The prevalence of diagnosed α1-antitrypsin deficiency and its comorbidities: results from a large population-based database

Genetic background of pulmonary (vascular) diseases - how much is written in the codes?

PURPOSE OF REVIEW

To provide a comprehensive overview of the underlying genetic defects of pulmonary (vascular) diseases and novel treatment avenues.

RECENT FINDINGS

Pulmonary arterial hypertension (PAH) is the prime example of a pulmonary vascular disease, which can be caused by genetic mutations in some patients. Germline mutations in the BMPR2 gene and further genes lead to vessel remodelling, increase of pulmonary vascular resistance and onset of heritable PAH. The PAH genes with the highest evidence and strategies for genetic testing and counselling have been assessed and evaluated in 2023 by international expert consortia. Moreover, first treatment options have just arisen targeting the molecular basis of PAH.

SUMMARY

Apart from PAH, this review touches on the underlying genetic causes of further lung diseases including alpha 1 antitrypsin deficiency, cystic fibrosis, familial pulmonary fibrosis and lymphangioleiomyomatosis. We point out the main disease genes, the underlying pathomechanisms and novel therapies trying not only to relieve symptoms but to treat the molecular causes of the diseases.

Local Alpha1-Antitrypsin Accelerates the Healing of Tympanic Membrane Perforation in Mice

BACKGROUND

Most tympanic membrane (TM) perforations heal spontaneously, but 10%-20% remain chronic and might lead to impaired hearing and recurrent middle ear infections. Alpha1-antitrypsin (AAT) is a circulating tissue-protective protein that is elevated under inflammatory conditions and is currently indicated for genetic AAT deficiency. Recently, AAT has been shown to promote tissue remodeling and inflammatory resolution.

OBJECTIVE

This study aimed to examine the effects of local clinical-grade AAT treatment on tissue repair in a mouse model of acute traumatic TM perforation.

METHODS

Wild-type mice underwent unilateral TM perforation and were either left untreated or treated locally with human AAT (9 × 10-3 mL at 20 mg/mL on days 0, 1, and 2; n = 15/group). The perforations were evaluated macroscopically on a serial basis. Mice were sacrificed on various days post-injury, and TMs were excised for gene analysis by RT-PCR.

RESULTS

There were no adverse reactions in hAAT-treated ears throughout the study period. Compared with untreated animals, TM closure occurred earlier in the treated group (days until full closure, median: 4 and 9, respectively). According to gene expression analysis, VEGF, TGFβ, and collagen-5A1 were induced earlier in AAT-treated mice (day 4-5 compared with day 9). Additionally, IL-10 expression levels were higher and IL-6 levels were lower in treated versus untreated mice.

CONCLUSION

A local tissue environment rich in AAT promotes early tissue repair in a perforated TM model both macroscopically and molecularly. Studies are underway to examine TM functionality and recombinant AAT formulations for micro-dosing in the format of a single local application.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:3802-3806, 2024.

Racial inequities and rare CFTR variants: Impact on cystic fibrosis diagnosis and treatment

Cystic fibrosis (CF) has been traditionally viewed as a disease that affects White individuals. However, CF occurs among all races, ethnicities, and geographic ancestries. The disorder results from mutations in the CF transmembrane conductance regulator (CFTR). Varying incidence of CF is reported among Black, Indigenous, and People of Color (BIPOC), who typically exhibit worse clinical outcomes. These populations are more likely to carry rare CFTR variants omitted from newborn screening panels, leading to disparities in care such as delayed diagnosis and treatment. In this study, we present a case-in-point describing an individual of Gambian descent identified with CF. Patient genotype includes a premature termination codon (PTC) (c.2353C>T) and previously undescribed single nucleotide deletion (c.1970delG), arguing against effectiveness of currently available CFTR modulator-based interventions. Strategies for overcoming these two variants will likely include combinations of PTC suppressors, nonsense mediated decay inhibitors, and/or alternative approaches (e.g. gene therapy). Investigations such as the present study establish a foundation from which therapeutic treatments may be developed. Importantly, c.2353C>T and c.1970delG were not detected in the patient by traditional CFTR screening panels, which include an implicit racial and ethnic diagnostic bias as these tests are comprised of mutations largely observed in people of European ancestry. We suggest that next-generation sequencing of CFTR should be utilized to confirm or exclude a CF diagnosis, in order to equitably serve BIPOC individuals. Additional epidemiologic data, basic science investigations, and translational work are imperative for improving understanding of disease prevalence and progression, CFTR variant frequency, genotype-phenotype correlation, pharmacologic responsiveness, and personalized medicine approaches for patients with African ancestry and other historically understudied geographic lineages.

Alpha-1-antitrypsin-deficiency is associated with lower cardiovascular risk: an approach based on federated learning

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an inflammatory multisystemic disease caused by environmental exposures and/or genetic factors. Inherited alpha-1-antitrypsin deficiency (AATD) is one of the best recognized genetic factors increasing the risk for an early onset COPD with emphysema. The aim of this study was to gain a better understanding of the associations between comorbidities and specific biomarkers in COPD patients with and without AATD to enable future investigations aimed, for example, at identifying risk factors or improving care.

METHODS

We focused on cardiovascular comorbidities, blood high sensitivity troponin (hs-troponin) and lipid profiles in COPD patients with and without AATD. We used clinical data from six German University Medical Centres of the MIRACUM (Medical Informatics Initiative in Research and Medicine) consortium. The codes for the international classification of diseases (ICD) were used for COPD as a main diagnosis and for comorbidities and blood laboratory data were obtained. Data analyses were based on the DataSHIELD framework.

RESULTS

Out of 112,852 visits complete information was available for 43,057 COPD patients. According to our findings, 746 patients with AATD (1.73%) showed significantly lower total blood cholesterol levels and less cardiovascular comorbidities than non-AATD COPD patients. Moreover, after adjusting for the confounder factors, such as age, gender, and nicotine abuse, we confirmed that hs-troponin is a suitable predictor of overall mortality in COPD patients. The comorbidities associated with AATD in the current study differ from other studies, which may reflect geographic and population-based differences as well as the heterogeneous characteristics of AATD.

CONCLUSION

The concept of MIRACUM is suitable for the analysis of a large healthcare database. This study provided evidence that COPD patients with AATD have a lower cardiovascular risk and revealed that hs-troponin is a predictor for hospital mortality in individuals with COPD.

