Alpha-1 antitrypsin deficiency-associated panniculitis

Glycoconjugates: Advances in modern medicines and human health

Glycans and their glycoconjugates are complex biomolecules that are crucial for various biological processes. Glycoconjugates are found in all domains of life. They are covalently linked to key biomolecules such as proteins and lipids to play a pivotal role in cell signaling, adhesion, and recognition. The diversity of glycan structures and the associated complexity of glycoconjugates is the reason for their role in intricate biosynthetic pathways. Glycoconjugates play an important role in various diseases where they are actively involved in the immune response as well as in the pathogenicity of infectious diseases. In addition, various autoimmune diseases have been linked to glycosylation defects of different biomolecules, making them an important molecule in the field of medicine. The glycoconjugates have been explored for the development of therapeutics and vaccines, representing a breakthrough in medical science. They also hold significance in research studies to understand the mechanisms behind various biological processes. Finally, glycoconjugates have found an emerging role in various industrial and environmental applications which have been discussed here.

Neutrophilic Panniculitides

Neutrophilic panniculitides are a heterogeneous group of inflammatory disorders encompassing many different entities. This review article focuses on the epidemiology, pathogenesis, clinicopathological features, diagnosis, and treatment of selected diseases. Patients often seek care due to systemic involvement, but the variable presentation of panniculitides can present a diagnostic challenge. Most therapeutic modalities for neutrophilic disorders are anecdotal at best with a notable lack of standardization of the responses to medications. There is an urgent need for a larger multi-institutional collaboration to address the unmet needs of these challenging, yet rare conditions.

Alpha1-antitrypsin deficiency in Greece: Focus on rare variants

PURPOSE

A1Antitrypsin deficiency (AATD) pathogenic mutations are expanding beyond the PI*Z and PI*S to a multitude of rare variants.

AIM

to investigate genotype and clinical profile of Greeks with AATD.

METHODS

Symptomatic adult-patients with early-emphysema defined by fixed airway obstruction and computerized-tomography scan and lower than normal serum AAT levels were enrolled from reference centers all over Greece. Samples were analyzed in the AAT Laboratory, University of Marburg-Germany.

RESULTS

Included are 45 adults, 38 homozygous or compound heterozygous for pathogenic variants and 7 heterozygous. Homozygous were 57.9% male, 65.8% ever-smokers, median (IQR) age 49.0(42.5-58.5) years, AAT-levels 0.20(0.08-0.26) g/L, FEV1(%predicted) 41.5(28.8-64.5). PI*Z, PI*Q0, and rare deficient allele's frequency was 51.3%, 32.9%,15.8%, respectively. PI*ZZ genotype was 36.8%, PI*Q0Q0 21.1%, PI*MdeficientMdeficient 7.9%, PI*ZQ0 18.4%, PI*Q0Mdeficient 5.3% and PI*Zrare-deficient 10.5%. Genotyping by Luminex detected: p.(Pro393Leu) associated with MHeerlen (M1Ala/M1Val); p.(Leu65Pro) with MProcida; p.(Lys241Ter) with Q0Bellingham; p.(Leu377Phefs*24) with Q0Mattawa (M1Val) and Q0Ourem (M3); p.(Phe76del) with MMalton (M2), MPalermo (M1Val), MNichinan (V) and Q0LaPalma (S); p.(Asp280Val) with PLowell (M1Val); PDuarte (M4), YBarcelona (p.Pro39His). Gene-sequencing (46.7%) detected Q0GraniteFalls, Q0Saint-Etienne, Q0Amersfoort(M1Ala), MWürzburg, NHartfordcity and one novel-variant (c.1A>G) named Q0Attikon.Heterozygous included PI*MQ0Amersfoort(M1Ala), PI*MMProcida, PI*Mp.(Asp280Val), PI*MOFeyzin. AAT-levels were significantly different between genotypes (p = 0.002).

CONCLUSION

Genotyping AATD in Greece, a multiplicity of rare variants and a diversity of rare combinations, including unique ones were observed in two thirds of patients, expanding knowledge regarding European geographical trend in rare variants. Gene sequencing was necessary for genetic diagnosis. In the future the detection of rare genotypes may add to personalize preventive and therapeutic measures.

