Disease associations in alpha-1-antitrypsin deficiency

Prevalence of Cardiovascular Disease and Rate of Major Adverse Cardiovascular Events in Severe Alpha-1 Antitrypsin Deficiency COPD

Aim

Alpha-1 antitrypsin deficiency is an autosomal co-dominant condition that predisposes individuals to early-onset emphysema. As with COPD, AATD-COPD is associated with pulmonary exacerbations, which impacts on overall mortality and quality of life. Though there is evidence that COPD is associated with a higher prevalence of cardiovascular disease and major adverse cardiovascular events (MACE), it is unclear if this is true for patients with AATD-COPD.

Methods

Prevalence of cardiovascular disease was determined in two separate severe AATD cohorts: AlphaNet, USA and the Birmingham AATD registry, UK. All patients had preexisting lung disease. Cardiovascular disease was defined as presence of any of the following: heart failure, ischaemic heart disease, atrial fibrillation, stroke, and myocardial infarction. A Cox proportional hazards model was used to assess the impact of prior cardiovascular disease and frequent exacerbator phenotype on risk of future MACE.

Results

Out of 3493 patients with severe AATD, 14.7% had prior cardiovascular disease, including stroke (2.3%), myocardial infarction (2.2%), and heart failure (2.5%). Frequent exacerbators were more likely to have preexisting cardiovascular disease compared with those with one or no exacerbations in the preceding year (63% vs 44.8%, p = 0.001). There was increased risk of future MACE in frequent exacerbators (HR 1.85, 95% CI 1.24 to 2.75), former and current smokers (HR 1.80, 95% CI 1.07 to 3.02, p = 0.026, and HR 4.04, 95% CI 1.44 to 11.32, p = 0.008, respectively), and those with prior cardiovascular disease (HR 3.81, 95% CI 2.60 to 5.58, p < 0.001).

Conclusion

In severe AATD-COPD, MACE are associated with an increased exacerbation frequency, previous cardiovascular disease, and a history of smoking.

Altered Serum Alpha1-Antitrypsin Protease Inhibition before and after Clinical Hematopoietic Stem Cell Transplantation: Association with Risk for Non-Relapse Mortality

α1-Antitrypsin (AAT), an acute-phase reactant not unsimilar to C-reactive protein (CRP), is a serine protease inhibitor that harbors tissue-protective and immunomodulatory attributes. Its concentrations appropriately increase during conditions of extensive tissue injury, and it induces immune tolerance, in part, by inhibiting the enzymatic activity of the inflammatory serine protease, proteinase 3 (PR3). Typically administered to patients with genetic AAT deficiency, AAT treatment was recently shown to improve outcomes in patients with steroid-refractory graft-versus-host disease (GVHD). GVHD represents a grave outcome of allogeneic hematopoietic stem cell transplantation (HSCT), a potentially curative intervention for hematological diseases. The procedure requires radio/chemotherapy conditioning of the prospective marrow recipient, a cytotoxic process that causes vast tissue injury and, in some formats, interferes with liver production of AAT. To date, changes in the functional profile of AAT during allogeneic HSCT, and during the cytotoxic intervention that precedes HSCT, are unknown. The present study followed 53 patients scheduled for allogeneic HSCT (trial registration NCT03188601). Serum samples were tested before and after HSCT for AAT and CRP levels and for intrinsic anti-proteolytic activity. The ex vivo response to clinical-grade AAT was tested on circulating patient leukocytes and on a human epithelial cell line treated with patient sera in a gap closure assay. According to the ex vivo experiments, circulating leukocytes responded to AAT with a favorable immune-regulated profile, and epithelial gap closure was enhanced by AAT in sera from GVHD-free patients but not in sera from patients who developed GVHD. According to serum collected prior to HSCT, non-relapse mortality was reliably predicted by combining three components: AAT and CRP levels and serum anti-proteolytic activity. Taken together, HSCT outcomes are significantly affected by the anti-proteolytic function of circulating AAT, supporting early AAT augmentation therapy for allogeneic HSCT patients.

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

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

Does Genetic Predisposition Contribute to the Exacerbation of COVID-19 Symptoms in Individuals with Comorbidities and Explain the Huge Mortality Disparity between the East and the West?

