Alpha1-antitrypsin Review

Protein Posttranslational Signatures Identified in COVID-19 Patient Plasma

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a highly contagious virus of the coronavirus family that causes coronavirus disease-19 (COVID-19) in humans and a number of animal species. COVID-19 has rapidly propagated in the world in the past 2 years, causing a global pandemic. Here, we performed proteomic analysis of plasma samples from COVID-19 patients compared to healthy control donors in an exploratory study to gain insights into protein-level changes in the patients caused by SARS-CoV-2 infection and to identify potential proteomic and posttranslational signatures of this disease. Our results suggest a global change in protein processing and regulation that occurs in response to SARS-CoV-2, and the existence of a posttranslational COVID-19 signature that includes an elevation in threonine phosphorylation, a change in glycosylation, and a decrease in arginylation, an emerging posttranslational modification not previously implicated in infectious disease. This study provides a resource for COVID-19 researchers and, longer term, and will inform our understanding of this disease and its treatment.

Extracellular Vesicles as Central Mediators of COPD Pathophysiology

Chronic obstructive pulmonary disease (COPD) is a complex, heterogeneous, smoking-related disease of significant global impact. The complex biology of COPD is ultimately driven by a few interrelated processes, including proteolytic tissue remodeling, innate immune inflammation, derangements of the host-pathogen response, aberrant cellular phenotype switching, and cellular senescence, among others. Each of these processes are engendered and perpetuated by cells modulating their environment or each other. Extracellular vesicles (EVs) are powerful effectors that allow cells to perform a diverse array of functions on both adjacent and distant tissues, and their pleiotropic nature is only beginning to be appreciated. As such, EVs are candidates to play major roles in these fundamental mechanisms of disease behind COPD. Furthermore, some such roles for EVs are already established, and EVs are implicated in significant aspects of COPD pathogenesis. Here, we discuss known and potential ways that EVs modulate the environment of their originating cells to contribute to the processes that underlie COPD.

A novel in vivo model for extracellular vesicle-induced emphysema

Chronic obstructive pulmonary disease (COPD) is a debilitating chronic disease and the third-leading cause of mortality worldwide. It is characterized by airway neutrophilia, promoting tissue injury through release of toxic mediators and proteases. Recently, it has been shown that neutrophil-derived extracellular vesicles (EVs) from lungs of patients with COPD can cause a neutrophil elastase–dependent (NE-dependent) COPD-like disease upon transfer to mouse airways. However, in vivo preclinical models elucidating the impact of EVs on disease are lacking, delaying opportunities for therapeutic testing. Here, we developed an in vivo preclinical mouse model of lung EV–induced COPD. EVs from in vivo LPS-activated mouse neutrophils induced COPD-like disease in naive recipients through an α-1 antitrypsin–resistant, NE-dependent mechanism. Together, these results show a key pathogenic and mechanistic role for neutrophil-derived EVs in a mouse model of COPD. Broadly, the in vivo model described herein could be leveraged to develop targeted therapies for severe lung disease.

Acute inhalation toxicity of aerosolized electrochemically generated solution of sodium hypochlorite

OBJECTIVE

The objective was to determine the inhalation toxicity of the electrochemically generated sodium hypochlorite solution after its single administration to laboratory animals in the form of a highly dispersed aerosol.

MATERIALS AND METHODS

The study has been conducted according to the OECD Test Guideline №403 'Acute Inhalation Toxicity.' Laboratory animals were exposed to inhalation of an aerosol containing 1.7 ± 0.13 mg/m³ of active chlorine. The hematological and biochemical parameters of the blood of experimental animals have been determined, as well as specific parameters: the activity of cathepsins B and L, catalase, and α1-antitrypsin. Histological study of the lungs of animals has been carried out.

RESULTS

During inhalation and 14 days after it, no death of the animals was observed; the behavior, appearance, and weight gain did not differ from the control group. There were no significant deviations in hematological parameters, except the decrease in the level of platelets. The biochemical study showed slight changes in the activity of alkaline phosphatase and aspartate aminotransferase on the 1st day after inhalation; these parameters returned to normal within 14 days of observation. Specific biochemical parameters did not show the development of oxidative stress. No specific histological pathologies of lung tissue have been found.

CONCLUSIONS

Thus, the studied electrochemically generated sodium hypochlorite solution under single inhalation exposure in aerosol form practically does not cause a toxic effect. The data obtained allow classifying such solution to the 4th (or even 5th - after additional studies) class of toxicity in accordance with Globally Harmonized System of Classification and Labeling of Chemicals.

Biomarkers in the clinical management of patients with atrial fibrillation and heart failure

Atrial fibrillation (AF) and heart failure (HF) are two cardiovascular diseases with an increasing prevalence worldwide. These conditions share common pathophysiologiesand frequently co-exit. In fact, the occurrence of either condition can 'cause' the development of the other, creating a new patient group that demands different management strategies to that if they occur in isolation. Regardless of the temproral association of the two conditions, their presence is linked with adverse cardiovascular outcomes, increased rate of hospitalizations, and increased economic burden on healthcare systems. The use of low-cost, easily accessible and applicable biomarkers may hasten the correct diagnosis and the effective treatment of AF and HF. Both AF and HF effect multiple physiological pathways and thus a great number of biomarkers can be measured that potentially give the clinician important diagnostic and prognostic information. These will then guide patient centred therapeutic management. The current biomarkers that offer potential for guiding therapy, focus on the physiological pathways of miRNA, myocardial stretch and injury, oxidative stress, inflammation, fibrosis, coagulation and renal impairment. Each of these has different utility in current clinincal practice.

