pulmonary disease (COPD) associated with α1-antitrypsin deficiency (AATD).

OBJECTIVES

We sought to compare the post-transplantation course of patients with AATD and AAT-replete COPD.

METHODS

Between June 1991 and January 2008, a total of 231 patients with AAT-replete COPD and 45 with AATD underwent LT at Cleveland Clinic. Data reviewed included baseline recipient, donor, and surgical data; all spirometry evaluations; acute cellular rejection (ACR) events; and survival data. Endpoints included temporal change in FEV1, severity of ACR, and survival. A longitudinal temporal decomposition model was used for analysis.

MEASUREMENTS AND MAIN RESULTS

Comparison of overall rates of FEV1 decline in AATD and AAT-replete patients with COPD showed no significant differences (P > 0.09). However, although the single LT patients had similar trends in FEV1 in both groups, patients with AATD with double LT declined faster (P < 0.002) than the AAT-replete patients. No differences in the frequency or severity of ACR episodes were observed (P = 0.32). Furthermore, there was no difference in early or late mortality between patients with AATD and patients with AAT-replete COPD (P > 0.09).

CONCLUSIONS

Although overall the post-LT FEV1 slope, severity of ACR, and survival among patients with AATD is similar to that of AAT-replete patients with COPD, patients with AATD with double LT have a faster rate of FEV1 decline. These findings support the eligibility of patients with AATD for LT, and suggest the need for additional studies to better understand the difference between single and double LT in AATD.

Neutrophil necrosis and annexin 1 degradation associated with airway inflammation in lung transplant recipients with cystic fibrosis

Background

Neutrophils sequestered in lower respiratory tract secretions in the inflamed lung may undergo apoptosis and/or necrosis and release toxic cellular contents that can injure airways or parenchyma. This study examined the viability of neutrophils retrieved from the proximal airways of lung transplant recipients with bacterial tracheobronchitis.

Methods

Integrity and stability of intracellular proteins in neutrophils from proximal airways and peripheral blood from lung transplant recipients with bacterial tracheobronchitis were analyzed via Western blot analysis and determination of neutrophil viability by morphologic appearance and flow cytometry.

Results

Neutrophils in tracheobronchial secretions from lung transplant recipients with cystic fibrosis who had normal chest radiographic imaging but bronchoscopic evidence of purulent tracheobronchitis post-transplant were necrotic and associated with degradation of intracellular protein annexin 1. The neutrophil influx was compartmentalized to large airways and not detected in peripheral bronchoalveolar airspaces sampled via bronchoalveolar lavage. Peripheral blood neutrophils from healthy subjects cultured in vitro demonstrated that annexin 1 degradation, particularly to a 33 kDa annexin 1 breakdown product (A1-BP), was associated with neutrophil necrosis, but not apoptosis. Although annexin 1 degradation was not specific to neutrophil necrosis, it was a sensitive marker of intracellular protein degradation associated with neutrophil necrosis. Annexin 1 degradation to 33 kDa A1-BP was not observed in peripheral blood neutrophils from healthy subjects, but annexin 1 appeared to be degraded in peripheral blood neutrophils of lung transplant recipients despite a normal morphologic appearance of these cells.

Conclusions

Neutrophils were necrotic from the proximal airways of lung transplant recipients with bacterial tracheobronchitis, and this process may begin when neutrophils are still in the systemic circulation prior to sequestration in inflamed airways. Annexin 1 degradation to 33 kDa A1-BP may be useful as a sensitive marker to detect neutrophil necrosis.

A review of augmentation therapy for alpha-1 antitrypsin deficiency

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is a relatively common, but under-recognized condition which manifests commonly with liver cirrhosis and emphysema. Specific therapy for lung-affected individuals with AATD is augmentation therapy, which consists of intravenous infusion of purified human plasma-derived alpha-1 antitrypsin (AAT). Augmentation therapy was first approved by the United States Food and Drug Administration (FDA) in 1987 for emphysema associated with severe AATD and today, six augmentation therapy preparations, all of which derive from pooled human plasma, have received FDA approval.

AREAS COVERED

This paper reviews augmentation therapy for AATD, including the various available commercial preparations, their processing and biochemical differences, evidence regarding biochemical and clinical efficacy, patterns of clinical use, adverse effect profiles, cost-effectiveness and potential uses in conditions other than emphysema associated with AATD. Novel and emerging strategies for treating AATD are briefly discussed next, including alternative dosing and administration strategies, recombinant preparations, small molecule inhibitors of neutrophil elastase and of AAT polymerization, autophagy-enhancing drugs and gene therapy approaches.