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.

Cardiovascular Risk Associated with Alpha-1 Antitrypsin Deficiency (AATD) Genotypes: A Meta-Analysis with Meta-Regressions

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) can result in severe liver and respiratory disorders. The uninhibited elastase activity on the elastic tissue of arterial walls suggests that AATD may also impact vascular health. Thus, we performed a meta-analysis of the studies evaluating cardiovascular risk in individuals with AATD and non-AATD controls.

METHODS

A systematic literature search was conducted in the main scientific databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Differences between cases and controls were expressed as odds ratios (OR) with 95% confidence intervals (95%CI). The protocol was registered on PROSPERO under the identification number CRD42023429756.

RESULTS

The analysis of eight studies showed that, with a prevented fraction of disease of 15.0% and a corresponding OR of 0.779 (95%CI: 0.665-0.912; p = 0.002), a total of 24,428 individuals with AATD exhibited a significantly lower risk of ischemic heart disease compared to 534,654 non-AATD controls. Accordingly, given a prevented fraction of disease of 19.5%, a lower risk of acute myocardial infarction was documented when analyzing four studies on 21,741 cases and 513,733 controls (OR: 0.774; 95%CI: 0.599-0.999; p = 0.049). Sensitivity and subgroup analyses substantially confirmed results. Meta-regression models suggested that these findings were not influenced by AATD genotypes or prevalence of chronic obstructive pulmonary disease (COPD) among cases and controls, while higher differences in the prevalence of male sex (Z-score: 3.40; p < 0.001), hypertension (Z-score: 2.31; p = 0.021), and diabetes (Z-score: 4.25; p < 0.001) were associated with a lower effect size.

CONCLUSIONS

Individuals with AATD may exhibit a reduced risk of ischemic heart disease, even in the presence of mild deficiency of the serine protease inhibitor. Although caution is warranted due to the observational nature of the data, future pharmacological and rehabilitation strategies should also take this controversial relationship into account.

Alpha1-antitrypsin deficiency: An updated review

Alpha1-antitrypsin deficiency (AATD) is a rare autosomal recessive disease associated with the homozygous Z variant of the SERPINA1 gene. Clinical expression of AATD, reported 60 years ago associate a severe deficiency, pulmonary emphysema and/or liver fibrosis. Pulmonary emphysema is due to the severe alpha1-antitrypsin deficiency of the ZZ homozygous status and is favored by smoking. Liver fibrosis is due to the ZZ homozygous status and is favored by obesity and excessive chronic alcohol intake, with a risk of liver cancer. Diagnosis is based on serum level and either isoelectric focusing determination of the biochemical phenotype or PCR detection of some variants. SERPINA1 gene sequencing is necessary in case of discrepancies between the results of these tests. No treatment is available for the liver disease in AATD. Although no specific trial has been performed, COPD in AATD should be treated as per COPD recommendations. Based on a randomized clinical trial, augmentation therapy is indicated in non-smoking adults less than 70 years of age with emphysema at chest CT, confirmed homozygous AATD, and FEV1 between 35% and 70% of predicted. In contrast Z heterozygosis (MZ or SZ) brings a risk of lung or liver disease only in association with further risk factors. Early detection, in all patients with COPD and chronic liver disease, is critical for the correct information of Z variant carriers. News ways of correcting the liver production of alpha1-antitrypsin will modify the care of AATD patients.

Hidden Comorbidities in Asthma: A Perspective for a Personalized Approach

Bronchial asthma is the most frequent inflammatory non-communicable condition affecting the airways worldwide. It is commonly associated with concomitant conditions, which substantially contribute to its burden, whether they involve the lung or other districts. The present review aims at providing an overview of the recent acquisitions in terms of asthma concomitant systemic conditions, besides the commonly known respiratory comorbidities. The most recent research has highlighted a number of pathobiological interactions between asthma and other organs in the view of a shared immunological background underling different diseases. A bi-univocal relationship between asthma and common conditions, including cardiovascular, metabolic or neurodegenerative diseases, as well as rare disorders such as sickle cell disease, α1-Antitrypsin deficiency and immunologic conditions with hyper-eosinophilia, should be considered and explored, in terms of diagnostic work-up and long-term assessment of asthma patients. The relevance of that acquisition is of utmost importance in the management of asthma patients and paves the way to a new approach in the light of a personalized medicine perspective, besides targeted therapies.

COVID-19's impact on care practice for alpha-1-antitrypsin deficiency patients

BACKGROUND

Patients with alpha-1 antitrypsin deficiency (AATD), commonly categorized as a rare disease, have been affected by the changes in healthcare management brought about by COVID-19. This study's aim was to identify the changes that have taken place in AATD patient care as a result of the COVID-19 pandemic in Spain and to propose experts' recommendations aimed at ensuring humanized and quality care for people with AATD in the post-pandemic situation.

METHODS

A qualitative descriptive case study with a holistic single-case design was conducted, using focus groups with experts in AATD clinical management, including 15 health professionals with ties to the Spanish health system (12 pneumologists and 2 hospital pharmacists from 11 different hospitals in Spain) and 1 patient representative.

RESULTS

COVID-19 has had a major impact on numerous aspects of AATD clinical patient management in Spain, including diagnostic, treatment, and follow-up phases. The experts concluded that there is a need to strengthen coordination between Primary Care and Hospital Care and improve the coordination processes across all the organizations and actors involved in the healthcare system. Regarding telemedicine and telecare, experts have concluded that it is necessary to promote this methodology and to develop protocols and training programs. Experts have recommended developing personalized and precision medicine, and patient participation in decision-making, promoting self-care and patient autonomy to optimize their healthcare and improve their quality of life. The possibility of monitoring and treating AATD patients from home has also been proposed by experts. Another result of the study was the recommendation of the need to ensure that plasma donations are made on a regular basis by a sufficient number of healthy individuals.

CONCLUSION

The study advances knowledge by highlighting the challenges faced by health professionals and changes in AATD patient management in the context of the COVID-19 pandemic. It also proposes experts' recommendations aimed at ensuring humanized and quality care for people with AATD in the post-pandemic situation. This work could serve as a reference study for physicians on their daily clinical practice with AATD patients and may also provide guidance on the changes to be put in place for the post-pandemic situation.