7-Fluorosialyl Glycosides Are Hydrolysis Resistant but Readily Assembled by Sialyltransferases Providing Easy Access to More Metabolically Stable Glycoproteins

The maintenance of therapeutic glycoproteins within the circulatory system is associated, in large part, with the integrity of sialic acids as terminal sugars on the glycans. Glycoprotein desialylation, either by spontaneous cleavage or through host sialidases, leads to protein clearance, mainly through the liver. Thus, the installation of minimally modified sialic acids that are hydrolysis-resistant yet biologically equivalent should lead to increased circulatory half-lives and improved pharmacokinetic profiles. Here we describe the chemoenzymatic synthesis of CMP-sialic acid sugar donors bearing fluorine atoms at the 7-position, starting from the corresponding 4-deoxy-4-fluoro-N-acetylhexosamine precursors. For the derivative with natural stereochemistry we observe efficient glycosyl transfer by sialyltransferases, along with improved stability of the resultant 7-fluorosialosides toward spontaneous hydrolysis (3- to 5-fold) and toward cleavage by GH33 sialidases (40- to 250-fold). Taking advantage of the rapid transfer of 7-fluorosialic acid by sialyltransferases, we engineered the O-glycan of Interferon α-2b and the N-glycans of the therapeutic glycoprotein α1-antitrypsin. Studies of the uptake of the glyco-engineered α1-antitrypsin by HepG2 liver cells demonstrated the bioequivalence of 7-fluorosialic acid to sialic acid in suppressing interaction with liver cell lectins. In vivo pharmacokinetic studies reveal enhanced half-life of the protein decorated with 7-fluorosialic acid relative to unmodified sialic acid in the murine circulatory system. 7-Fluorosialylation therefore offers considerable promise as a means of prolonging circulatory half-lives of glycoproteins and may pave the way toward biobetters for therapeutic use.

Monocytes and Macrophages in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is a genetic condition characterised by low circulating levels of alpha-1 antitrypsin (AAT), a serine proteinase inhibitor. The most common deficiency variants are the S and Z mutations, which cause the accumulation of misfolded AAT in hepatocytes resulting in endoplasmic reticular stress and insufficient release of AAT into the circulation (<11μmol/L). This leads to liver disease, as well as an increased risk of emphysema due to unopposed proteolytic activity of neutrophil-derived serine proteinases in the lungs. AATD has been traditionally viewed as an inflammatory disorder caused directly by a proteinase-antiproteinase imbalance in the lung, but increasing evidence suggests that low AAT levels may affect other cellular functions. Recently, AAT polymers have been identified in both monocytes and macrophages from AATD patients and evidence is building that these cells may also play a role in the development of AATD lung disease. Alveolar macrophages are phagocytic cells that are important in the lung immune response but are also implicated in driving inflammation. This review explores the potential implications of monocyte and macrophage involvement in non-liver AAT synthesis and the pathophysiology of AATD lung disease.

Alpha-1 Antitrypsin Deficiency: Have We Got the Right Proteinase?

Alpha-1 antitrypsin deficiency (AATD) has traditionally been associated with the development of early onset panlobular emphysema thought to reflect the direct interstitial damage caused by neutrophil elastase. Since this enzyme is highly sensitive to irreversible inhibition by alpha-1 antitrypsin (AAT), the logic of intravenous augmentation therapy has remained unquestioned and efficacy is supported by both observational studies and formal clinical trials. However, evidence suggests that although AAT augmentation modulates the progression of emphysema, it only slows it down. This raises the issue of whether our long-held beliefs of the cause of the susceptibility to develop emphysema in deficient individuals are correct. There are several aspects of our understanding of the disease that might benefit from a radical departure from traditional thought. This review addresses these concepts and alternative pathways that may be central to progression of emphysema.

Neutrophil phenotypes in chronic lung disease

Introduction: Neutrophils are the most abundant inflammatory cells in the lungs of patients with chronic lung diseases, especially COPD, yet despite this, patients often experience repeated chest infections. Neutrophil function may be altered in disease, but the reasons are unclear. In chronic disease, sequential pro-inflammatory and pro-repair responses appear distorted. As understanding of neutrophil heterogeneity has expanded, it is suggested that different neutrophil phenotypes may impact on health and disease. Areas covered: In this review, the definition of cellular phenotype, the implication of neutrophil surface markers and functions in chronic lung disease and the complex influences of external, local and genetic factors on these changes are discussed. Literature was accessed up to the 19 July 2019 using: PubMed, US National Library of Medicine National Institutes of Health and the National Centre for Biotechnology Information. Expert opinion: As more is learned about neutrophils, the further we step from the classical view of neutrophils being unrefined killing machines to highly complex and finely tuned cells. Future therapeutics may aim to normalize neutrophil function, but to achieve this, knowledge of phenotypes in humans and how these relate to observed pathology and disease processes is required.

Family health history: underused for actionable risk assessment

Family health history (FHH) is the most useful means of assessing risk for common chronic diseases. The odds ratio for risk of developing disease with a positive FHH is frequently greater than 2, and actions can be taken to mitigate risk by adhering to screening guidelines, genetic counselling, genetic risk testing, and other screening methods. Challenges to the routine acquisition of FHH include constraints on provider time to collect data and the difficulty in accessing risk calculators. Disease-specific and broader risk assessment software platforms have been developed, many with clinical decision support and informatics interoperability, but few access patient information directly. Software that allows integration of FHH with the electronic medical record and clinical decision support capabilities has provided solutions to many of these challenges. Patient facing, electronic medical record, and web-enabled FHH platforms have been developed, and can provide greater identification of risk compared with conventional FHH ascertainment in primary care. FHH, along with cascade screening, can be an important component of population health management approaches to overall reduction of risk.