Characterization of Novel Alpha-1-Antitrypsin Coding Variants in a Mammalian Cellular Model

Advances in genetic screening technologies have considerably accelerated the discovery of rare alpha-1-antitrypsin (AAT) variants. Expression in cellular models is an effective approach to evaluate the pathogenic potential of these new AAT variants, whose clinical significance would otherwise remain uncertain. Here we provide a detailed description of established methods for in vitro characterization of AAT coding variants expressed in HEK293T/17 cells. The protocols include determination of secretion efficiency, the tendency to form polymeric chains and  the anti-elastase inhibitory activity.

Dipeptidyl peptidase 1 inhibition as a potential therapeutic approach in neutrophil-mediated inflammatory disease

Neutrophils have a critical role in the innate immune response to infection and the control of inflammation. A key component of this process is the release of neutrophil serine proteases (NSPs), primarily neutrophil elastase, proteinase 3, cathepsin G, and NSP4, which have essential functions in immune modulation and tissue repair following injury. Normally, NSP activity is controlled and modulated by endogenous antiproteases. However, disruption of this homeostatic relationship can cause diseases in which neutrophilic inflammation is central to the pathology, such as chronic obstructive pulmonary disease (COPD), alpha-1 antitrypsin deficiency, bronchiectasis, and cystic fibrosis, as well as many non-pulmonary pathologies. Although the pathobiology of these diseases varies, evidence indicates that excessive NSP activity is common and a principal mediator of tissue damage and clinical decline. NSPs are synthesized as inactive zymogens and activated primarily by the ubiquitous enzyme dipeptidyl peptidase 1, also known as cathepsin C. Preclinical data confirm that inactivation of this protease reduces activation of NSPs. Thus, pharmacological inhibition of dipeptidyl peptidase 1 potentially reduces the contribution of aberrant NSP activity to the severity and/or progression of multiple inflammatory diseases. Initial clinical data support this view. Ongoing research continues to explore the role of NSP activation by dipeptidyl peptidase 1 in different disease states and the potential clinical benefits of dipeptidyl peptidase 1 inhibition.

Impact of the COVID-19 pandemic on well-being and quality of life of patients with alpha-1-antitrypsin deficiency

BACKGROUND

Alpha-1-antitrypsin deficiency (AATD) is a genetic disorder characterized by mutations in the SERPINA1 gene, primarily affecting the lungs and liver. The COVID-19 pandemic has raised questions about the susceptibility of individuals with AATD to COVID-19 and whether patients with rare lung disease might experience increased stress-related symptoms and mental health challenges. This study aims to investigate the impact of the COVID-19 pandemic on the quality of life of individuals living with AATD.

METHODS

The study enrolled participants from the German registry for individuals with AATD. Questionnaires were sent to the 1250 participants, and a total of 358 patients were included in the analysis. The primary objective was to examine the influence of sociodemographic and disease-related factors on the occurrence of stress-related symptoms. This was accomplished through correlation and regression analyses. We also investigated the role of baseline quality of life (QoL), as measured by the St. George's Respiratory Questionnaire (SGRQ), as a mediator of this relationship.

RESULTS

Stress-related symptoms were predicted by young age, female gender, psychological disorders, and a history of exacerbations of lung disease, as determined by multiple regression analysis. QoL as measured by the SGRQ mediated the relationship between poor lung function, stress, and a decline in overall well-being.

CONCLUSION

The presented data demonstrate that the COVID-19 pandemic significantly affects the psychological well-being of patients with rare diseases, leading to increased levels of anxiety and stress. Disease-related factors can exacerbate stress manifestations, especially when compounded by sociodemographic and contextual factors. Thus, our study emphasizes the crucial role of taking these factors into account when managing individuals with AATD in pandemic situations.