The impact of diagnostic delay on survival in alpha-1-antitrypsin deficiency: results from the Austrian Alpha-1 Lung Registry

BACKGROUND

Alpha-1-antitrypsin (AAT) deficiency (AATD) is a genetic disorder that can manifest as lung disease. A delay between onset of symptoms and diagnosis of AATD is common and associated with worse clinical status and more advanced disease stage but the influence on survival is unclear.

OBJECTIVE

We aimed to investigate the impact of diagnostic delay on overall survival (OS) and transplant-free survival (TS) in AATD patients.

METHODS

We analysed 268 AATD patients from the prospective multi-centre Austrian Alpha-1 Lung (AAL) Registry, employing descriptive statistics, Chi-square-test as well as univariable (Kaplan-Meier plots, log-rank test) and multivariable survival analysis (Cox regression).

RESULTS

The predominant phenotype was Pi*ZZ (82.1%). At diagnosis, 90.2% had an AAT level below 0.6 g/L. At inclusion, 28.2% had never smoked, 68.0% had quit smoking and 3.8% continued to smoke. Lung disease was diagnosed in 98.5%, thereof most patients were diagnosed with emphysema (63.8%) and/or chronic obstructive pulmonary disease (44.0%). Median diagnostic delay was 5.3 years (inter-quartile range [IQR] 2.2-11.5 years). In multivariable analysis (n = 229), a longer diagnostic delay was significantly associated with worse OS (hazard ratio [HR] 1.61; 95% CI 1.09-2.38; p = 0.016) and TS (HR 1.43; 95% CI 1.08-1.89; p = 0.011), independent from age, smoking status, body mass index (BMI), forced expiratory volume in one second (FEV₁) and long-term oxygen treatment. Furthermore, BMI, age and active smoking were significantly associated with worse OS as well as BMI, active smoking and FEV₁ were with worse TS.

CONCLUSIONS

A delayed diagnosis was associated with significantly worse OS and TS. Screening should be improved and efforts to ensure early AATD diagnosis should be intensified.

Registry-based cohort study of alpha-1 antitrypsin deficiency prevalence, incidence and mortality in Denmark 2000-2018

OBJECTIVE

To estimate the prevalence of diagnosed alpha-1 antitrypsin deficiency (dAATD) in Denmark as of 31 December 2018, and dAATD incidence and mortality from 1 January 2000 to 31 December 2018.

STUDY DESIGN AND SETTING

We used the Danish National Patient Registry to identify patients with dAATD based on the International Classification of Diseases, 10th Revision (ICD-10) code E88.0A and the Danish Civil Registration System (CRS) for population counts and vital status. We estimated dAATD prevalence, incidence and mortality. We compared mortality among patients with dAATD and an age-matched and sex-matched cohort extracted from the Danish CRS. We conducted a sensitivity analysis to examine whether coding changes during 2000-2018, from a general to a more specific ICD-10 code for AATD, and left truncation affected results appreciably.

RESULTS

The prevalence of dAATD was 12.9 (95% CI 11.9 to 13.8) per 100 000 persons. The age distribution was bimodal, with peaks at ages ≤12 and ≥45 years. The incidence rate per 100 000 person-years was 0.90 (95% CI 0.85 to 0.96), again with a bimodal age distribution. Mortality was higher for patients with dAATD than for the general population (mortality rate ratio (mRR) 4.7, 95% CI 4.1 to 5.3), especially for children (mRR 33.8, 95% CI 6.8 to 167.4). The sensitivity analysis indicated that dAATD prevalence might have been as high as 19.7 per 100 000 persons due to less specific ICD-10 coding for AATD early in the study period or 21.4 per 100 000 persons correcting for left truncation.

CONCLUSION

Diagnosed AATD was associated with increased mortality, especially for children. The finding for children was based on few deaths and had very wide 95% CIs.

Structural characterization and conformational dynamics of alpha-1 antitrypsin pathogenic variants causing alpha-1-antitrypsin deficiency

Background: Alpha-1 antitrypsin deficiency (A1ATD) is a progressive lung disease caused by inherited pathogenic variants in the SERPINA1 gene. However, their actual role in maintenance of structural and functional characteristics of the corresponding α-1 anti-trypsin (A1AT) protein is not well characterized. Methods: The A1ATD causative SERPINA1 missense variants were initially collected from variant databases, and they were filtered based on their pathogenicity potential. Then, the tertiary protein models were constructed and the impact of individual variants on secondary structure, stability, protein-protein interactions, and molecular dynamic (MD) features of the A1AT protein was studied using diverse computational methods. Results: We identified that A1ATD linked SERPINA1 missense variants like F76S, S77F, L278P, E288V, G216C, and H358R are highly deleterious as per the consensual prediction scores of SIFT, PolyPhen, FATHMM, M-CAP and REVEL computational methods. All these variants were predicted to alter free energy dynamics and destabilize the A1AT protein. These variants were seen to cause minor structural drifts at residue level (RMSD = <2Å) of the protein. Interestingly, S77F and L278P variants subtly alter the size of secondary structural elements like beta pleated sheets and loops. The residue level fluctuations at 100 ns simulation confirm the highly damaging structural consequences of all the six missense variants on the conformation dynamics of the A1AT protein. Moreover, these variants were also predicted to cause functional deformities by negatively impacting the binding energy of A1AT protein with NE ligand molecule. Conclusion: This study adds a new computational biology dimension to interpret the genotype-protein phenotype relationship between SERPINA1 pathogenic variants with its structural plasticity and functional behavior with NE ligand molecule contributing to the Alpha-1-antitrypsin deficiency. Our results support that A1ATD complications correlates with the conformational flexibility and its propensity of A1AT protein polymerization when misfolded.