The elderly and patients with several comorbidities experience more severe cases of coronavirus disease 2019 (COVID-19) than healthy patients without underlying medical conditions. However, it is unclear why these people are prone to developing alveolar pneumonia, rapid exacerbations, and death. Therefore, we hypothesized that people with comorbidities may have a genetic predisposition that makes them more vulnerable to various factors; for example, they are likely to become more severely ill when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To test this hypothesis, we searched the literature extensively. Polymorphisms of genes, such as those that encode angiotensin-converting enzyme 1 (ACE1), have been associated with numerous comorbidities, such as cardiovascular disease, hypertension, diabetes, chronic kidney disease, and obesity, and there are potential mechanisms to explain these associations (e.g., DD-type carriers have greater ACE1 activity, and patients with a genetic alpha-1 anti-trypsin (AAT) deficiency lack control over inflammatory mediators). Since comorbidities are associated with chronic inflammation and are closely related to the renin–angiotensin–aldosterone system (RAAS), these individuals may already have a mild ACE1/ACE2 imbalance before viral infection, which increases their risk for developing severe cases of COVID-19. However, there is still much debate about the association between ACE1 D/I polymorphism and comorbidities. The best explanation for this discrepancy could be that the D allele and DD subtypes are associated with comorbidities, but the DD genotype alone does not have an exceptionally large effect. This is also expected since the ACE1 D/I polymorphism is only an intron marker. We also discuss how polymorphisms of AAT and other genes are involved in comorbidities and the severity of SARS-CoV-2 infection. Presumably, a combination of multiple genes and non-genetic factors is involved in the establishment of comorbidities and aggravation of COVID-19.

Respiratory Tract Manifestations of Inflammatory Bowel Disease

Inflammatory bowel disease can manifest in many extraintestinal organ systems. The most frequently involved extraintestinal locations include the mucocutaneous, hepatobiliary, and ocular organ systems. The respiratory tract is less commonly involved and is therefore frequently overlooked. Consequently, it is believed that involvement of the respiratory tract in patients with inflammatory bowel disease is underreported. The pathogenesis is thought to be multifactorial, involving the common embryologic origin shared by the respiratory and luminal digestive tract, molecular mimicry, and immunologic interactions leading to immune-complex deposition in affected tissue. The spectrum of manifestations of the respiratory tract related to inflammatory bowel disease is broad. It not only includes direct involvement of the respiratory tract (ie, airways, interstitium, and pleura) but also can result as a consequence of systemic involvement such as in thromboembolic events. In addition, it may also be related to other conditions that affect the respiratory tract such as sarcoidosis and alpha-1 antitrypsin deficiency. Though some conditions related to respiratory tract involvement might be subclinical, others may have life-threatening consequences. It is critical to approach patients with suspected inflammatory bowel disease-related respiratory tract involvement in concert with pulmonology, infectious diseases, and any other pertinent experts, as treatments may require a multidisciplinary overlap of measures. Therefore, it is of paramount importance for the clinician to be aware of the array of respiratory tract manifestations of patients with inflammatory bowel disease, in addition to the possible spectrum of therapeutic measures.

Alpha-1 antitrypsin deficiency and recombinant protein sources with focus on plant sources: Updates, challenges and perspectives

Alpha-1 antitrypsin deficiency (A1ATD) is an autosomal recessive disease characterized by low plasma levels of A1AT, a serine protease inhibitor representing the most abundant circulating antiprotease normally present at plasma levels of 1-2 g/L. The dominant clinical manifestations include predispositions to early onset emphysema due to protease/antiprotease imbalance in distal lung parenchyma and liver disease largely due to unsecreted polymerized accumulations of misfolded mutant A1AT within the endoplasmic reticulum of hepatocytes. Since 1987, the only FDA licensed specific therapy for the emphysema component has been infusions of A1AT purified from pooled human plasma at the 2020 cost of up to US $200,000/year with the risk of intermittent shortages. In the past three decades various, potentially less expensive, recombinant forms of human A1AT have reached early stages of development, one of which is just reaching the stage of human clinical trials. The focus of this review is to update strategies for the treatment of the pulmonary component of A1ATD with some focus on perspectives for therapeutic production and regulatory approval of a recombinant product from plants. We review other competitive technologies for treating the lung disease manifestations of A1ATD, highlight strategies for the generation of data potentially helpful for securing FDA Investigational New Drug (IND) approval and present challenges in the selection of clinical trial strategies required for FDA licensing of a New Drug Approval (NDA) for this disease.