EXPERT OPINION

We conclude with a discussion of our approach to managing patients with AATD and use of augmentation therapy.

Augmentation therapy in alpha-1 antitrypsin deficiency: advances and controversies

Alpha-1 antitrypsin (AAT) deficiency is a hereditary condition characterized by low levels of AAT in plasma and hence diffusion into tissues. One of the most relevant characteristics of the disease is the development of panacinar emphysema due to an imbalance between proteases and antiproteases in the presence of environmental triggers. Left untreated, severe obstructive lung disease may develop. Avoidance of environmental triggers such as cigarette smoking constitutes a critical component of AAT deficiency treatment. Intravenous augmentation therapy is the only specific therapy for the condition that has been approved by the US Food and Drug Administration (FDA). While this therapy likely slows the rate of progression of emphysema and may improve survival in selected individuals with severe AAT deficiency, the gold standard for proof of efficacy is lacking. Areas where controversy exists regarding the use of AAT augmentation therapy include: (1) indications for treatment, (2) selection of specific AAT augmentation therapy, (3) appropriate dose and interval of administration, (4) cost effectiveness, (5) frequency and mode of follow up of treated patients, (6) use of augmentation therapy after lung transplantation, (7) use of recombinant AAT supplementation, (8) alternative delivery routes, and (9) genetic therapy. In this review we describe the advances in treatment and try to address some of the current controversies in AAT deficiency management.

Therapy for alpha1-antitrypsin deficiency: pharmacology and clinical recommendations

Alpha1-antitrypsin (A1AT) deficiency is inherited as an autosomal codominant disorder characterised by reduced levels of A1AT in the serum. Low levels of A1AT in blood perfusing the lung cause low levels in the lung interstitium, making it susceptible to proteolytic damage from resident neutrophil elastase. A 'protective threshold' serum A1AT level of 11 micromol/L has been identified by epidemiological studies as a minimum value below which there is an increased risk of emphysema. Intravenous augmentation therapy for patients with severe deficiency of A1AT has been shown to have biochemical efficacy. Although the clinical efficacy of intravenous augmentation therapy has not been demonstrated in a randomised clinical trial, available studies suggest that augmentation therapy is associated with a slowed rate of decline of lung function and enhanced survival. The criteria for patient selection include: age >18 years, serum A1AT level <or=11 micromol/L, a high-risk phenotype (usually PI*ZZ), and documented fixed airflow obstruction (consistent with chronic obstructive pulmonary disease). Although intravenous augmentation is currently the only form of specific therapy approved in the US, active research in the fields of aerosol and gene therapy promise to offer new treatment prospects. In this article, we review the available literature on A1AT augmentation therapy and discuss our recommendations.

Safety and efficacy of alpha-1-antitrypsin augmentation therapy in the treatment of patients with alpha-1-antitrypsin deficiency

Alpha-1-antitrypsin deficiency (AATD), also known as alpha1-proteinase inhibitor deficiency, is an autosomal co-dominant condition. The genotypes associated with AATD include null, deficient, and dysfunctional alpha-1-antitrypsin (A1AT) variants, which result in low levels of circulating functional A1AT, unbalanced protease activity, and an increased risk of developing lung emphysema, the leading cause of morbidity in these patients. Furthermore, the most common abnormal genotype, Pi*ZZ may also cause trapping of abnormally folded protein polymers in hepatocytes causing liver dysfunction. A major focus of therapy for patients with lung disease due to AATD is to correct the A1AT deficiency state by augmenting serum levels with intravenous infusions of human plasma-derived A1AT. This strategy has been associated with effective elevations of A1AT levels and function in serum and lung epithelial fluid and observational studies suggest that it may lead to attenuation in lung function decline, particularly in patients with moderate impairment of lung function. In addition, an observational study suggests that augmentation therapy is associated with a reduction of mortality in subjects with AATD and moderate to severe lung impairment. More recent randomized placebo-controlled studies utilizing computer scan densitometry suggest that this therapy attenuates lung tissue loss. Augmentation therapy has a relative paucity of side effects, but it is highly expensive. Therefore, this therapy is recommended for patients with AATD who have a high-risk A1AT genotype with plasma A1AT below protective levels (11 μM) and evidence of obstructive lung disease. In this article, we review the published evidence of A1AT augmentation therapy efficacy, side effects, and safety profile.