Outcomes of subjects who are lean, overweight or obese with nonalcoholic fatty liver disease: A cohort study in China

The ability to determine the prognosis of lean nonalcoholic fatty liver disease (NAFLD) is essential for decision making in clinical settings. Using a large community-based Chinese cohort, we aimed to investigate NAFLD outcomes by body mass index (BMI). We used the restricted cubic splines method to investigate the dose-response relationship between BMI and outcomes in subjects with NAFLD and those without NAFLD. We included 73,907 subjects from the Kailuan cohort and grouped all subjects into four phenotypes by using NAFLD and BMI (<23 kg/m² ). The probability of developing outcomes for individuals with lean NAFLD (LN), overweight/obese NAFLD (ON), overweight/obese non-NAFLD (ONN), and lean non-NAFLD (LNN) was estimated. We found a U-shaped association between BMI and death but a linear positive association concerning cardiovascular disease (CVD) after adjusting for age and other covariates. Compared with the LNN group, the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of the LN, ON, and ONN groups were 1.30 (1.14-1.49), 0.86 (0.80-0.91), 0.84 (0.80-0.89) for all-cause death, 2.61 (1.13-6.03), 0.74 (0.44-1.26), 1.10 (0.70-1.74) for liver-related death, 2.12 (1.46-3.08), 1.23 (0.99-1.54), 1.19 (0.98-1.43) for digestive system cancers, and 2.04 (1.40-2.96), 1.30 (1.05-1.61), 1.21 (1.01-1.46) for obesity-related cancers. Subjects with LN had a significantly higher risk of colorectal cancer and esophagus cancer. However, the ON group had the highest CVD risk (HR, 1.39; 95% CI, 1.27-1.52). The LN group with hypertension had a higher risk of adverse outcomes, and those without hypertension had a similar risk compared to LNN. Conclusion: Subjects with LN may experience a higher risk of all-cause death, digestive system cancers, and obesity-related cancers than the other three groups but a lower risk of CVD than ON subjects. LN with hypertension may be a high-risk phenotype.

Lower serum alpha 1 antitrypsin levels in patients with severe COVID-19 compared with patients hospitalized due to non-COVID-19 pneumonia

INTRODUCTION

Alpha 1 antitrypsin (A1AT) is the major human blood serine protease inhibitor. Transmembrane serine protease 2 (TMPRSS2), which is crucial for SARS-CoV-2 cell entry, is inhibited by A1AT. Therefore, we hypothesized that individuals with diminished levels of A1AT may be more prone to SARS-CoV-2 infection and severe COVID-19 disease. Our aim in this study was to evaluate the level of A1AT in hospitalized COVID-19 patients in comparison to hospitalized patients with non-COVID-19 pneumonia.

METHODS

We conducted an observational prospective study between October 2020 and April 2021 in Rabin Medical Centre in Israel. A1AT levels were measured from the routine serum samples of hospitalized patients with COVID-19 and non-COVID-19 pneumonia (control group). The primary outcome was A1AT level, secondary outcomes were clinical outcomes and predictors of morality.

RESULTS

Overall, 145 patients were included in the study, 98 in the COVID-19 group and 47 in the control group. The median A1AT level was 222 mg/dL (interquartile range (IQR) 188-269) and 258 mg/dL (IQR 210-281) in the COVID-19 and control groups, respectively (p = .045). Multivariate analysis for independent risk factors for mortality among COVID-19 patients showed that diabetes mellitus (p = .02), older age (p = .04), and high A1AT levels (p = .04) were all associated with increased mortality.

CONCLUSION

Patients admitted due to severe COVID-19 had lower A1AT levels in comparison to patients admitted due to non-COVID pneumonia. This observation may suggest an association between mildly diminished A1AT and higher risk of SARS-CoV-2 infection with severe COVID-19 disease.

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.

Severe α1-antitrypsin deficiency associated with lower blood pressure and reduced risk of ischemic heart disease: a cohort study of 91,540 individuals and a meta-analysis

Background

Increased elastase activity in α₁-antitrypsin deficiency may affect elasticity of the arterial walls, and thereby blood pressure and susceptibility to cardiovascular disease. We hypothesized that severe α₁-antitrypsin deficiency is associated with reduced blood pressure and susceptibility to cardiovascular disease.

Methods

We genotyped 91,353 adults randomly selected from the Danish general population and 187 patients from the Danish α₁-Antitrypsin Deficiency Registry and recorded baseline blood pressure, baseline plasma lipids and cardiovascular events during follow-up. 185 participants carried the ZZ genotype, 207 carried the SZ genotype and 91,148 carried the MM genotype.

Results

α₁-Antitrypsin deficiency was associated with decreases in blood pressure of up to 5 mmHg for systolic blood pressure and up to 2 mmHg for diastolic blood pressure, in ZZ vs SZ vs MM individuals (trend test, P’s ≤ 0.01). Plasma triglycerides and remnant cholesterol were reduced in ZZ individuals compared with MM individuals (t-test, P’s < 0.001). α₁-Antitrypsin deficiency was associated with lower risk of myocardial infarction (trend test P = 0.03), but not with ischemic heart disease, ischemic cerebrovascular disease or hypertension (trend test, P’s ≥ 0.59). However, when results for ischemic heart disease were summarized in meta-analysis with results from four previous studies, individuals with versus without α₁-antitrypsin deficiency had an odds ratio for ischemic heart disease of 0.66 (95% CI:0.53–0.84).

Conclusions

Individuals with severe α₁-antitrypsin deficiency have lower systolic and diastolic blood pressure, lower plasma triglycerides and remnant cholesterol, reduced risk of myocardial infarction, and a 34% reduced risk of ischemic heart disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01973-3.

Recent advancements in understanding the genetic involvement of alpha-1 antitrypsin deficiency associated lung disease: a look at future precision medicine approaches

INTRODUCTION

Alpha-1 antitrypsin deficiency occurs in individuals with deleterious genetic mutations on both chromosomes (maternal and paternal) in SERPINA1, the gene encoding the alpha-1 antitrypsin protein. There has been substantial progress in understanding the genetic variation that underlies the heterogeneous penetrance of lung disease in alpha-1 antitrypsin deficiency.

AREAS COVERED

This review will cover SERPINA1 gene structure and genetic variation, population genetics, genome-wide genetic modifiers of lung disease, alternative mechanisms of disease, and emerging therapeutics - including gene and cell therapy - related to alpha-1 antitrypsin deficiency-associated lung disease.

EXPERT OPINION

There remains ample opportunity to employ precision medicine in the diagnosis, prognosis, and therapy of alpha-1 antitrypsin deficiency-associated lung disease. In particular, a genome-wide association study and subsequent polygenic risk score is an important first step in identifying genome-wide genetic modifiers contributing to the variability of lung disease in severe alpha-1 antitrypsin deficiency.