Alpha-1 Antitrypsin Deficiency and Pregnancy

Alpha-1 Antitrypsin Deficiency (A1AD) is a hereditary condition characterized by low levels of circulating alpha-antitrypsin (AAT) in plasma. It is the best understood genetic risk factor for the development of chronic obstructive pulmonary disease (COPD). The diagnosis of A1AD is under-recognized. While there is a significant heterogeneity in disease presentation in relation to the severity of symptoms and prognosis, it is not uncommon for young individuals, including pregnant women to already have moderate to advanced lung disease at the time of diagnosis. Reductions in AAT levels may have unique implications for a gravid patient beyond that of lung disease. Care of the pregnant A1AD patient with chronic lung disease follows the principles of care for the management of airways disease in general with control of symptoms and reduction in exacerbation risk the main tenets of treatment. The effect of A1AD and augmentation in pregnancy has not been studied and thus care is reliant on expert opinion and clinical experience. Providers caring for pregnant patients with A1AD should consider referral to health care systems and providers with specific expertise in A1AD. Ultimately the decision is left to the individual patient and their physician to weigh the risk benefit of cessation or continuation of therapies. In this review, we present the perinatal course of a woman with A1AD and review the available literature pertaining to AAT and pregnancy and discuss the clinical implications.

Alpha-1 Antitrypsin Deficiency and Accelerated Aging: A New Model for an Old Disease?

Alpha-1 antitrypsin (AAT) protects the lung by inhibiting neutrophil proteinases, but AAT has many other non-proteolytic functions that are anti-inflammatory, antiviral and homeostatic. Approximately 1 in 1600 to 1 in 5000 people have the homozygous Z mutation, which causes AAT misfolding, accumulation in (predominantly) liver cells and low circulating levels of AAT, leading to AAT deficiency (AATD). AATD is classically a disease of neutrophilic inflammation, with an aggressive and damaging innate immune response contributing to emphysema and other pathologies. AATD is one of the most common genetic disorders but considerably under-recognised. Most patients are diagnosed later in life, by which time they may have accumulated significant lung, liver and multisystem damage. Disease presentation is heterogeneous and not fully explained by deficiency levels alone or exposure to cigarette smoking. This suggests other factors influence AATD-associated pathological processes. Aging itself is associated with organ dysfunction, including emphysema and airflow obstruction, inflammation, altered immune cell responses (termed immunosenescence) and a loss of proteostasis. Many of these processes are present in AATD but at an earlier age and more advanced stage compared with chronological aging alone. Augmentation therapy does not completely abrogate the manifold disease processes present in AATD. New approaches are needed. There is emerging evidence that both age- and AATD-related disease processes are amenable to correction by targeting proteostasis, autophagy, immunosenescence and epigenetic factors. This review explores the impact of the aging process on AATD presentation and discusses novel therapeutic strategies to mitigate low levels of AAT or misfolded AAT in an aging host.

Calcium signalling in mammalian cell lines expressing wild type and mutant human α1-Antitrypsin

A possible role for calcium signalling in the autosomal dominant form of dementia, familial encephalopathy with neuroserpin inclusion bodies (FENIB), has been proposed, which may point towards a mechanism by which cells could sense and respond to the accumulation of mutant serpin polymers in the endoplasmic reticulum (ER). We therefore explored possible defects in Ca²⁺-signalling, which may contribute to the pathology associated with another serpinopathy, α₁-antitrypsin (AAT) deficiency. Using CHO K1 cell lines stably expressing a wild type human AAT (MAAT) and a disease-causing polymer-forming variant (ZAAT) and the truncated variant (NHK AAT), we measured basal intracellular free Ca²⁺, its responses to thapsigargin (TG), an ER Ca²⁺-ATPase blocker, and store-operated Ca²⁺-entry (SOCE). Our fura2 based Ca²⁺ measurements detected no differences between these 3 parameters in cell lines expressing MAAT and cell lines expressing ZAAT and NHK AAT mutants. Thus, in our cell-based models of α1-antitrypsin (AAT) deficiency, unlike the case for FENIB, we were unable to detect defects in calcium signalling.