Activated PMN Exosomes: Pathogenic Entities Causing Matrix Destruction and Disease in the Lung

Here, we describe a novel pathogenic entity, the activated PMN (polymorphonuclear leukocyte, i.e., neutrophil)-derived exosome. These CD63+/CD66b+ nanovesicles acquire surface-bound neutrophil elastase (NE) during PMN degranulation, NE being oriented in a configuration resistant to α1-antitrypsin (α1AT). These exosomes bind and degrade extracellular matrix (ECM) via the integrin Mac-1 and NE, respectively, causing the hallmarks of chronic obstructive pulmonary disease (COPD). Due to both ECM targeting and α1AT resistance, exosomal NE is far more potent than free NE. Importantly, such PMN-derived exosomes exist in clinical specimens from subjects with COPD but not healthy controls and are capable of transferring a COPD-like phenotype from humans to mice in an NE-driven manner. Similar findings were observed for another neutrophil-driven disease of ECM remodeling (bronchopulmonary dysplasia [BPD]). These findings reveal an unappreciated role for exosomes in the pathogenesis of disorders of ECM homeostasis such as COPD and BPD, providing a critical mechanism for proteolytic damage.

Imbalance of NET and Alpha-1-Antitrypsin in Tuberculosis Patients Is Related With Hyper Inflammation and Severe Lung Tissue Damage

Background: Pulmonary tuberculosis (PTB) can lead to lung tissue damage (LTD) and compromise the pulmonary capacity of TB patients that evolve to severe PTB. The molecular mechanisms involved in LTD during anti-tuberculous treatment (ATT) remain poorly understood.

Methods and findings: We evaluated the role of neutrophil extracellular trap (NET) and the occurrence of LTD through chest radiographic images, the microbial load in sputum, and inflammatory serum profile (IL-12p40/p70, IL-8, IL-17A, IL-23, VEGF-A, MMP-1, and -8, galectin-3, citrunillated histone H3—cit-H3, alpha-1-antitrypsin—α1AT, C-reactive protein—CRP and albumin) in a cohort of 82 PTB patients before and after 60 days of ATT. Using univariate analysis, LTD was associated with neutrophilia and increase of several inflammatory proteins involved in the neutrophil-mediated response, being cit-H3 the more related to the event. In the multivariate analysis, neutrophilia and cit-H3 appear as directly related to LTD. The analysis of the ROC curve at day 60 presented AUC of 0.97 (95.0% CI 0.95–1). Interestingly, at day 0 of ATT, these biomarkers demonstrated fine relation with LTD showing an AUC 0.92 (95.0% CI 0.86–0.99). Despite of that, the same molecules have no impact in culture conversion during ATT.

Conclusions: Our data revealed that NETs may play a key role in the pathway responsible for non-specific inflammation and tissue destruction in PTB. High level of cit-H3 and low level of α1AT was observed in the serum of severe TB patients, suggesting a breakdown in the intrinsic control of NET-driven tissue damage. These data show a new insight to knowledge TB immunopathogenesis, the role of neutrophil and NET pathway. Likewise, we identified possible biomarkers to screening of PTB patients eligible to adjuvants therapies, as anti-inflammatories and alpha-1-antitrypsin.

Hematopoietic Stem/Progenitor Cell Dependent Participation of Innate Lymphoid Cells in Low-Intensity Sterile Inflammation

Hematopoietic stem/progenitor cells (HSPC) are characterized by their unique capacities of self-renewal and multi-differentiation potential. This second property makes them able to adapt their differentiation profile depending on the local environment they reach. Taking advantage of an animal model of peritonitis, induced by injection of the TLR-2 ligand, zymosan, we sought to study the relationship between bone marrow-derived hematopoietic stem/progenitor cells (BM-HSPCs) and innate lymphoid cells (ILCs) regarding their emergence and differentiation at the site of inflammation. Our results demonstrate that the strength of the inflammatory signals affects the capacity of BM-derived HSPCs to migrate and give rise in situ to ILCs. Both low- and high-dose of zymosan injections trigger the appearance of mature ILCs in the peritoneal cavity where the inflammation occurs. Herein, we show that only in low-dose injected mice, the recovered ILCs are dependent on an in situ differentiation of BM-derived HSPCs and/or ILC2 precursors (ILC2P) wherein high-dose, the stronger inflammatory environment seems to be able to induce the emergence of ILCs independently of BM-derived HSPCs. We suggest that a relationship between HSPCs and ILCs seems to be affected by the strength of the inflammatory stimuli opening new perspectives in the manipulation of these early hematopoietic cells.

Dipeptidyl Peptidase 1 Inhibitor AZD7986 Induces a Sustained, Exposure-Dependent Reduction in Neutrophil Elastase Activity in Healthy Subjects

Neutrophil serine proteases (NSPs), such as neutrophil elastase (NE), are activated by dipeptidyl peptidase 1 (DPP1) during neutrophil maturation. High NSP levels can be detrimental, particularly in lung tissue, and inhibition of NSPs is therefore an interesting therapeutic opportunity in multiple lung diseases, including chronic obstructive pulmonary disease (COPD) and bronchiectasis. We conducted a randomized, placebo‐controlled, first‐in‐human study to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of single and multiple oral doses of the DPP1 inhibitor AZD7986 in healthy subjects. Pharmacokinetic and pharmacodynamic data were analyzed using nonlinear mixed effects modeling and showed that AZD7986 inhibits whole blood NE activity in an exposure‐dependent, indirect manner—consistent with in vitro and preclinical predictions. Several dose‐dependent, possibly DPP1‐related, nonserious skin findings were observed, but these were not considered to prevent further clinical development. Overall, the study results provided confidence to progress AZD7986 to phase II and supported selection of a clinically relevant dose.