Alpha-1 Antitrypsin and Hepatocellular Carcinoma in Liver Cirrhosis: SERPINA1 MZ or MS Genotype Carriage Decreases the Risk

Heterozygotes for Z or S alleles of alpha-1-antrypsin (AAT) have low serum AAT levels. Our aim was to compare the risk of hepatocellular carcinoma (HCC) in patients with liver cirrhosis carrying the SERPINA1 MM, MZ and MS genotypes. The study groups consisted of 1119 patients with liver cirrhosis of various aetiologies, and 3240 healthy individuals served as population controls. The MZ genotype was significantly more frequent in the study group (55/1119 vs. 87/3240, p < 0.0001). The MS genotype frequency was comparable in controls (32/119 vs. 101/3240, p = 0.84). MZ and MS heterozygotes had lower serum AAT level than MM homozygotes (medians: 0.90 g/L; 1.40 g/L and 1.67 g/L; p < 0.001 for both). There were significantly fewer patients with HCC in the cirrhosis group among MZ and MS heterozygotes than in MM homozygotes (5/55 and 1/32 respectively, vs. 243/1022, p < 0.01 for both). The risk of HCC was lower in MZ and MS heterozygotes than in MM homozygotes (OR 0.3202; 95% CI 0.1361–0.7719 and OR 0.1522; 95% CI 0.02941–0.7882, respectively). Multivariate analysis of HCC risk factors identified MZ or MS genotype carriage as a protective factor, whereas age, male sex, BMI and viral aetiology of cirrhosis increased HCC risk.

The spectrum of clinical sequelae associated with alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin (AAT) deficiency (AATD) is an autosomal co-dominant condition that predisposes to the development of lung disease, primarily emphysema. Emphysema results from the breakdown of lung matrix elastin by proteases, including neutrophil elastase, a protease normally inhibited by AAT. AATD also predisposes to liver (cirrhosis) and skin (panniculitis) disease, and to vasculitis. The prevalence of AATD is estimated to be approximately 1 in 3,500 individuals in the United States. However, lack of awareness of AATD among some physicians, misperceptions regarding the absence of effective therapy, and the close overlap in symptoms with asthma and non-AATD chronic obstructive pulmonary disease are thought to contribute to under-recognition of the disease. In patients with AATD, treatment with intravenous AAT augmentation therapy is the only currently available treatment known to slow the progression of emphysema. Moreover, smoking cessation and other lifestyle interventions also help improve outcomes. Early diagnosis and intervention are of key importance due to the irreversible nature of the resultant emphysema. Liver disease is the second leading cause of death among patients with AATD and a minority of patients present with panniculitis or antineutrophil cytoplasmic antibody-associated vasculitis, thought to be directly related to AATD. Though no randomized trial has assessed the effectiveness of augmentation therapy for AATD-associated panniculitis, clinical experience and case series suggest there is a benefit. Other diseases putatively linked to AATD include aneurysmal disease and multiple neurological conditions, although these associations remain speculative in nature.

Chronic Obstructive Pulmonary Disease: Epidemiology, Biomarkers, and Paving the Way to Lung Cancer

Chronic obstructive pulmonary disease (COPD), the frequently fatal pathology of the respiratory tract, accounts for half a billion cases globally. COPD manifests via chronic inflammatory response to irritants, frequently to tobacco smoke. The progression of COPD from early onset to advanced disease leads to the loss of the alveolar wall, pulmonary hypertension, and fibrosis of the respiratory epithelium. Here, we focus on the epidemiology, progression, and biomarkers of COPD with a particular connection to lung cancer. Dissecting the cellular and molecular players in the progression of the disease, we aim to shed light on the role of smoking, which is responsible for the disease, or at least for the more severe symptoms and worse patient outcomes. We summarize the inflammatory conditions, as well as the role of EMT and fibroblasts in establishing a cancer-prone microenvironment, i.e., the soil for ‘COPD-derived’ lung cancer. We highlight that the major health problem of COPD can be alleviated via smoking cessation, early diagnosis, and abandonment of the usage of biomass fuels on a global basis.

Severe alpha-1-antitrypsin deficiency increases the risk of venous thromboembolism

BACKGROUND

Severe alpha-1-antitrypsin deficiency (AATD), phenotype PiZZ, is associated with increased risk of liver disease and chronic obstructive pulmonary disease (COPD), but the risk of venous thromboembolism (VTE) is unknown. Our aim was to evaluate the risk of VTE in individuals with severe AATD compared with control subjects from the general population.

METHODS

Individuals with severe AATD (n = 1577) were recruited from the Swedish national AATD register. Control subjects (n = 5969) were selected from the OLIN (Obstructive Lung Disease in Northern Sweden) studies, that include a random general population sample. Longitudinal data on VTE and diagnoses were obtained from the Swedish National Patient Registry. Associations were analyzed using multivariable Cox regression.

RESULTS

At inclusion, 46% of the AATD individuals and 53% of the controls were never-smokers. COPD was present in 46% of the AATD individuals compared with 4% of the controls. During a median follow-up of 18 years, 116 (7%) of the AATD individuals and 89 (1%) of the control subjects developed VTE, unadjusted hazard ratio 6.5 (95% confidence interval 4.9-8.6). Risk factors for incident VTE were male gender, age, COPD, cancer, and liver disease. Adjusting for these factors, the AATD individuals had a significantly higher risk of incident VTE, adjusted hazard ratio 4.2 (95% confidence interval 2.9-6.2) as compared with the controls.

CONCLUSION

Subjects with severe AATD have considerably increased risk of developing VTE compared with the general population, even after accounting for risk factors. This calls for optimized risk factor management and clinical follow-up of this patient group.

Hepatic and Extrahepatic Sources and Manifestations in Endoplasmic Reticulum Storage Diseases

Alpha-1-antitrypsin (AAT) and fibrinogen are secretory acute phase reactant proteins. Circulating AAT and fibrinogen are synthesized exclusively in the liver. Mutations in the encoding genes result in conformational abnormalities of the two molecules that aggregate within the rough endoplasmic reticulum (RER) instead of being regularly exported. That results in AAT-deficiency (AATD) and in hereditary hypofibrinogenemia with hepatic storage (HHHS). The association of plasma deficiency and liver storage identifies a new group of pathologies: endoplasmic reticulum storage disease (ERSD).