Experimental and investigational drugs for the treatment of alpha-1 antitrypsin deficiency

Introduction: Alpha-1 antitrypsin deficiency (AATD) is most often associated with chronic lung disease, early onset emphysema, and liver disease. The standard of care in lung disease due to AATD is alpha-1 antitrypsin augmentation but there are several new and emerging treatment options under investigation for both lung and liver manifestations. Areas covered: We review therapeutic approaches to lung and liver disease in alpha-1 antitrypsin deficiency (AATD) and the agents in clinical development according to their mode of action. The focus is on products in clinical trials, but data from pre-clinical studies are described where relevant, particularly where progression to trials appears likely. Expert opinion: Clinical trials directed at lung and liver disease separately are now taking place. Multimodality treatment may be the future, but this could be limited by treatment costs. The next 5-10 years may reveal new guidance on when to use therapeutics for slowing disease progression with personalized treatment regimes coming to the forefront.

Alpha-1 Antitrypsin-Expressing Mesenchymal Stromal Cells Confer a Long-Term Survival Benefit in a Mouse Model of Lethal GvHD

Acute graft-versus-host disease is a frequent complication associated with allogeneic hematopoietic stem cell transplantation. Patients that become refractory to initial steroid treatment have a poor prognosis. apceth-201 consists of human allogeneic mesenchymal stromal cells, engineered by lentiviral transduction to express the protease inhibitor alpha-1 antitrypsin, to augment the anti-inflammatory potential of the mesenchymal stromal cells. We show that apceth-201 mesenchymal stromal cells efficiently suppress T cell proliferation and polarize macrophages to an anti-inflammatory M2 type, in vitro. To assess the in vivo efficacy of apceth-201, it was tested in two different mouse models of acute graft-versus-host disease. Control animals in a humanized model succumbed quickly to disease, whereas median survival was doubled in apceth-201-treated animals. The product was also tested in a graft-versus-host disease model system that closely mimics haploidentical hematopoietic stem cell transplantation, an approach that is now being evaluated for use in the clinic. Control animals succumbed quickly to disease, whereas treatment with apceth-201 resulted in long-term survival of 57% of the animals. Within 25 days after the second injection, clinical scores returned to baseline in responding animals, indicating complete resolution of graft-versus-host disease. These promising data have led to planning of a phase I study using apceth-201.

Comparing Patients with ZZ Versus SZ Alpha-1 Antitrypsin Deficiency: Findings from AlphaNet's Disease Management Program

Background: The aim of this study was to examine differences in demographic, health, and behavioral characteristics in individuals with ZZ and SZ genotypes of alpha-1 antitrypsin deficiency (AATD) within AlphaNet's Disease Management and Prevention Program (ADMAPP). Methods: Self-reported data from 3535 patients with AATD, including 3031 (85.7%) patients with ZZ, ZNull, and NullNull genotypes (referred to here as ZZ), and 504 (14.3%) with the SZ genotype were analyzed using t-tests, ANOVAs, and Chi-squared tests. Results: The average age of the cohort was 56.3±10.6 years. The majority of respondents were male (51.2%), white (98.2%) and married (65.2%). SZs reported having more frequent exacerbations (p<0.001) and hospitalizations (p=0.012) than ZZs. A higher proportion of SZs than ZZs had been diagnosed with high blood pressure, diabetes, congestive heart failure, and other comorbid conditions. SZs were more likely than ZZs to report "poor" health (p=0.005). Over a third (38.4%) of SZs do not exercise compared to 27.1% of ZZs (p<0.001). A greater proportion of SZs compared to ZZs view themselves as being overweight (p<0.001) or "out of shape" (p=0.001). A higher proportion of SZs than ZZs reported any history of smoking and current smoking (p<0.001). Conclusions: In patients with AATD and lung disease participating in a disease management program, a higher proportion of SZs than ZZs report exacerbations, comorbidities, and overall poor health, as well as unhealthy behaviors such as lack of exercise and current smoking. Future work should consider the extent to which genotype-specific health promotion interventions would be useful.