The Challenges of Precision Medicine in COPD

Pheno-/endotyping chronic obstructive pulmonary disease (COPD) is really important because it provides patients with precise and personalized medicine. The central concept of precision medicine is to take individual variability into account when making management decisions. Precision medicine should ensure that patients get the right treatment at the right dose at the right time, with minimum harmful consequences and maximum efficacy. Ideally, we should search for genetic and molecular biomarker-based profiles. Given the clinical complexity of COPD, it seems likely that a panel of several biomarkers will be required to characterize pathogenetic factors and their course over time. The need for biomarkers to guide the clinical care of individuals with COPD and to enhance the possibilities of success in drug development is clear and urgent, but biomarker development is tremendously challenging and expensive, and translation of research efforts to date has been largely ineffective. Furthermore, the development of personalized treatments will require a much more detailed understanding of the clinical and biological heterogeneity of COPD. Therefore, we are still far from being able to apply precision medicine in COPD and the treatable traits and FEV₁-free approaches are attempts to precision medicine in COPD that must be considered still quite unsophisticated.

Matrix metalloproteinases in emphysema

Several studies have implicated a causative role for specific matrix metalloproteinases (MMPs) in the development and progression of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) and its severe sequela, emphysema. However, the precise function of any given MMP in emphysema remains an unanswered question. Emphysema results from the degradation of alveolar elastin - among other possible mechanisms - a process that is often thought to be caused by elastolytic proteinases made by macrophages. In this article, we discuss the data suggesting, supporting, or refuting causative roles of macrophage-derived MMPs, with a focus on MMPs-7, -9, -10, -12, and 28, in both the human disease and mouse models of emphysema. Findings from experimental models suggest that some MMPs, such as MMP-12, may directly breakdown elastin, whereas others, particularly MMP-10 and MMP-28, promote the development of emphysema by influencing the proteolytic and inflammatory activities of macrophages.

Neutrophil Fates in Bronchiectasis and Alpha-1 Antitrypsin Deficiency

The neutrophil is a powerful cellular defender of the vulnerable interface between the environment and pulmonary tissues. This cell's potent weapons are carefully calibrated in the healthy state to maximize effectiveness in fighting pathogens while minimizing tissue damage and allowing for repair of what damage does occur. The three related chronic airway disorders of cystic fibrosis, non-cystic fibrosis bronchiectasis, and alpha-1 antitrypsin deficiency all demonstrate significant derangements of this homeostatic system that result in their respective pathologies. An important shared feature among them is the inefficient resolution of chronic inflammation that serves as a central means for neutrophil-driven lung damage resulting in disease progression. Examining the commonalities and divergences between these diseases in the light of their immunopathology is informative and may help guide us toward future therapeutics designed to modulate the neutrophil's interplay with the pulmonary environment.

Alpha-1 Antitrypsin Deficiency: Phenotypes and Quality of Life

Alpha-1 antitrypsin deficiency (AATD) is a recognized genetic cause of rapidly progressive loss of lung function conventionally assessed by the decline in FEV1. However, there is less information concerning other physiological measures and the impact on quality of life. Data derived predominantly from the UK national registry show that AATD presents with various physiological phenotypes with differing clinical impact and progression. In general, the decline in quality of life is surprisingly slow despite rapid loss of lung function, which may reflect the benefits of centralized services for patients with AATD. Use of the new GOLD classification identifies patient characteristics that relate to mortality and disparate symptomatology despite similar spirometric impairment.

Diagnosing alpha-1 antitrypsin deficiency: the first step in precision medicine

Severe alpha-1 antitrypsin (AAT) deficiency is one of the most common serious genetic diseases in adults of European descent. Individuals with AAT deficiency have a greatly increased risk for emphysema and liver disease. Other manifestations include bronchiectasis, necrotizing panniculitis and granulomatosis with polyangiitis. Despite the frequency and potential severity, AAT deficiency remains under-recognized, and there is often a delay in diagnosis. This review will focus on three recent updates that should serve to encourage testing and diagnosis of AAT deficiency: first, the publication of a randomized clinical trial demonstrating the efficacy of intravenous augmentation therapy in slowing the progression of emphysema in AAT deficiency; second, the mounting evidence showing an increased risk of lung disease in heterozygous PI MZ genotype carriers; last, the recent publication of a clinical practice guideline, outlining diagnosis and management. Though it has been recognized for more than fifty years, AAT deficiency exemplifies the modern paradigm of precision medicine, with a diagnostic test that identifies a genetic subtype of a heterogeneous disease, leading to a targeted treatment.

Evaluation of Alpha-1 Antitrypsin Levels and SERPINA1 Gene Polymorphisms in Sickle Cell Disease

Alpha-1 antitrypsin (AAT) is an inhibitor of neutrophil elastase and a member of the serine proteinase inhibitor (serpin) superfamily, and little is known about its activity in sickle cell disease (SCD). We hypothesize that AAT may undergo changes in SCD because of the high oxidative stress and inflammation associated with the disease. We have found high AAT levels in SCD patients compared to controls, while mutant genotypes of SERPINA1 gene had decreased AAT levels, in both groups. AAT showed negative correlation with red blood cells, hemoglobin (Hb), hematocrit, high-density lipoprotein cholesterol, urea, creatinine, and albumin and was positively correlated with mean corpuscular Hb concentration, white blood cells, neutrophils, Hb S, bilirubin, lactate dehydrogenase, ferritin, and C-reactive protein. Patients with higher levels of AAT had more infection episodes (OR = 1.71, CI: 1.05–2.65, p = 0.02), gallstones (OR = 1.75, CI: 1.03–2.97, p = 0.02), and had more blood transfusions (OR = 2.35, CI: 1.51–3.65, p = 0.0001). Our data on AAT association with laboratory indices of hemolysis and inflammation suggest that it may be positively associated with SCD severity; the negative correlations with renal parameters suggest a cytoprotective mechanism in SCD patients. In summary, AAT may need to be included in studies related to SCD and in the discussion of further therapeutic strategies.