Alpha-1-Antitrypsin Deficiency: Current Concepts

Since the condition was first described four decades ago, alpha-1-antitrypsin (A1AT) deficiency has served as a model for other disease processes. A1AT is the archetypal serpin designed to ensnare proteases, a process that involves significant conformational change within the molecule. Mutations in the A1AT gene lead to misfolding of the protein and accumulation within the endoplasmic reticulum of hepatocytes resulting in two different pathologic processes. First, the accumulation of mutant A1AT protein has a directly toxic effect on the liver, resulting in hepatitis and cirrhosis. Second, the resultant decrease in circulating A1AT results in protease-antiprotease imbalance at the lung surface and emphysema ensues. A1AT deficiency therefore can be seen as two distinct disease processes: a conformational disease of the liver and a protease-antiprotease imbalance of the lung. This two-stage model of disease in A1AT deficiency is elegant in its simplicity and goes a long way to explaining the clinical manifestations that occur in patients with the condition. However, some aspects of the disease are not readily explained. Recent findings suggest that there is more to the lung damage in A1AT deficiency than simple proteolytic insult and that the presence of the mutant protein itself is proinflammatory and may indeed cause chronic injury to the cells that produce it. This review discusses some of the emerging concepts in alpha-1-antitrypsin research and outlines the implications these new ideas may have for treatment of this condition.

The Selective Advantage of α1-Antitrypsin Deficiency

The S- and Z-deficiency alleles of alpha1-antitrypsin are found in more than 20% of some white populations. This high gene frequency suggests that these mutations confer a selective advantage, but the biologic mechanism of this has remained obscure. It is now well recognized that the S and Z alleles result in a conformational transition within the alpha1-antitrypsin molecule and the formation of polymers that are retained within the endoplasmic reticulum of hepatocytes. Polymers of mutant alpha1-antitrypsin can also form within the alveoli and small airways of the lung where they may drive the inflammation that underlies emphysema in individuals with alpha1-antitrypsin deficiency. This local production of polymers by mutant S and Z alpha1-antitrypsin may have also provided protection against infectious disease in the preantibiotic era by focusing and amplifying the inflammatory response to limit invasive respiratory and gastrointestinal infection. It is only since the discovery of antibiotics, the widespread adoption of smoking, and increased longevity that these protective, proinflammatory properties of alpha1-antitrypsin mutants have become detrimental to cause the emphysema and systemic inflammatory diseases associated with alpha1-antitrypsin deficiency.

Recurrence of Pulmonary Emphysema in an α-1 Proteinase Inhibitor-deficient Lung Transplant Recipient

Several types of primary disease may recur after lung transplantation, but recurrence of pulmonary emphysema has so far never been published. We report the case of a 49-year-old white male who underwent single lung transplantation for emphysema related to alpha-1 antitrypsin deficiency and to superimposed smoking. The postoperative course was complicated by several rejection episodes. Subsequently, the patient remained stable without evidence of graft dysfunction for more than 10 years, but he resumed light smoking at 8 years after transplant. At 11 years after transplant, although the patient was still asymptomatic and had a stable lung function, recurrence of emphysema on the grafted side was diagnosed on computerized tomography of the thorax. One year later, the patient began to experience a moderate decline in lung function. Two separate bronchoalveolar lavages performed after the onset of the recurrence disclosed a significant elastolytic activity related to neutrophil serine-elastase in lavage fluid. In summary, we describe a case of recurrence of pulmonary emphysema in a patient with alpha-1 antitrypsin deficiency. The resumption of smoking has probably played a central role in the presence of elastolytic activity in lavage fluid and in the recurrence of emphysema.

Emphysema: the challenge of the remodelled lung

Emphysema is recognized as the component of chronic obstructive airways disease that is responsible for airways obstruction. Different patterns of emphysema are, however, recognized, suggesting possible different pathogenetic processes within the lung. This, coupled with the associated idea of susceptibility factors to the development of emphysema, has led to studies of genes that may be involved in the defence of the lung from proteolytic and oxidative damage. These studies have been driven by the goal of finding a treatment for emphysema, but appear to have lost sight of the fundamental remodelling of the lung that has occurred in patients with emphysema and the fact that it is not a single morphological entity.

Neutrophils, unopposed neutrophil elastase, and alpha1-antiprotease defenses following human lung transplantation