Alpha-1 Antitrypsin Therapy for Autoimmune Disorders

Autoimmune diseases are conditions caused by an over reactive immune system that attacks self-tissues and organs. Although the pathogenesis of autoimmune disease is complex and multi-factorial, inflammation is commonly involved. Therefore, anti-inflammatory therapies hold potential for the treatment of autoimmune diseases. However, long-term control of inflammation is challenging and most of the currently used drugs have side effects. Alpha-1 antitrypsin (AAT) is an anti-inflammatory protein with a well-known safety profile. The therapeutic potential of AAT has been tested in several autoimmune disease models. The first study using a recombinant adeno-associated viral (rAAV) vector showed that AAT gene transfer prevented the development of type 1 diabetes (T1D) in the non-obese diabetic (NOD) mouse model. Subsequent studies showed that treatment with AAT protein prevented and reversed type 1 diabetes. The beneficial effects of AAT treatment have also been observed in other autoimmune disease models such as rheumatoid arthritis and systemic lupus erythematosus. This paper reviews the therapeutic application of AAT and discusses possible mechanisms of action in various autoimmune diseases.

Alpha-1 Antitrypsin Substitution for Extrapulmonary Conditions in Alpha-1 Antitrypsin Deficient Patients

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder which most commonly manifests as pulmonary emphysema. Accordingly, alpha-1 antitrypsin (AAT) augmentation therapy aims to reduce the progression of emphysema, as achieved by life-long weekly slow-drip infusions of plasma-derived affinity-purified human AAT. However, not all AATD patients will receive this therapy, due to either lack of medical coverage or low patient compliance. To circumvent these limitations, attempts are being made to develop lung-directed therapies, including inhaled AAT and locally-delivered AAT gene therapy. Lung transplantation is also an ultimate therapy option. Although less common, AATD patients also present with disease manifestations that extend beyond the lung, including vasculitis, diabetes and panniculitis, and appear to experience longer and more frequent hospitalization times and more frequent pneumonia bouts. In the past decade, new mechanism-based clinical indications for AAT therapy have surfaced, depicting a safe, anti-inflammatory, immunomodulatory and tissue-protective agent. Introduced to non-AATD individuals, AAT appears to provide relief from steroid-refractory graft-versus-host disease, from bacterial infections in cystic fibrosis and from autoimmune diabetes; preclinical studies show benefit also in multiple sclerosis, ulcerative colitis, rheumatoid arthritis, acute myocardial infarction and stroke, as well as ischemia-reperfusion injury and aberrant wound healing processes. While the current augmentation therapy is targeted towards treatment of emphysema, it is suggested that AATD patients may benefit from AAT augmentation therapy geared towards extrapulmonary pathologies as well. Thus, development of mechanism-based, context-specific AAT augmentation therapy protocols is encouraged. In the current review, we will discuss extrapulmonary manifestations of AATD and the potential of AAT augmentation therapy for these conditions.

Intrapleural Gene Therapy for Alpha-1 Antitrypsin Deficiency-Related Lung Disease

Alpha-1 antitrypsin deficiency (AATD) manifests primarily as early-onset emphysema caused by the destruction of the lung by neutrophil elastase due to low amounts of the serine protease inhibitor alpha-1 antitrypsin (AAT). The current therapy involves weekly intravenous infusions of AAT-derived from pooled human plasma that is efficacious, yet costly. Gene therapy applications designed to provide constant levels of the AAT protein are currently under development. The challenge is for gene therapy to provide sufficient amounts of AAT to normalize the inhibitor level and anti-neutrophil elastase capacity in the lung. One strategy involves administration of an adeno-associated virus (AAV) gene therapy vector to the pleural space providing both local and systemic production of AAT to reach consistent therapeutic levels. This review focuses on the strategy, advantages, challenges, and updates for intrapleural administration of gene therapy vectors for the treatment of AATD.

Alpha1 antitrypsin deficiency due to an homozygous PI* Null Q0Cairo mutation: Early onset of pulmonary manifestations and variability of clinical expression

Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene. This genetic disorder is mainly associated with development of pulmonary emphysema and/or chronic liver disease and cirrhosis. Here we report a very rare alpha-1 antitrypsin Null Q0cairo homozygous mutation characterized by a complete absence of alpha-1 antitrypsin in the plasma, in a non-consanguineous Moroccan family. This mutation has been previously described in heterozygosis in only three cases worldwide: an Italian/Egyptian family and two Italian families (Zorzetto et al., 2005). The main clinical features in two members of this Moroccan family were the severity and precocity of bronchiectasis, quickly spreading and seriously limiting respiratory function and physical activity by the second decade of age. Moreover, the index case presented with many episodes of pulmonary infections concomitant with severe neutropenia. The third member of the family presented with ankylosing spondyloarthritis and developed panniculitis later but had no respiratory symptoms. The presence of this alpha-1-antitrypsin Q0cairo homozygous mutation could explain the severity of clinical manifestations. Moreover, our observations highlight a great variability of clinical expression for the same mutation: early severe bronchiectasis, panniculitis, rheumatologic manifestations. This study further underlines the importance of genotyping by whole SERPINA1 gene sequencing in addition to serum alpha-1 antitrypsin determination, to enable detection of alpha-1 antitrypsin deficiency due to rare genotypes.