Survival after lung transplantation in recipients with alpha-1-antitrypsin deficiency compared to other forms of chronic obstructive pulmonary disease: a national cohort study

Alpha-1-antitrypsin deficiency (AATD) is grouped with chronic obstructive pulmonary disease (COPD); however, this may not be appropriate. This study assessed whether AATD confers a different prognosis than COPD following lung transplantation. We employed the United Network for Organ Sharing (UNOS) database, grouping patients by diagnoses of AATD or COPD. Kaplan-Meier methods and Cox modeling were performed to determine the association of diagnosis and overall survival. Of 9569 patients, 1394 (14.6%) had a diagnosis of AATD. Patients with AATD who received a single-lung transplant had reduced 1-year survival [adjusted hazard ratio (AHR): 1.68, 95% CI: 1.26, 2.23]. Among patients who received a bilateral lung transplant, there was no significant difference in survival by diagnosis (AHR for AATD as compared to COPD: 0.96, 95% CI: 0.82, 1.12). After the implementation of the lung allocation score (LAS), there was no significant difference in survival among patients who received a single (AHR: 1.15, 95% CI: 0.69, 1.95) or bilateral (AHR: 0.99, 95% CI: 0.73, 1.34) lung transplant by diagnosis. Lung transplantation is increasingly employed in the care of the patient with COPD. Although recipients undergoing LTX for AATD are at increased risk of both acute rejection and airway dehiscence post-transplant, in the post-LAS era, survival rates are similar for recipients with AATD in comparison with COPD.

Serum Proteins Associated with Emphysema Progression in Severe Alpha-1 Antitrypsin Deficiency

Computed tomography (CT) lung density is an accepted biomarker for emphysema in alpha-1 antitrypsin deficiency (AATD), although concerns for radiation exposure limit its longitudinal use. Serum proteins associated with emphysema, particularly in early disease, may provide additional pathogenic insights. We investigated whether distinct proteomic signatures characterize the presence and progression of emphysema in individuals with severe AATD and normal forced expiratory volume in 1 second (FEV₁). QUANTitative lung CT UnMasking emphysema progression in AATD (QUANTUM-1) is a multicenter, prospective 3-year study of 49 adults with severe AATD and FEV₁ post-bronchodilator values (Post-BD) ≥ 80% predicted. All participants received chest CT, serial spirometry, and contributed to the serum biobank. Volumetric imaging display and analysis (VIDA) software defined the baseline 15^th percentile density (PD15) which was indexed to CT-derived total lung capacity (TLC). We measured 317 proteins using a multiplexed immunoassay (Myriad Discovery MAP^® panel) in 31 individuals with a complete dataset. We analyzed associations between initial PD15/TLC, PD15/TLC annual decline, body mass index (BMI), and protein levels using Pearson's product moment correlation. C-reactive protein (CRP), adipocyte fatty acid-binding protein (AFBP), leptin, and tissue plasminogen activator (tPA) were found to be associated with baseline emphysema and all but leptin were associated with emphysema progression after adjustments were made for age and sex. All 4 proteins were associated with BMI after further adjustment for multiple comparisons was made. The relationship between these proteins and BMI, and further validation of these findings in replicative cohorts require additional studies.

Liver Involvement in Patients With PiZZ-Emphysema, Candidates for Lung Transplantation

Information about the prevalence and nature of liver disorders in adults with alpha1-antitrypsin deficiency is scarce. At our center, systematic liver biopsy screening is part of the evaluation before lung transplantation (LT) in the emphysema patients with the PiZZ phenotype. Our aim was to report our experience with this prospective screening. Clinical, liver function, and imaging parameters as well as liver histology data were analyzed for 23 consecutive adult patients with PiZZ severe emphysema referred to our center for consideration of LT from 2006 to 2014. Overall 20 (87%) featured chronic liver disease characterized by a chronic inflammation and/or a significant portal fibrosis on histology. Two of the 23 patients (8.7%) had septal fibrosis according to the Metavir and Ishak scores and met our definition of severe chronic liver disease. They were both clinically asymptomatic with normal liver function tests. On abdominal ultrasonography, the liver appeared normal in one patient and with abnormal contours in the other. Our data indicate that in adults with PiZZ-related emphysema being evaluated for LT, most patients had some histologic involvement. The prevalence of severe liver dysfunction is <10%.

Pathophysiology of Alpha-1 Antitrypsin Lung Disease

Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by low serum levels of alpha-1 antitrypsin (AAT). Loss of AAT disrupts the protease-antiprotease balance in the lungs, allowing proteases, specifically neutrophil elastase, to act uninhibited and destroy lung matrix and alveolar structures. Destruction of these lung structures classically leads to an increased risk of developing emphysema and chronic obstructive pulmonary disease (COPD), especially in individuals with a smoking history. It is estimated that 3.4 million people worldwide have AATD. However, AATD is considered to be significantly underdiagnosed and underrecognized by clinicians. Contributing factors to the diagnostic delay of approximately 5.6 years are: inadequate awareness by healthcare providers, failure to implement recommendations from the American Thoracic Society/European Respiratory Society, and the belief that AATD testing is not warranted. Diagnosis can be attained using qualitative or quantitative laboratory testing. The only FDA approved treatment for AATD is augmentation therapy, although classically symptoms have been treated similarly to those of COPD. Future goals of AATD treatment are to use gene therapy using vector systems to produce therapeutic levels of AAT in the lungs without causing a systemic inflammatory response.