Alpha-1 Antitrypsin Deficiency-Associated Clinical Manifestations and Healthcare Resource Use in the United States

Pulmonary events (PEs) associated with alpha-1 antitrypsin deficiency (AATD) can have a severe clinical course and increase healthcare resource use (HRU). However, AATD-associated HRU and healthcare costs have not been extensively described. This study describes and compares real-world HRU and healthcare costs among US patients with severe (requiring hospitalization after AATD-related PE) versus nonsevere AATD clinical course. Administrative healthcare claims for patients with a second primary AATD diagnosis between 6/1/2008 and 12/31/2017 were analyzed from 2 databases (requiring continuous enrollment 6 months preceding diagnosis). Patient baseline characteristics and AATD-associated PE incidence rates, HRU, and healthcare costs during follow-up were compared in patients with severe versus nonsevere AATD. Of 5109 patients with a second AATD diagnosis, 2674 (severe, n = 711 [26.6%]; nonsevere, n = 1963 [73.4%]) had ≥1 AATD-associated PE. PE incidence per 100 person-years was higher in patients with severe versus nonsevere AATD. Annual incidences (mean ± SD) of emergency department (1.2 ± 5.7 vs. 0.4 ± 1.2), inpatient (1.3 ± 2.5 vs. 0.1 ± 0.5), and outpatient (10.3 ± 15.9 vs. 5.7 ± 13.2) visits were higher in patients with severe versus nonsevere AATD. Median (interquartile range) annual costs were also higher for patients with severe versus nonsevere AATD for emergency department ($185 [$0-$1665] vs. $0 [$0-$264]), inpatient ($16,038 [$2968-$70,941] vs. $0 [$0-$0]), and outpatient ($2663 [$412-$10,277] vs. $1114 [$134-$4195]) visits. Higher percentages of patients with severe AATD were prescribed augmentation therapy, antibiotics, or corticosteroids. These findings suggest that patients with severe AATD have higher incidence of AATD-associated PEs, as well as higher HRU and healthcare costs.

Nephrotic syndrome secondary to alpha-1 antitrypsin deficiency

We report a 64-year-old caucasian woman diagnosed with membranous nephropathy secondary to alpha-1 antitrypsin deficiency (AATD). AATD is a rare autosomal codominant genetic disorder. Its clinical manifestations are mostly observed in the lungs, with early-onset emphysema. Nephropathy due to AATD is still very rare and only a few cohort studies have been reported. It has been recognised that alpha-1 antitrypsin has a protective role in the kidneys which enhances the possibility of development of kidney failure, such as nephrotic syndrome, in cases of AATD. Further clinical investigation is needed to understand the relationship between the development of nephropathy, namely membranous nephropathy, and AATD.

Host genomics of COVID-19: Evidence point towards Alpha 1 antitrypsin deficiency as a putative risk factor for higher mortality rate

Corona Virus Disease 2019 (COVID-19) has emerged as a pandemic leading to unprecedented disruption of global health and economy. Transmembrane protease serine 2 (TMPRSS2) has been found to be critical in priming the viral spike protein and the host ACE2 receptor before the virus enters into the host cell. Recent studies have experimentally demonstrated that Alpha 1 antitrypsin (encoded by SERPINA1 gene) is an inhibitor of TMPRSS2 and provided support to the already approved therapy as a candidate for COVID-19. Interestingly Alpha 1 antitrypsin deficiency is common among Europeans. Here we have provided in silico evidence that Alpha 1 antitrypsin can interact with TMPRSS2 and both of them are co-expressed in the human liver and lung. We then analyzed the gnomAD dataset to show that Europeans and Latinos have a substantially higher carrier frequency of Alpha 1 Antitrypsin Deficiency (~12%) compared to other large ethnicities. Therefore, we hypothesize that Alpha 1 antitrypsin deficiency might be a risk factor for severe infection with SARS-CoV-2. We propose Alpha 1 antitrypsin status as a potential prognostic predictor of COVID-19 outcome.

Alpha1-antitrypsin deficiency and asthma

PURPOSE OF REVIEW

The aim of the article is to highlight the association between α1-antitrypsin deficiency (AATD) and asthma.

RECENT FINDINGS

AATD is one of the most common and underrecognized autosomal disorders associated with an increased risk of developing liver and lung diseases. An association between α1-antitrypsin and asthma has been suggested, especially with severe forms of this disease. Many studies have shown an increased prevalence of asthma in the α1-antitrypsin-deficient population overtime (4-38%). The biological mechanism underlying these two conditions and able to bind them has not yet been well investigated. As α1-antitrypsin is the main inhibitor of the serine proteinase and it is an important anti-inflammatory protein with pronounced immunomodulatory activities, it can be hypothesized that the link between AATD and asthma might be represented by the elastase/antielastase imbalance and the proinflammatory effect that occurs because of the reduction of this protein.

SUMMARY

There is a strong need for further researches to better understand the molecular mechanisms binding AATD and asthma. It is also recommendable to screen for AATD, late-onset asthma patients, and/or those with not fully reversible airways obstruction.

Exacerbations of Lung Disease in Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is an important risk factor for development of chronic obstructive pulmonary disease (COPD). Patients with AATD classically develop a different pattern of lung disease from those with usual COPD, decline faster and exhibit a range of differences in pathogenesis, all of which may be relevant to phenotype and/or impact of exacerbations. There are a number of definitions of exacerbation, with the main features being worsening of symptoms over at least 2 days, which may be associated with a change in treatment. In this article we review the literature surrounding exacerbations in AATD, focusing, in particular, on ways in which they may differ from such events in usual COPD, and the potential impact on clinical management.

Combined liver-kidney transplantation for rare diseases

Combined liver and kidney transplantation (CLKT) is indicated in patients with failure of both organs, or for the treatment of end-stage chronic kidney disease (ESKD) caused by a genetic defect in the liver. The aim of the present review is to provide the most up-to-date overview of the rare conditions as indications for CLKT. They are major indications for CLKT in children. However, in some of them (e.g., atypical hemolytic uremic syndrome or primary hyperoxaluria), CLKT may be required in adults as well. Primary hyperoxaluria is divided into three types, of which type 1 and 2 lead to ESKD. CLKT has been proven effective in renal function replacement, at the same time preventing recurrence of the disease. Nephronophthisis is associated with liver fibrosis in 5% of cases and these patients are candidates for CLKT. In alpha 1-antitrypsin deficiency, hereditary C3 deficiency, lecithin cholesterol acyltransferase deficiency and glycogen storage diseases, glomerular or tubulointerstitial disease can lead to chronic kidney disease. Liver transplantation as a part of CLKT corrects underlying genetic and consequent metabolic abnormality. In atypical hemolytic uremic syndrome caused by mutations in the genes for factor H, successful CLKT has been reported in a small number of patients. However, for this indication, CLKT has been largely replaced by eculizumab, an anti-C5 antibody. CLKT has been well established to provide immune protection of the transplanted kidney against donor-specific antibodies against class I HLA, facilitating transplantation in a highly sensitized recipient.