Comprehensive Clinical Diagnostic Pipelines Reveal New Variants in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is an underdiagnosed disorder associated with mutations in the SERPINA1 gene encoding alpha-1 antitrypsin (AAT). Severe AATD can manifest as pulmonary emphysema and progressive liver disease. Besides the most common pathogenic variants S (E264V) and Z (E342K), many rarer genetic variants of AAT have been found in patients and in the general population. Here we report a panel of new SERPINA1 variants, including 4 null and 16 missense alleles, identified among a cohort of individuals with suspected AATD whose phenotypic follow-up showed inconclusive or atypical results. Because the pathogenic significance of the missense variants was unclear purely on the basis of clinical data, the integration of computational, biochemical, and cellular studies was used to define the associated risk of disease. Established pathogenicity predictors and structural analysis identified a panel of candidate damaging mutations that were characterized by expression in mammalian cell models. Polymer formation, intracellular accumulation, and secretory efficiency were evaluated experimentally. Our results identified two AAT mutants with a Z-like polymerogenic severe deficiency profile (Smilano and Mcampolongo) and three milder variants (Xsarezzo, Pdublin, and Ctiberias). Overall, the experimentally determined behavior of the variants was in agreement with the pathogenicity scores of the REVEL (an ensemble method for predicting the pathogenicity of rare missense variants) predictor, supporting the utility of this bioinformatic tool in the initial assessment of newly identified amino acid substitutions of AAT. Our study, in addition to describing 20 new SERPINA1 variants, provides a model for a multidisciplinary approach to classification of rare AAT variants and their clinical impact on individuals with rare AATD genotypes.

Alpha-1 antitrypsin deficiency: current therapy and emerging targets

INTRODUCTION

Alpha1 antitrypsin deficiency (AATD), a common hereditary disorder affecting mainly lungs, liver and skin has been the focus of some of the most exciting therapeutic approaches in medicine in the past 5 years. In this review, we discuss the therapies presently available for the different manifestations of AATD and new therapies in the pipeline.

AREAS COVERED

We review therapeutic options for the individual lung, liver and skin manifestations of AATD along with approaches which aim to treat all three. Along with this renewed interest in treating AATD come challenges. How is AAT best delivered to the lung? What is the desired level of AAT in the circulation and lungs which therapeutics should aim to provide? Will treating the liver disease increase the potential for lung disease? Are there treatments to target the underlying genetic defect with the potential to prevent all aspects of AATDrelated disease?

EXPERT OPINION

With a relatively small population able to participate in clinical studies, increased awareness and diagnosis of AATD is urgently needed. Better, more sensitive clinical parameters will assist in the generation of acceptable and robust evidence of therapeutic effect for current and emerging treatments.

COVID-19 Pathology Sheds Further Light on Balance between Neutrophil Proteases and Their Inhibitors

Excessive neutrophil influx and activation in lungs during infections, such as manifest during the ongoing SARS CoV-2 pandemic, have brought neutrophil extracellular traps (NETs) and the concomitant release of granule contents that damage surrounding tissues into sharp focus. Neutrophil proteases, which are known to participate in NET release, also enable the binding of the viral spike protein to cellular receptors and assist in the spread of infection. Blood and tissue fluids normally also contain liver-derived protease inhibitors that balance the activity of proteases. Interestingly, neutrophils themselves also express the protease inhibitor alpha-1-antitrypsin (AAT), the product of the SERPINA-1 gene, and store it in neutrophil cytoplasmic granules. The absence of AAT or mutations in the SERPINA-1 gene promotes lung remodeling and fibrosis in diseases such as chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome (ARDS) and increases the risk of allergic responses. Recent observations point to the fact that reduced activity of AAT presents a major susceptibility factor for severe COVID-19. Here, we focus attention on the mechanism of neutrophil elastase (NE) in NET release and its inhibition by AAT as an additional factor that may determine the severity of COVID-19.

Alpha-1 Antitrypsin Therapy Modifies Neutrophil Adhesion in Patients with Obstructive Lung Disease

Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by neutrophil-dominated inflammation resulting in emphysema. The cholesterol-rich neutrophil outer plasma membrane plays a central role in adhesion and subsequent transmigration to underlying tissues. This study aimed to investigate mechanisms of increased neutrophil adhesion in AATD, and whether AAT augmentation therapy abrogates this effect. Plasma and blood neutrophils were donated by healthy controls (n=20), AATD (n=30) and AATD patients post AAT augmentation therapy (n=6). Neutrophil membrane protein expression was investigated using liquid chromatography-tandem mass spectrometry. The effect of once weekly intravenous AAT augmentation therapy was assessed by ELISAs, and calcium fluorometric, μ-calpain and cell adhesion assays. Decreased neutrophil plasma membrane cholesterol content (P=0.03), yet increased abundance of integrin alpha-M (fold change 1.91), integrin alpha-L (fold change 3.76) and cytoskeletal adaptor proteins including talin-1 (fold change 4.04), were detected on AATD neutrophil plasma membrane fractions. The described inflammatory induced structural changes were a result of >2 fold increased cytosolic calcium levels (P=0.02), leading to significant calcium dependent μ-calpain activity (3.5 fold change, P=0.005), resulting in proteolysis of the membrane cholesterol trafficking protein caveolin-1. Treatment of AAT-deficient individuals with AAT augmentation therapy resulted in increased caveolin-1 and membrane cholesterol content (111.8 ± 15.5 vs 64.18 ± 7.8 µg/ 2x10⁷ cells pre- and post-treatment respectively, P=0.02), with concurrent decreased neutrophil integrin expression and adhesion. Results demonstrate an auxiliary benefit of AAT augmentation therapy, evident by a decrease in circulating inflammation and controlled neutrophil adhesion.

C3d Elicits Neutrophil Degranulation and Decreases Endothelial Cell Migration, with Implications for Patients with Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by increased risk for emphysema, chronic obstructive pulmonary disease (COPD), vasculitis, and wound-healing impairment. Neutrophils play a central role in the pathogenesis of AATD. Dysregulated complement activation in AATD results in increased plasma levels of C3d. The current study investigated the impact of C3d on circulating neutrophils. Blood was collected from AATD (n = 88) or non-AATD COPD patients (n = 10) and healthy controls (HC) (n = 40). Neutrophils were challenged with C3d, and degranulation was assessed by Western blotting, ELISA, or fluorescence resonance energy transfer (FRET) substrate assays. Ex vivo, C3d levels were increased in plasma (p < 0.0001) and on neutrophil plasma membranes (p = 0.038) in AATD compared to HC. C3d binding to CR3 receptors triggered primary (p = 0.01), secondary (p = 0.004), and tertiary (p = 0.018) granule release and increased CXCL8 secretion (p = 0.02). Ex vivo plasma levels of bactericidal-permeability-increasing-protein (p = 0.02), myeloperoxidase (p < 0.0001), and lactoferrin (p < 0.0001) were significantly increased in AATD patients. In endothelial cell scratch wound assays, C3d significantly decreased cell migration (p < 0.0001), an effect potentiated by neutrophil degranulated proteins (p < 0.0001). In summary, AATD patients had increased C3d in plasma and on neutrophil membranes and, together with neutrophil-released granule enzymes, reduced endothelial cell migration and wound healing, with potential implications for AATD-related vasculitis.

In vitro and in vivo modulation of NADPH oxidase activity and reactive oxygen species production in human neutrophils by α1-antitrypsin

Oxidative stress from innate immune cells is a driving mechanism that underlies COPD pathogenesis. Individuals with α-1 antitrypsin (AAT) deficiency (AATD) have a dramatically increased risk of developing COPD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil NADPH oxidase activation, due to the specific lack of plasma AAT.

Experiments were performed using circulating neutrophils isolated from healthy controls and individuals with AATD. Superoxide anion (O₂⁻) production was determined from the rate of reduction of cytochrome c. Quantification of membrane NADPH oxidase subunits was performed by mass spectrometry and Western blot analysis. The clinical significance of our in vitro findings was assessed in patients with AATD and severe COPD receiving intravenous AAT replacement therapy.

In vitro, AAT significantly inhibited O₂⁻ production by stimulated neutrophils and suppressed receptor stimulation of cyclic adenosine monophosphate and extracellular signal-regulated kinase (ERK)1/2 phosphorylation. In addition, AAT reduced plasma membrane translocation of cytosolic phox components of the NADPH oxidase. Ex vivo, AATD neutrophils demonstrated increased plasma membrane-associated p67^phox and p47^phox and significantly increased O₂⁻ production. The described variance in phox protein membrane assembly was resolved post-AAT augmentation therapy in vivo, the effects of which significantly reduced AATD neutrophil O₂⁻ production to that of healthy control cells.

These results expand our knowledge on the mechanism of neutrophil-driven airways disease associated with AATD. Therapeutic AAT augmentation modified neutrophil NADPH oxidase assembly and reactive oxygen species production, with implications for clinical use in conditions in which oxidative stress plays a pathogenic role.