Expression and Purification of Active Recombinant Human Alpha-1 Antitrypsin (AAT) from Escherichia coli

Well-established genetic manipulation procedures along with a fast doubling time, the ability to grow in inexpensive media, and easy scaleup make Escherichia coli (E. coli) a preferred recombinant protein expression platform. Human alpha-1 antitrypsin (AAT) and other serpins are easily expressed in E. coli despite their metastability and complicated topology. Serpins can be produced as soluble proteins or aggregates in inclusion bodies, and both forms can be purified to homogeneity. In this chapter, we describe an ion-exchange chromatography-based protocol that we have developed involving the use of two anion-exchange columns to purify untagged human AAT from E. coli. We also outline methods that can be used to determine the inhibitory activity of both AAT in cell lysates and purified AAT. Our protocol for the purification of bacterially expressed AAT yields pure and active protein at 6-7 mg/l culture.

A Library of Rare α1-Antitrypsin (AAT) Variant Phenotypes to Aid in the Diagnosis of AAT Deficiency

OBJECTIVES

α1-Antitrypsin (AAT) deficiency is a hereditary disorder due to defective production of the serine protease inhibitor, AAT, which can cause lung and liver diseases. Severity of disease depends particularly on the phenotypic representation of AAT variants in the patient.

METHODS

In this study, we present determination of seven common and nine rare variant phenotypes of AAT using pediatric samples collected in Texas Children's Hospital to address the knowledge gap in the identification of rare variants. We tested 16 different AAT variants that had been stored in a -80 °C freezer over the years to add to the reference library of AAT variants. The gold-standard isoelectric focusing electrophoresis method was used for analysis and interpretation of AAT variants. Each variant was inspected visually by comparing multiple bands, unique to phenotypic identity, with a previously identified pattern.

RESULTS

Seven common M, S, and Z variants were identified as M1M1, M2M2, M1M2, MS, SS, SZ, and ZZ. Nine rare variants were identified as FM, FS, FZ, PM, XM, YM, IM, TS, and EP. These were interpreted independently and in a blinded manner by an experienced technologist and two clinical chemists from two different institutions.

CONCLUSIONS

Our results add to the reference library to identify the rare variant phenotypes of AAT protein. This report will guide clinical laboratories for proper assessment of rare variants and in turn contribute to accurate diagnosis and management of AAT deficiency.

Evaluation of Individuals at Risk for COPD: Beyond the Scope of the Global Initiative for Chronic Obstructive Lung Disease

The Global initiative for chronic Obstructive Lung Disease (GOLD) Strategy is a valuable tool for clinicians in the diagnosis and management of patients with established chronic obstructive pulmonary disease (COPD). However, there are no recommendations for the evaluation of individuals, exposed to risk factors, who are most likely to develop COPD. Consequently, it is necessary to consider all of the factors that may play a role in the pathogenesis of COPD: genetic factors, gender, socioeconomic status, disadvantageous factors in childhood, lung diseases and exposure to risk factors such as smoking, biomass fuel smoke, occupational hazards and air pollution. Along with the clinical assessment, periodic spirometry should be performed to evaluate lung function and make possible early detection of individuals who will develop the disease through the rate of forced expiratory volume in 1 second (FEV₁) decline. The first spirometry, periodicity, and clinically significant decline in FEV₁ will encompass the cornerstones of clinical follow up. This approach allows the implementation of important interventions in order to help individuals to cease contact with risk factors and prevent progressive respiratory impairment with the consequent deterioration of quality of life and increased morbidity and mortality.

Are Asthma and COPD a Continuum of the Same Disease?

Asthma and chronic obstructive pulmonary disease (COPD) are common heterogeneous diseases with significant impact on morbidity, mortality, and health care costs. In most of the cases, the main features and pathophysiology differ substantially between both asthma and COPD, which allows differentiating both entities and providing appropriate treatment. The recognition of a subgroup of patients who present clinically with features of both conditions, asthma chronic obstructive pulmonary disease overlap syndrome, has reignited the question of whether asthma and COPD are different manifestations of the same disease or unique processes, the so-called Dutch hypothesis versus British hypothesis controversy. There is enough heterogeneity in the clinical and mechanistic profiles of these 3 diseases, and subsets of these 3 diseases, to suggest that a new approach relying on the concept of endotypes of obstructive airways disease may be more useful. This characterization has provided the basis for opening new areas of research that may eventually lead to the development of new targeted drugs. This review focuses on the current knowledge of asthma, COPD, and asthma chronic obstructive pulmonary disease overlap syndrome phenotypes with emphasis on mechanisms of disease and how these may define endotypes, providing a more rational approach to research and clinical care.

Corticosteroid-binding globulin cleavage is paradoxically reduced in alpha-1 antitrypsin deficiency: Implications for cortisol homeostasis

High-affinity corticosteroid-binding globulin (haCBG) is cleaved by neutrophil elastase (NE) resulting in permanent transition to the low cortisol-binding affinity form (laCBG), thereby increasing cortisol availability at inflammatory sites. Alpha-1 antitrypsin (AAT) is the major inhibitor of NE. AAT deficiency (AATD) predisposes patients to early-onset emphysema due to increased proteolytic destruction from the inherent proteinase-antiproteinase imbalance. We hypothesized that AATD may result in increased CBG cleavage in vivo. We collected demographic data and blood samples from 10 patients with AATD and 28 healthy controls measuring total CBG and haCBG levels by parallel in-house ELISAs, as well as AAT, total and free cortisol levels. haCBG was higher (median [range]); 329 [210-551] vs. 250 [175-365] nmol/L; P<0.005, and laCBG lower; 174 [68-229] vs. 220 [119-348] nmol/L; P=0.016 in the AATD group, compared with controls. The ratio of haCBG:total CBG was also higher in AATD; 72 [53-83] vs. 54 [41-72] %; P=0.0001). There was a negative correlation between haCBG:total CBG and AAT levels (P<0.05, R=-0.64). Paradoxically, proteolytic cleavage of CBG was reduced in AATD, despite the recognized increase in NE activity. This implies that NE activity is not the mechanism for systemic CBG cleavage in basal, low inflammatory conditions. Relatively low levels of laCBG may have implications for cortisol action in AATD.