Comorbidity Associations with AATD Among Commercially Insured and Medicare Beneficiaries with COPD in the US

Introduction

Alpha-1 antitrypsin deficiency (AATD) is often not identified in patients with chronic obstructive pulmonary disease (COPD) until advanced stages of disease, despite the availability of genetic testing. While clinical practice guidelines provide recommendations on patients who should be tested, more refined algorithms are needed to identify COPD patients who are likely candidates for AATD testing and to prevent delays in diagnosis and treatment. The objective of this study was to identify comorbid associations with AATD among patients diagnosed with COPD in the United States.

Methods

Using data from the 2012–2017 PharMetrics Plus Administrative Claims Database and 2011–2014 Medicare Fee for Service 5% Sample, patients with COPD (ICD-9-CM: 491.xx, 492.xx, or 496, ICD-10-CM J41, J42, J43, J44) and AATD (ICD-9-CM: 273.4, ICD-10-CM: E88.01) were identified. Patient demographic and diagnostic characteristics were assessed. Logistic regression models were developed to identify significant predictors of AATD.

Results

A cohort of 344,528 Medicare beneficiaries with COPD (of which 302 (0.09%) also had two diagnoses of AATD) and a cohort of 340,259 commercially insured patients with COPD (of which 1076 (0.3%) also had a diagnosis of AATD) were constructed. Associations with AATD identified in both models included ICD-9-CM and ICD-10-CM codes for chronic pulmonary heart disease, chronic liver disease and cirrhosis, and liver transplant.

Discussion

Significant associations with a diagnosis of AATD among patients with COPD were consistently represented in each of the datasets evaluated, which suggests meaningful comorbidity implications in AATD patients. These findings reinforce the need to test individuals with COPD for AATD as early as possible to help reduce the development of associated comorbid conditions.

Paediatric cholestatic liver disorders for the adult gastroenterologist: a practical guide

With improvements in the outcomes for cholestatic liver diseases that present in childhood, increasing numbers of patients will require ongoing care as adults. The recent advances in management options coupled with the fact that each adult physician will have a limited number of patients with these conditions means there is a need for those in adult services to develop expertise in these conditions that were historically the domain of paediatrics. This review provides an overview of the most common paediatric cholestatic liver diseases and outlines the clinical manifestations and potential complications, and identifies key management issues unique to each condition for effective ongoing care of these patients.

Decreased Risk of Ischemic Heart Disease in Individuals with Severe Alpha 1-Antitrypsin Deficiency (PiZZ) in Comparison with the General Population

Background

Severe alpha-1-antitrypsin deficiency (AATD) is an established risk factor for chronic obstructive pulmonary disease (COPD) and liver disease, but the effect on the incidence of ischemic heart disease (IHD) is not well known. The aim was to evaluate the risk of incident IHD in patients with severe AATD compared with a random sample of the general population, with known smoking habits.

Methods

AAT-deficient individuals, phenotype PiZZ (n=1545), were included in the Swedish National AATD Register. Controls (n=5883) were selected from population-based cohorts in Northern Sweden. Data on IHD and comorbidities were obtained by nationwide cross-linkage with the Swedish National Patient Register. Risk factors for incident IHD were analyzed using Cox regression, adjusted for age, gender, smoking status and the presence of COPD, hypertension, hyperlipidemia and diabetes.

Results

At inclusion, 46% of the PiZZ individuals and 53% of the controls were never-smokers. During follow-up (median 16 years; range 0.2–23), 8% (n=123) of PiZZ individuals and 12% (n=690) of controls developed IHD. The controls had a significantly higher risk for incident IHD than the PiZZ individuals, with adjusted hazard ratio (HR) of 1.8 (95% CI 1.4–2.3). The risk was higher for controls in both ever-smokers (HR 2.1; 95% CI 1.5–2.9) and never-smokers (HR 1.5; 95% CI 1.1–2.2).

Conclusion

PiZZ individuals have a lower risk of developing incident ischemic heart disease than the control subjects with known smoking habits, who had been randomly selected from population-based cohorts.

Reduced 25(OH) Vitamin D Association with Lower Alpha-1-Antitrypsin Blood Levels in Type 2 Diabetic Patients

Introduction: Reduced circulating levels of 25(OH)VD are associated with an increased incidence of chronic lung diseases. Alpha-1-antitrypsin (AAT) is needed to maintain healthy lung function.Objective: This study examined the hypothesis that circulating levels of AAT are lower in adult type 2 diabetic patients and that a positive association exists between circulating AAT levels and 25(OH)VD levels in these patients.Methods: Fasting blood was obtained after written informed consent from type 2 diabetic patients (n = 80) and normal siblings or volunteers (n = 22) attending clinics at LSUHSC according to the protocol approved by the Institutional Review Board for Human studies. Plasma AAT and 25(OH)VD levels were determined using ELISA kits. HbA_1c levels and chemistry profiles were analyzed at the clinical laboratory of LSUHSC hospital.Results: ATT and 25(OH)VD levels were significantly lower in type 2 diabetic patients compared with those of age-matched healthy controls. There was a significant positive correlation between 25(OH)VD and ATT deficiency. AAT levels showed significant positive correlation with HDL cholesterol levels in type 2 diabetic patients. There was no correlation between AAT levels and those of HbA_1c or with the duration of diabetes of T2D patients.Conclusions: These results suggest that 25(OH)VD deficiency may predispose type 2 diabetic patients to AAT deficiency. Whether reduced levels of circulating AAT indeed contribute to the increased risk for lung dysfunction in subjects with type 2 diabetes needs further investigation.