Fulminant hepatic failure in the setting of progressive ANCA-associated vasculitis associated with a rare alpha-1 antitrypsin phenotype, 'PiEE'

Abnormalities in alpha-1 antitrypsin (AAT) proteins are risk factors for human disease. While the most common is AAT deficiency, a genetic disorder associated with chronic obstructive pulmonary disease, additional disorders associated with AAT abnormalities are increasingly recognised. We describe a middle-aged woman who presented with fulminant hepatic and multiorgan failure. Evaluation revealed the patient to have a rare AAT phenotype PiEE. Her clinical presentation was consistent with antineutrophilic cytoplasmic antibody-associated vasculitis, and her history suggested features of panniculitis. This is the first description of this rare homozygous AAT phenotype and possible disease associations with the ’E' protein. Given that abnormal AAT are under-recognised, and that new mutations and phenotypes continue to be identified, we will need to expand on our knowledge base and report clinical manifestations associated with these abnormal phenotypes.

Description of a new rare alpha-1 antitrypsin mutation in Naples (Italy): PI*M S-Napoli

Alpha-1 antitrypsin deficiency is a rare and often underdiagnosed hereditary disorder, which mainly affects the Caucasian population. We report a case of a noncystic fibrosis bronchiectasis patient in the absence of emphysema associated with low serum alpha-1-antitrypsin (AAT) level, in the absence of the most common defective alleles associated with AAT deficiency (PI*S and PI*Z) but with a new mutation in heterozygosis. This mutation is characterized by the substitution in the coding region of exon 3, of a guanine (G) for a thymine (T), generating the replacement of a glutamine (Gln) by a histidine (His) in codon 212 (cod 212 GlnCAG > HisCAT), corresponds to a new S allelic variant. This mutation, never identified before, is called S-Napoli.

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.

Alpha-1 antitrypsin Pi*Z gene frequency and Pi*ZZ genotype numbers worldwide: an update

In alpha-1 antitrypsin deficiency (AATD), the Z allele is present in 98% of cases with severe disease, and knowledge of the frequency of this allele is essential from a public health perspective. However, there is a remarkable lack of epidemiological data on AATD worldwide, and many of the data currently used are outdated. Therefore, the objective of this study was to update the knowledge of the frequency of the Z allele to achieve accurate estimates of the prevalence and number of Pi*ZZ genotypes worldwide based on studies performed according to the following criteria: 1) samples representative of the general population, 2) AAT phenotyping characterized by adequate methods, and 3) measurements performed using a coefficient of variation calculated from the sample size and 95% confidence intervals. Studies fulfilling these criteria were used to develop maps with an inverse distance weighted (IDW)-interpolation method, providing numerical and graphical information of Pi*Z distribution worldwide. A total of 224 cohorts from 65 countries were included in the study. With the data provided by these cohorts, a total of 253,404 Pi*ZZ were estimated worldwide: 119,594 in Europe, 91,490 in America and Caribbean, 3,824 in Africa, 32,154 in Asia, 4,126 in Australia, and 2,216 in New Zealand. In addition, the IDW-interpolation maps predicted Pi*Z frequencies throughout the world even in some areas that lack real data. In conclusion, the inclusion of new well-designed studies and the exclusion of the low-quality ones have significantly improved the reliability of results, which may be useful to plan strategies for future research and diagnosis and to rationalize the therapeutic resources available.

Neutrophils in ulcerative colitis: a review of selected biomarkers and their potential therapeutic implications

OBJECTIVES

This review article describes the role of neutrophils in mucosal injury and the resulting crypt abscesses characteristic of ulcerative colitis. We also review selected biomarkers for monitoring neutrophil presence and activity in the mucosa as well as their potential as therapeutic targets.