Circulating neutrophils in COPD due to α₁-antitrypsin deficiency illustrate increased NADPH oxidase assembly and reactive oxygen species production, a defect corrected by α₁-antitrypsin augmentation therapyhttps://bit.ly/38NNTzM

Investigating the Link between Alpha-1 Antitrypsin Deficiency and Abdominal Aortic Aneurysms

BACKGROUND

Alpha-1-Antitrypsin (AAT) is one of the major plasmatic protease inhibitors. In the last decade, an association between Alpha-1-Antitrypsin Deficiency (AATD) and Abdominal Aortic Aneurysms (AAA) has been hypothesized. Multiple factors may be involved in AAA's etiopathogenesis, and an underlying structural defect of the extracellular matrix (ECM) is always present. AATD could be a reasonable risk factor for AAA because it is related to protease/antiprotease imbalance and enhanced ECM degradation of the vessel wall.

METHODS

We performed genotyping of 138 patients hospitalized in the Vascular Surgery Division of the ASST-Spedali Civili di Brescia, Italy, for nontraumatic rupture of AAA. The second purpose was to observe the distribution of main nongenetic risk factors for AAA between patients with and without AATD.

RESULTS

Out of 138 patients, 22 were found with AATD: 16 MS, 1 SS, 3 MZ, and 2 with a new rare AAT variant. When compared to the general Italian population, our cohort's frequency of deficient S allele was significantly higher (7.8 vs. 2.2% respectively, P < 0.01), whereas the deficient Z allele was similar (1.1 vs. 1.3% respectively, P > 0.05). Although we found no differences in age, gender, hypertension, diabetes, and smoke habits between AAA patients with and without AATD, hyperlipidemia was significantly less frequent in patients with AATD (46.4 vs. 12.5% respectively, P < 0.05).

CONCLUSIONS

In our AAA patients' cohort, the S allele frequency was higher than in the general Italian population. Our results support the hypothesis that AATD might be a risk factor for AAA.

Alpha-1 antitrypsin deficiency: clarifying the role of the putative protective threshold

AATD is the only readily identifiable monogenic cause of COPD. To date the only condition-specific treatment for AATD-associated COPD is weekly administration of intravenous purified pooled human AAT (IV-AAT). Uncertainties regarding which AATD genotypes should benefit from IV-AAT persist. IV-AAT is costly and involves weekly administration of a plasma product. Much of the risk stratification has been centred around the long-accepted hypothesis of a "putative protective threshold" of 11 µM (0.57 g·L^-1) in serum. This hypothesis has become central to the paradigm of AATD care, though its derivation and accuracy for defining risk of disease remain unclear.We review the literature and examine the association between the 11 µM threshold and clinical outcomes to provide context and insight into the issues surrounding this topic.We found no data which demonstrates an increased risk of COPD dependent on the 11 µM threshold. Moreover, an abundance of recent clinical data examining this threshold refutes the hypothesis. Conversely, the use of 11 µM as a treatment target in appropriate ZZ individuals is supported by clinical evidence, although more refined dosing regimens are being explored.Continued use of the 11 µM threshold as a determinant of clinical risk is questionable, perpetuates inappropriate AAT-augmentation practices, may drive increased healthcare expenditure and should not be used as an indicator for commencing treatment.Genotype represents a more proven indicator of risk, with ZZ and rare ZZ-equivalent genotypes independently associated with COPD. New and better risk assessment models are needed to provide individuals diagnosed with AATD with reliable risk estimation and optimised treatment goals.

Therapeutic Potential of Alpha-1 Antitrypsin in Type 1 and Type 2 Diabetes Mellitus

Alpha-1 antitrypsin (AAT) has established anti-inflammatory and immunomodulatory effects in chronic obstructive pulmonary disease but there is increasing evidence of its role in other inflammatory and immune-mediated conditions, like diabetes mellitus (DM). AAT activity is altered in both developing and established type 1 diabetes mellitus (T1DM) as well in established type 2 DM (T2DM). Augmentation therapy with AAT appears to favorably impact T1DM development in mice models and to affect β-cell function and inflammation in humans with T1DM. The role of AAT in T2DM is less clear, but AAT activity appears to be reduced in T2DM. This article reviews these associations and emerging therapeutic strategies using AAT to treat DM.