Indications for active case searches and intravenous alpha-1 antitrypsin treatment for patients with alpha-1 antitrypsin deficiency chronic pulmonary obstructive disease: an update

Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin deficiency (AATD) is a relatively rare genetic disorder, inherited in an autosomal codominant manner, that results in reduced serum AAT concentrations, with a consequent reduction in antielastase activity in the lungs, as well as an increased risk of diseases such as pulmonary emphysema, liver cirrhosis, and necrotizing panniculitis. It results from different mutations in the SERPINA1 gene, leading to changes in the AAT glycoprotein, which can alter its concentration, conformation, and function. Unfortunately, underdiagnosis is quite common; it is possible that only 10% of cases are diagnosed. The most common deficiency is in the Z variant, and it is estimated that more than 3 million people worldwide have combinations of alleles associated with severe AATD. Serum AAT concentrations should be determined, and allelic variants should be identified by phenotyping or genotyping. Monitoring lung function, especially through spirometry, is essential, because it provides information on the progression of the disease. Although pulmonary densitometry appears to be the most sensitive measure of emphysema progression, it should not be used in routine clinical practice to monitor patients. In general, the treatment is similar to that indicated for patients with COPD not caused by AATD. Exogenous administration of purified human serum-derived AAT is the only specific treatment approved for AATD in nonsmoking patients with severe deficiency (serum AAT concentration of < 57 mg/dL or < 11 µM), with evidence of functional loss above the physiological level.

Hospital Admission Trends in Alpha-1-Antitrypsin Deficiency: A Sex-Based Analysis from the Spanish National Discharge Database, 2016-2022

Objectives: To analyze the number and clinical characteristics of hospital admissions in Spain between 2016 and 2022 in which alpha-1-antitrypsin deficiency (AATD) was coded; to describe and analyze differences in these parameters between men and women; and to identify variables associated with a worse prognosis. Methods: We used a nationwide discharge database to select all admissions featuring an AATD diagnostic code (ICD-10 code E88.01) in any position. Results: We found 5142 hospital admissions with a diagnosis of AATD and detected a significant increase in their number from 2016 to 2022 (p = 0.034 for trend). Males accounted for 58.21% of the hospitalizations and had a higher Charlson Comorbidity Index than women (1.86 vs. 1.33; p < 0.001), were hospitalized more frequently (21.18% of men were hospitalized more than once vs. 17.76% of women, p < 0.001), and had a higher probability of severe disease (OR 1.39; 95%CI 1.10-1.75). Crude in-hospital mortality (IHM) was 6.85% in men and 4.8% in women (p = 0.007). The variables associated with IHM in both sexes were older age, more hospital admissions, and liver disease or lung cancer. Invasive and non-invasive mechanical ventilation and admission to the ICU were also associated with IHM in men and women. Multivariable adjustment revealed no association between sex and IHM. Conclusions: The number of hospitalizations for AATD increased in Spain from 2016 to 2022. Men represented almost 60% of hospitalizations, were admitted more frequently and with more comorbidities, and had a higher probability of severe disease than women. There was no association between sex and IHM.

Assessment and monitoring of lung disease in patients with severe alpha 1 antitrypsin deficiency: a european delphi consensus of the EARCO group

BACKGROUND

Currently, there is conflicting information and guidance on the effective management of Alpha 1 Antitrypsin Deficiency (AATD). Establishing a consensus of assessment and disease management specific to AATD is important for achieving a standardized treatment pathway and for improving patient outcomes. Here, we aim to utilize the Delphi method to establish a European consensus for the assessment and management of patients with severe AATD.

METHODS

Two rounds of a Delphi survey were completed online by members of the European Alpha-1 Research Collaboration (EARCO). Respondents were asked to indicate their agreement with proposed statements for patients with no respiratory symptoms, stable respiratory disease, and worsening respiratory disease using a Likert scale of 1-7. Levels of agreement between respondents were calculated using a weighted average.

RESULTS

Round 1 of the Delphi survey was sent to 103 members of EARCO and 38/103 (36.9%) pulmonologists from across 15 countries completed all 109 questions. Round 2 was sent to all who completed Round 1 and 36/38 (94.7%) completed all 79 questions. Responses regarding spirometry, body plethysmography, high-resolution computed tomography, and the initiation of augmentation therapy showed little variability among physicians, but there was discordance among other aspects, such as the use of low-dose computed tomography in both a research setting and routine clinical care.

CONCLUSIONS

These results provide expert opinions for the assessment and monitoring of patients with severe AATD, which could be used to provide updated recommendations and standardized treatment pathways for patients across Europe.

Detection of Alpha-1 Antitrypsin Levels in Chronic Obstructive Pulmonary Disease in Respiratory Clinics in Spain: Results of the EPOCONSUL 2021 Audit

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is an underdiagnosed condition despite being one of the most common inherited disorders in adults that is associated with an increased risk of developing chronic obstructive pulmonary disease (COPD). The aim was to evaluate the frequency of performing AAT levels and associated factors in COPD patients in an audit conducted in 2021-2022, as well as to compare with a previous audit conducted in 2014-2015.