MATERIAL

We have collated and selectively reviewed data on the most prominent well-established and emerging neutrophil-related biomarkers and potential therapeutic targets (calprotectin, lactoferrin, CXCR1, CXCR2, MMP-9, NGAL, elafin, HNE, pANCAs, MPO, CD16, CD177, CD64, HNPs, SLPI and PTX3) in ulcerative colitis.

RESULTS

Systemic and intestinal neutrophil activity increases substantially in active ulcerative colitis, driving tissue damage and extra-intestinal manifestations. Calprotectin is a robust neutrophil and disease biomarker, and a few neutrophil-related targets are being clinically explored as therapeutic targets.

CONCLUSION

We propose that targeting neutrophils and their inflammatory mediators per se is an opportunity that should be explored to identify new effective medical therapies. The overall clinical goal for neutrophil-targeted therapy will be to modulate, but not completely silence, neutrophil activity, thereby abolishing the destructive inflammation with associated acute and chronic tissue damage without compromising host-defense.

Gene Therapy for Alpha-1 Antitrypsin Deficiency Lung Disease

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.

Antitrypsin Deficiency Assessment and Programme for Treatment (ADAPT): The United Kingdom Registry

The study of rare diseases is compromised by its rarity. The establishment of national and international registries can overcome many of the problems and be used for many monogenetic conditions with relatively consistent outcomes and thus lead to a consistency of clinical management by centres of excellence. However, in Alpha-1 antitrypsin deficiency (AATD), the outcome is highly variable in terms of the organ(s) most affected and the diversity of disease penetration and progression. This creates the added difficulty of understanding the disease sufficiently to monitor and advise the patients to the standard required and importantly design and deliver clinical trials that address the many facets of the disease. The development of research registries and centres of excellence provides the necessary expertise and data to further the understanding and management of diseases like AATD though with significant cost implications. The ADAPT programme was established in 1996 with extensive core funding to enable patients to be seen from all regions of the United Kingdom as an addition to the National Health Service without appointment time constraints and with the purpose of collecting extensive state of the art demographics. The model has proven to be highly productive providing new insights especially into the lung disease, generating and delivering on clinical trials and importantly establishing active patient groups and participation.

The multiple facets of alpha-1-antitrypsin

Alpha-1-antitrypsin (AAT) is recognised as a potent inhibitor of serine proteinases. Genetic deficiency is associated with several neutrophilic diseases including severe emphysema. This is believed to reflect the loss of inhibition of neutrophilic serine proteinases that then result in local tissue damage (the proteinase/antiprotease hypothesis). In recent years the role of AAT in the control of inflammatory and immunological processes has become identified. Although in some instances this may reflect its ability to control pro-inflammatory effects of serine proteinases it has also become recognised that it has non proteolytic mediated functions. This poly functional role is starting to become recognised offering a possibility of its use as a therapeutic agent in many clinical disease areas. The current review explores both the traditional and non-traditional function of AAT through published literature.

Alpha-1 antitrypsin and granulocyte colony-stimulating factor as serum biomarkers of disease severity in ulcerative colitis

BACKGROUND

Initial assessment of patients with ulcerative colitis (UC) is challenging and relies on apparent clinical symptoms and measurements of surrogate markers (e.g., C-reactive protein [CRP] or similar acute phase proteins). As CRP only reliably identifies patients with severe disease, novel biomarkers are currently needed for identification of patients with mild or moderate disease activity. Using a commercially available platform, we aimed at identifying serum biomarkers that are able to grade the disease severity.

METHODS

Serum samples from 65 patients with UC with varying disease activity (Mayo score) and from 40 healthy controls were analyzed by multiplex enzyme-linked immunosorbent assay for 78 potential disease biomarkers. Using the statistical software SIMCA-P+ and GraphPad Prism, multivariate statistical analyses were conducted to identify a limited number of biomarkers to assess disease severity.

RESULTS

Alpha-1 antitrypsin (AAT) differentiated between mild and moderate UC (area under the curve [AUC] = 0.79) with a sensitivity of 0.90 and a specificity of 0.70, thereby exceeding the predictive ability of CRP (AUC = 0.52). Combining alpha-1 antitrypsin and granulocyte colony-stimulating factor produced a predictive model with an AUC of 0.72 when differentiating mild and moderate UC, and an AUC of 0.96 when differentiating moderate and severe UC, the latter being as reliable as CRP.