α1-Antitrypsin Combines with Plasma Fatty Acids and Induces Angiopoietin-like Protein 4 Expression

α1-Antitrypsin (A1AT) purified from human plasma upregulates expression and release of angiopoietin-like protein 4 (Angptl4) in adherent human blood monocytes and in human lung microvascular endothelial cells, providing a mechanism for the broad immune-regulatory properties of A1AT independent of its antiprotease activity. In this study, we demonstrate that A1AT (Prolastin), a potent inducer of Angptl4, contains significant quantities of the fatty acids (FA) linoleic acid (C18:2) and oleic acid (C18:1). However, only trace amounts of FAs were present in preparations that failed to increase Angplt4 expression, for example, A1AT (Zemaira) or M-type A1AT purified by affinity chromatography. FA pull-down assays with Western blot analysis revealed a FA-binding ability of A1AT. In human blood-adherent monocytes, A1AT-FA conjugates upregulated expression of Angptl4 (54.9-fold, p < 0.001), FA-binding protein 4 (FABP4) (11.4-fold, p < 0.001), and, to a lesser degree, FA translocase (CD36) (3.1-fold, p < 0.001) relative to A1AT devoid of FA (A1AT-0). These latter effects of A1AT-FA were blocked by inhibitors of peroxisome proliferator-activated receptor (PPAR) β/δ (ST247) and PPARγ (GW9662). When compared with controls, cell pretreatment with ST247 diminished the effect of A1AT-LA on Angptl4 mRNA (11.6- versus 4.1-fold, p < 0.001) and FABP4 mRNA (5.4- versus 2.8-fold, p < 0.001). Similarly, preincubation of cells with GW9662 inhibited inducing effect of A1AT-LA on Angptl4 mRNA (by 2-fold, p < 0.001) and FABP4 mRNA (by 3-fold, p < 0.001). Thus, A1AT binds to FA, and it is this form of A1AT that induces Angptl4 and FABP4 expression via a PPAR-dependent pathway. These findings provide a mechanism for the unexplored area of A1AT biology independent of its antiprotease properties.

Transition of gastroenterological patients from paediatric to adult care: A position statement by the Italian Societies of Gastroenterology

In 2013, four Italian Gastroenterological Societies (the Italian Society of Paediatric Gastroenterology, Hepatology and Nutrition, the Italian Society of Hospital Gastroenterologists and Endoscopists, the Italian Society of Endoscopy, and the Italian Society of Gastroenterology) formed a joint panel of experts with the aim of preparing an official statement on transition medicine in Gastroenterology. The transition of adolescents from paediatric to adult care is a crucial moment in managing chronic diseases such as celiac disease, inflammatory bowel disease, liver disease and liver transplantation. Improved medical treatment and availability of new drugs and surgical techniques have improved the prognosis of many paediatric disorders, prolonging survival, thus making the transition to adulthood possible and necessary. An inappropriate transition or the incomplete transmission of data from the paediatrician to the adult Gastroenterologist can dramatically decrease compliance to treatment and prognosis of a young patient, particularly in the case of severe disorders. For these reasons, the Italian gastroenterological societies decided to develop an official shared transition protocol. The resulting document discusses the factors influencing the transition process and highlights the main points to accomplish to optimize compliance and prognosis of gastroenterological patients during the difficult transition from childhood to adolescence and adulthood.

Neutrophil elastase inhibitors for the treatment of (cardio)pulmonary diseases: Into clinical testing with pre-adaptive pharmacophores

Alpha-1 antitrypsin deficiency is linked with an increased risk of suffering from lung emphysema. This discovery from the 1960s led to the development of the protease-antiprotease (im)balance hypothesis: Overshooting protease concentrations, especially high levels of elastase were deemed to have an destructive effect on lung tissue. Consequently, it was postulated that efficient elastase inhibitors could alleviate the situation in patients. However, despite intensive drug discovery efforts, even five decades later, no neutrophil elastase inhibitors are available for a disease-modifying treatment of (cardio)pulmonary diseases such as chronic obstructive pulmonary disease. Here, we critically review the attempts to develop effective human neutrophil elastase inhibitors while strongly focussing on recent developments. On purpose and with perspective distortion we focus on recent developments. One aim of this review is to classify the known HNE inhibitors into several generations, according to their binding modes. In general, there seem to be three major challenges in the development of suitable elastase inhibitors: (1) assuring sufficient potency, (2) securing selectivity, and (3) achieving metabolic stability especially under pathophysiological conditions. Impressive achievements have been made since 2001 with the identification of potent nonreactive, reversible small molecule inhibitors. The most modern inhibitors bind HNE via an induced fit with a frozen bioactive conformation that leads to a significant boost in potency, selectivity, and stability ('pre-adaptive pharmacophores'). These 5th generation inhibitors might succeed in re-establishing the protease-antiprotease balance in patients for the first time.