Neutrophils are sequestered in the newly transplanted lung after reperfusion or with infection, rejection, and chronic graft dysfunction. Because unopposed (free) neutrophil elastase (NE) released into bronchoalveolar secretions may injure the lung allograft and impair bacterial clearance, we assessed total neutrophil numbers, myeloperoxidase activity as an index of neutrophil influx and degranulation, alpha1-antiprotease (alpha1-AP) concentrations, and unopposed NE activity in bronchoalveolar secretions from lung transplant recipients. Unopposed NE activity was present in bronchoalveolar lavage fluid (BALF) from recipients transplanted for emphysema associated with alpha1-AP deficiency as well as recipients without such deficiency (171 of 2,137 BALF; 8%). Ten of 17 (59%) recipients with alpha1-AP deficiency who were followed for at least 1 yr after transplant with multiple surveillance and diagnostic bronchoscopies had at least one BALF containing unopposed NE, usually associated with the presence of > or = 10(5) colony forming units/ml BALF of aerobic bacteria. In contrast, 19 of 58 (33%) with emphysema not associated with alpha1-AP deficiency, 8 of 32 (25%) recipients with cystic fibrosis (CF), 6 of 16 (38%) with idiopathic pulmonary fibrosis (IPF), and 11 of 36 (31%) with other indications for transplant had unopposed NE in BALF. alpha1-AP levels were significantly elevated in the early posttransplant time period and could be augmented considerably in alpha1-AP-deficient recipients with episodes of infection or rejection. Our findings indicate that unopposed NE activity can be found in both alpha1-AP-deficient and alpha1-AP-sufficient recipients after transplantation, usually in association with endobronchial bacterial infection.

Alpha1-antitrypsin deficiency: biological answers to clinical questions

Alpha1-antitrypsin (alpha1AT) deficiency is a common lethal hereditary disorder of white persons of European descent. The condition is characterized by reduced serum levels of alpha1AT, a 52-kDa glycoprotein synthesized chiefly in the liver and, to a lesser extent, by macrophages and neutrophils. Alpha1AT acts as an antiprotease and is the physiological inhibitor of neutrophil serine proteases such as neutrophil elastase cathepsin G and proteinase 3. The clinical manifestations of alpha1AT deficiency occur chiefly in the lung, with a high risk of emphysema occurring by the third or fourth decade of life. Cigarette smoking accelerates the development of emphysema in persons with alpha1AT deficiency. There is also an increased risk of liver disease in alpha1AT deficiency, which occurs mostly in childhood. In this review, we will define further the diagnosis of alpha1AT deficiency and its clinical manifestations and describe the therapeutic strategies that are currently being developed to treat the hepatic and pulmonary disease associated with this condition.

Lung transplantation. A disease-specific approach

Lung transplantation has emerged as a viable option for the treatment of end-stage disease attributable to a wide spectrum of primary disorders. Although many aspects of patient management are indifferent to the underlying indication, important differences related to timing of transplantation, selection of candidates, choice of procedure, and post-transplant complications exist among the various primary disease groups. Optimal utilization of transplantation for these challenging patient populations with advanced lung disease mandates a thorough appreciation of those differences.

The proteinase-antiproteinase theory of emphysema: a speculative analysis of recent advances into the pathogenesis of emphysema

This review concerns the reasons why only an estimated 10-15% of patients with alpha-1-antitrypsin (A1AT) deficiency develop the destructive lung disease known as emphysema. The arguments presented revolve around the proteinase-antiproteinase balance in the 'microenvironment' of the epithelial space of the lung. Attention is focused on the balance between destructive enzymes such as neutrophil elastase and protective proteins such as A1AT, secretory leucocyte proteinase inhibitor (SLPI), human elastase inhibitor (HEI) and elafin. When neutrophil elastase is already attached to the elastin fibres the smaller molecules SLPI and elafin appear to be better inhibitors of this enzyme than larger inhibitors such as A1AT and HEI. Furthermore, SLPI and elafin may provide the first line of defence against proteinase attack from neutrophil elastase. In trying to explain the variability in the clinical expression of A1AT-deficiency and the development of emphysema, the importance of changes to A1AT, SLPI and elafin molecules induced by smoking and/or oxygen free radicals has been considered. It is possible that emphysema only develops in patients who have SLPI/elafin deficiency as well as A1AT deficiency.

Lung transplantation for alpha 1-antitrypsin deficiency emphysema

Lung transplantation is an option for appropriately selected patients with end-stage emphysema caused by alpha 1-antitrypsin deficiency. The functional results have been excellent after single or bilateral lung transplantation, and the medium-term survival results have been good. However, the role of alpha 1-antitrypsin replacement therapy after lung transplantation remains uncertain, and further investigation is needed.

Recent pulmonary observations in alpha 1-antitrypsin deficiency, primary biliary cirrhosis, chronic hepatitis C, and other hepatic problems

Patients with metabolic, immunologic, viral, and other types of hepatic disorders can have a spectrum of complicating pulmonary abnormalities. The natural history of these associations is poorly understood. Significant reversibility in hepatic and pulmonary dysfunction, however, has been well documented in the era of organ transplantation. The continued relationship among pulmonologists, hepatologists, and transplant surgeons hopefully will provide enlightening data on these interesting clinical associations, their natural histories, and their response to evolving therapeutic approaches.