Immunosuppressive Drugs Alter α1-Antitrypsin Production in Hepatocytes: Implications for Epithelial Gap Repair

Immunosuppressive drugs are an inherent component of hematopoietic stem cell transplantation (HSCT) for the prevention of acute graft-versus-host disease (GVHD). Circulating α1-antitrypsin (AAT), a serine-protease inhibitor produced predominantly by hepatocytes that rises during acute phase responses, is lost in patient's stool due to gastrointestinal GVHD, and its augmentation has been found to attenuate GVHD. Here we explored the effect of immunosuppressive drugs on hepatocyte production of AAT and intestinal epithelial gap repair. The effect of commonly used immunosuppressants on AAT production was examined in vitro using HepG2 cells and primary mouse hepatocytes, and their impact on human intestinal epithelial cell line gap repair was evaluated. Sera from 12 allogeneic HSCT recipients, obtained at 14 days post-transplantation, predating the diagnosis of GVHD (n = 6), were examined for reepithelialization, with added clinical-grade AAT. Rapamycin compromised AAT production under inflammatory conditions. Mycophenolate mofetil and cyclosporine A (CSA) inhibited reepithelialization; AAT minimized the effect of CSA. Patient sera displayed superior gap repair with exogenous AAT. Functional insufficiency in circulating AAT may be the result of drug toxicities leading to ineffective gut reepithelization and compromised gut lining. Taken together, our data strengthen the rationale for incorporating AAT augmentation therapy into immunosuppressive treatment protocols.

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.

Protein phosphatase 2A (PP2A): a key phosphatase in the progression of chronic obstructive pulmonary disease (COPD) to lung cancer

Lung cancer (LC) has the highest relative risk of development as a comorbidity of chronic obstructive pulmonary disease (COPD). The molecular mechanisms that mediate chronic inflammation and lung function impairment in COPD have been identified in LC. This suggests the two diseases are more linked than once thought. Emerging data in relation to a key phosphatase, protein phosphatase 2A (PP2A), and its regulatory role in inflammatory and tumour suppression in both disease settings suggests that it may be critical in the progression of COPD to LC. In this review, we uncover the importance of the functional and active PP2A holoenzyme in the context of both diseases. We describe PP2A inactivation via direct and indirect means and explore the actions of two key PP2A endogenous inhibitors, cancerous inhibitor of PP2A (CIP2A) and inhibitor 2 of PP2A (SET), and the role they play in COPD and LC. We explain how dysregulation of PP2A in COPD creates a favourable inflammatory micro-environment and promotes the initiation and progression of tumour pathogenesis. Finally, we highlight PP2A as a druggable target in the treatment of COPD and LC and demonstrate the potential of PP2A re-activation as a strategy to halt COPD disease progression to LC. Although further studies are required to elucidate if PP2A activity in COPD is a causal link for LC progression, studies focused on the potential of PP2A reactivating agents to reduce the risk of LC formation in COPD patients will be pivotal in improving clinical outcomes for both COPD and LC patients in the future.

Managing the Alpha-1 patient in the ICU: Adapting broad critical care strategies in AATD

Alpha-1 Antitrypsin Deficiency (AATD) is a progressive pulmonary disease under-recognized or misdiagnosed by clinicians. Patients with AATD can develop a variety of organ-specific complications and as a result, often require hospitalization and treatment within critical care and ICU settings. Due to the complexity of AATD there are minimal guidelines in place to address the specific and highly variable needs of these patients in the critical care setting. This review presents clinical considerations with respect to the management of patients with AATD and provides treatment recommendations for these patients in the critical care setting. In addition, we have outlined certain aspects of the care of this patient population that may be of interest to critical care practitioners. With greater disease awareness and earlier diagnosis the onset of symptoms can be delayed, which will ultimately reduce the frequency of deleterious health consequences.

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.

Trends of testing for and diagnosis of α1-antitrypsin deficiency in the UK: more testing is needed

α₁-antitrypsin deficiency (AATD) significantly increases the risk of developing chronic obstructive pulmonary disease (COPD), and testing of all COPD patients for AATD is recommended by the World Health Organization, European Respiratory Society and Global Initiative for Chronic Obstructive Lung Disease (GOLD). We aimed to determine trends for testing and diagnosing AATD from 1990 to 2014.This study analysed all patients diagnosed with COPD from about 550 UK Optimum Patient Care Research Database general practices, including a subgroup of those diagnosed before the age of 60 years.We identified 107 024 COPD individuals, of whom 29 596 (27.6%) were diagnosed before 60 years of age. Of them, only 2.2% (95% CI 2.09-2.43%) had any record of being tested for AATD. Of those tested, 23.7% (95% CI 20.5-27.1%) were diagnosed with AATD. Between 1994 and 2013 the incidence of AATD diagnosis generally increased. A diagnosis of AATD was associated with being male, being an ex-smoker, more severe COPD with a lower forced expiratory volume in 1 s % pred and higher GOLD 2017 stages (all p<0.05).Despite an increase in the frequency of AATD testing since 1990, only 2.2% of patients diagnosed with COPD before the age of 60 years were tested. AATD prevalence was 23.7% in those tested. Thus, it appears that AATD remains markedly underdiagnosed in COPD patients.

Alpha-1-Antitrypsin Deficiency: Disease Management and Learning from Studies

Alpha-1-antitrypsin deficiency (AATD) is one of the most frequent genetic causes of liver and lung diseases. Despite its known association with chronic obstructive pulmonary disease (COPD), AATD is largely unrecognised and underdiagnosed. Cases of AATD exist within every COPD or spirometry population but must be actively investigated. AATD is a laboratory diagnosis that must be confirmed by a blood test. A number of clinical 'clues' can raise suspicion of AATD, potentially facilitating earlier diagnosis and initiation of appropriate treatment. Alpha-1-antitrypsin augmentation therapy has a clear role in patients with severe AATD and a FEV₁ ≤65% predicted. Emerging evidence suggests that attenuating the decline in lung density may prolong the time to respiratory failure.

An Epidemiological Overview of Chronic Obstructive Pulmonary Disease: What Can Real-Life Data Tell Us about Disease Management?

Chronic obstructive pulmonary disease (COPD) is a common condition, associated with increasing age and smoking exposure. COPD is a leading cause of morbidity, mortality and health care expenditure worldwide; yet, only 10-15% of all cases are identified medically. Alpha-1-antitrypsin deficiency (AATD) is responsible for about 1% of COPD cases but is also largely under-recognised, leading to diagnostic delay and missed treatment opportunities in patients who remain undetected. New evidence has recently highlighted the extent of overlap between COPD and bronchiectasis and the implications of comorbidity on clinical course and mortality. COPD with comorbid bronchiectasis deserves to be given research priority. This article overviews the epidemiology of COPD and examines the implications of overlap between COPD and AATD and between COPD and bronchiectasis.