Neutrophil proteases alter the interleukin-22-receptor-dependent lung antimicrobial defence

Chronic obstructive pulmonary disease (COPD) is punctuated by episodes of infection-driven acute exacerbations. Despite the life-threatening nature of these exacerbations, the underlying mechanisms remain unclear, although a high number of neutrophils in the lungs of COPD patients is known to correlate with poor prognosis. Interleukin (IL)-22 is a cytokine that plays a pivotal role in lung antimicrobial defence and tissue protection. We hypothesised that neutrophils secrete proteases that may have adverse effects in COPD, by altering the IL-22 receptor (IL-22R)-dependent signalling.Using in vitro and in vivo approaches as well as reverse transcriptase quantitative PCR, flow cytometry and/or Western blotting techniques, we first showed that pathogens such as the influenza virus promote IL-22R expression in human bronchial epithelial cells, whereas Pseudomonas aeruginosa, bacterial lipopolysaccharide or cigarette smoke do not. Most importantly, neutrophil proteases cleave IL-22R and impair IL-22-dependent immune signalling and expression of antimicrobial effectors such as β-defensin-2. This proteolysis resulted in the release of a soluble fragment of IL-22R, which was detectable both in cellular and animal models as well as in sputa from COPD patients with acute exacerbations.Hence, our study reveals an unsuspected regulation by the proteolytic action of neutrophil enzymes of IL-22-dependent lung host response. This process probably enhances pathogen replication, and ultimately COPD exacerbations.

Characteristics of Chronic Obstructive Pulmonary Disease (COPD) Patients Reporting Alpha-1 Antitrypsin Deficiency in the WebMD Lung Health Check Database

Objectives: This study compared characteristics of chronic obstructive pulmonary disease (COPD) among patients with and without alpha-1 antitrypsin deficiency (A1AD). Methods: Data from WebMD's Lung Disease Health Check was analyzed for participants who self-reported a COPD diagnosis (N=177,865) and whether or not they had an A1AD diagnosis (based on a positive response to the question "Do you have alpha-1 antitrypsin deficiency?"). We used regression modeling to determine the relation between A1AD status and demographic characteristics, symptoms, lung function, quality of life, comorbidities, and smoking habits. Results: Out of 177,865 participants who reported a COPD diagnosis, 1,619 (0.92%) also reported an A1AD diagnosis. When compared to the total COPD population, those with A1AD were less likely to be female (odds ratio [OR]=0.68, 95% confidence interval [CI] 0.61, 0.75) or current smokers (OR 0.72, 95% CI 0.62, 0.83), and more likely to know their lung function value (OR=3.44, 95% CI 3.07, 3.87). With regard to symptoms, those with A1AD were less likely to report wheezing (OR=0.82, 95% CI 0.75, 0.91) and chronic cough (OR=0.81, 95% CI 0.73, 0.89) and more likely to report tightness in the chest (OR= 1.19, 95% CI 1.08, 1.32). Overall, A1AD participants had a lower quality of life with a higher proportion reporting severe impairment in work life (OR=1.55, 95% CI 1.39, 1.7), home life (OR=1.40, 95% CI 1.26, 1.56), and personal relationships (OR=1.48, 95% CI 1.32, 1.65). Conclusions: COPD patients with A1AD report significantly worse quality of life relative to the non-A1AD COPD population.

Characteristics of Chronic Obstructive Pulmonary Disease (COPD) Patients Reporting Alpha-1 Antitrypsin Deficiency in the WebMD Lung Health Check Database

Objectives: This study compared characteristics of chronic obstructive pulmonary disease (COPD) among patients with and without alpha-1 antitrypsin deficiency (A1AD). Methods: Data from WebMD's Lung Disease Health Check was analyzed for participants who self-reported a COPD diagnosis (N=177,865) and whether or not they had an A1AD diagnosis (based on a positive response to the question "Do you have alpha-1 antitrypsin deficiency?"). We used regression modeling to determine the relation between A1AD status and demographic characteristics, symptoms, lung function, quality of life, comorbidities, and smoking habits. Results: Out of 177,865 participants who reported a COPD diagnosis, 1,619 (0.92%) also reported an A1AD diagnosis. When compared to the total COPD population, those with A1AD were less likely to be female (odds ratio [OR]=0.68, 95% confidence interval [CI] 0.61, 0.75) or current smokers (OR 0.72, 95% CI 0.62, 0.83), and more likely to know their lung function value (OR=3.44, 95% CI 3.07, 3.87). With regard to symptoms, those with A1AD were less likely to report wheezing (OR=0.82, 95% CI 0.75, 0.91) and chronic cough (OR=0.81, 95% CI 0.73, 0.89) and more likely to report tightness in the chest (OR= 1.19, 95% CI 1.08, 1.32). Overall, A1AD participants had a lower quality of life with a higher proportion reporting severe impairment in work life (OR=1.55, 95% CI 1.39, 1.7), home life (OR=1.40, 95% CI 1.26, 1.56), and personal relationships (OR=1.48, 95% CI 1.32, 1.65). Conclusions: COPD patients with A1AD report significantly worse quality of life relative to the non-A1AD COPD population.

Innate immune activation by tissue injury and cell death in the setting of hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) with donor lymphocyte infusion is the mainstay of treatment for many types of hematological malignancies, but the therapeutic effect and prevention of relapse is complicated by donor T-cell recognition and attack of host tissue in a process known as graft-versus-host disease (GvHD). Cytotoxic myeloablative conditioning regimens used prior to Allo-HSCT result in the release of endogenous innate immune activators that are increasingly recognized for their role in creating a pro-inflammatory milieu. This increased inflammatory state promotes allogeneic T-cell activation and the induction and perpetuation of GvHD. Here, we review the processes of cellular response to injury and cell death that are relevant following Allo-HSCT and present the current evidence for a causative role of a variety of endogenous innate immune activators in the mediation of sterile inflammation following Allo-HSCT. Finally, we discuss the potential therapeutic strategies that target the endogenous pathways of innate immune activation to decrease the incidence and severity of GvHD following Allo-HSCT.