CONCLUSIONS

Alpha-1 antitrypsin is identified as a potential serum biomarker of mild-to-moderate disease activity in UC. With the ability to differentiate between mild, moderate, and severe stages of UC using a simple serum biomarker that is already commercially available, clinicians can initiate individualized treatment regimens at an earlier stage before endoscopic examinations are available.

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.

Severe postoperative wound healing disturbance in a patient with alpha-1-antitrypsin deficiency: the impact of augmentation therapy

Wound healing disturbance is a common complication following surgery, but the underlying cause sometimes remains elusive. A 50-year-old Caucasian male developed an initially misunderstood severe wound healing disturbance following colon and abdominal wall surgery. An untreated alpha-1-antitrypsin (AAT) deficiency in the patient's medical history, known since 20 years and clinically apparent as a mild to moderate chronic obstructive pulmonary disease, was eventually found to be at its origin. Further clinical work-up showed AAT serum levels below 30% of the lower reference value; phenotype testing showed a ZZ phenotype and a biopsy taken from the wound area showed the characteristic, disease-related histological pattern of necrotising panniculitits. Augmentation therapy with plasma AAT was initiated and within a few weeks, rapid and adequate would healing was observed. AAT deficiency is an uncommon but clinically significant, possible cause of wound healing disturbances. An augmentation therapy ought to be considered in affected patients during the perioperative period.

Acute-phase protein α1-anti-trypsin: diverting injurious innate and adaptive immune responses from non-authentic threats

One would assume that the anti-inflammatory activity of α1-anti-trypsin (AAT) is the result of inhibiting neutrophil enzymes. However, AAT exhibits tolerogenic activities that are difficult to explain by serine-protease inhibition or by reduced inflammatory parameters. Targets outside the serine-protease family have been identified, supporting the notion that elastase inhibition, the only functional factory release criteria for clinical-grade AAT, is over-emphasized. Non-obvious developments in the understanding of AAT biology disqualify it from being a straightforward anti-inflammatory agent: AAT does not block dendritic cell activities, nor does it promote viral and tumour susceptibilities, stunt B lymphocyte responses or render treated patients susceptible to infections; accordingly, outcomes of elevated AAT do not overlap those attained by immunosuppression. Aside from the acute-phase response, AAT rises during the third trimester of pregnancy and also in advanced age. At the molecular level, AAT docks onto cholesterol-rich lipid-rafts and circulating lipid particles, directly binds interleukin (IL)-8, ADAM metallopeptidase domain 17 (ADAM17) and danger-associated molecular pattern (DAMP) molecules, and its activity is lost to smoke, high glucose levels and bacterial proteases, introducing a novel entity - 'relative AAT deficiency'. Unlike immunosuppression, AAT appears to help the immune system to distinguish between desired responses against authentic threats, and unwanted responses fuelled by a positive feedback loop perpetuated by, and at the expense of, inflamed injured innocent bystander cells. With a remarkable clinical safety record, AAT treatment is currently tested in clinical trials for its potential benefit in a variety of categorically distinct pathologies that share at least one common driving force: cell injury.

Patterns of airway involvement in inflammatory bowel diseases

Extraintestinal manifestations occur commonly in inflammatory bowel diseases (IBD). Pulmonary manifestations (PM) of IBD may be divided in airway disorders, interstitial lung disorders, serositis, pulmonary vasculitis, necrobiotic nodules, drug-induced lung disease, thromboembolic lung disease and enteropulmonary fistulas. Pulmonary involvement may often be asymptomatic and detected solely on the basis of abnormal screening tests. The common embryonic origin of the intestine and the lungs from the primitive foregut, the co-existence of mucosa associated lymphoid tissue in both organs, autoimmunity, smoking and bacterial translocation from the colon to the lungs may all be involved in the pathogenesis of PM in IBD. PM are mainly detected by pulmonary function tests and high-resolution computed tomography. This review will focus on the involvement of the airways in the context of IBD, especially stenoses of the large airways, tracheobronchitis, bronchiectasis, bronchitis, mucoid impaction, bronchial granulomas, bronchiolitis, bronchiolitis obliterans syndrome and the co-existence of IBD with asthma, chronic obstructive pulmonary disease, sarcoidosis and a1-antitrypsin deficiency.