METHODS

EPOCONSUL 2021 is a cross-sectional audit that evaluated the outpatient care provided to COPD patients in respiratory clinics in Spain based on available data from medical registries.

RESULTS

4225 patients with a diagnosis of COPD from 45 centers were audited in 2021. A total of 1670 (39.5%) patients underwent AAT determination. Being treated at a specialized COPD outpatient clinic (OR 1.88, p = 0.007), age ≤ 55 years old (OR 1.84, p = 0.007) and a FEV1 < 50% (OR 1.86, p < 0.001) were associated with a higher likelihood of being tested for AAT, while Charlson index ≥ 3 (OR 0.63, p < 0.001) and genotyping of AATD availability (OR 0.42, p < 0.001) showed a statistically significant negative association. The analysis of cases included in respiratory units that participated in both audits showed an increase in the proportion of cases with AAT serum level testing available (adjusted OR 2.81, p < 0.001). The percentage of individuals with serum AAT levels < 60 mg/dL (a severe AATD) was 4%.

CONCLUSIONS

Our analysis identifies significant improvements in adherence to the recommendation to test AAT levels in COPD patients, performed in 4 out of 10 patients, being more likely at younger ages and with higher COPD severity, and with a detection of severe AATD of 4% among those tested, suggesting that clinicians still perform AAT testing in COPD patients selectively. Therefore, efforts are still needed to optimize AATD screening and establish new early detection strategies to reduce morbidity and mortality in these patients.

Personalised indication of augmentation therapy for emphysema associated with severe alpha-1 antitrypsin deficiency: a case series

Severe alpha-1 antitrypsin deficiency (AATD) is associated with an increased risk of emphysema. However, the clinical manifestations are very heterogeneous, and an individual prognosis is very difficult to establish. Intravenous augmentation therapy with alpha-1 antitrypsin (AAT) from pooled blood donors is the only specific treatment available, but it requires weekly or biweekly administration for life. Several guidelines provide the indication criteria for the initiation of AAT augmentation therapy. However, in clinical practice, there are situations in which the decision as to when to start treatment becomes uncertain and some studies have shown great variability in the indication of this treatment even among specialists. The usual dilemma is between initiating augmentation therapy in individuals who may not develop significant lung disease or in whom disease will not progress or delaying it in patients who may otherwise rapidly and irreversibly progress. We illustrate this dilemma with five clinical cases: from the case of a patient with normal lung function who requests initiation of therapy to a moderately stable patient without augmentation or a mild patient who, after several years of remaining stable without treatment, deterioration in lung function initiated and, consequently, augmentation therapy was begun. All the nuances associated with the indication of augmentation justify a personalised approach and the decision about initiating augmentation therapy must be made after careful consideration of the pros and cons with the patient in reference centres with experience in treatment. These reference centres can work in collaboration with local hospitals where patients can be closely followed and augmentation therapy can be administered to avoid unnecessary travelling, making periodical administrations more comfortable for the patient.

Nine controversial questions about augmentation therapy for alpha-1 antitrypsin deficiency: a viewpoint

Augmentation therapy with intravenous alpha-1 antitrypsin is the only specific treatment for alpha-1 antitrypsin deficiency (AATD)-associated emphysema. This treatment has been available and remained basically unchanged for more than 35 years, but many questions persist regarding its indications, regimen of administration and efficacy. Because AATD is a rare disease, it has not been possible to conduct randomised, placebo-controlled trials that are adequately powered for the usual outcomes analysed in non-AATD-related COPD, such as lung function decline, exacerbations, symptoms or quality of life. New outcomes such as lung densitometry measured by computed tomography are more sensitive for identifying emphysema progression but are not widely accepted by regulatory agencies. In addition, clinical manifestations, severity and the natural history of lung disease associated with AATD are very heterogeneous, which means that individual prediction of prognosis is challenging. Therefore, the indication for augmentation is sometimes a dilemma between initiating treatment in individuals who may not develop significant lung disease or in whom disease will not progress and delaying it in patients who will otherwise rapidly and irreversibly progress.Other areas of debate are the possible indication for augmentation in patients with severe AATD and respiratory diseases other than emphysema, such as bronchiectasis or asthma, and the use of therapy after lung transplant in AATD patients. All these uncertainties imply that the indication for treatment must be personalised in expert reference centres after in-depth discussion of the pros and cons of augmentation with the patient.

An Alpha-1 Antitrypsin Deficiency Screening Study in Patients with Chronic Obstructive Pulmonary Disease, Bronchiectasis, or Asthma in Turkey

Purpose

Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition characterized by decreased serum alpha-1 antitrypsin (AAT) levels. We aim to identify AATD in patients with chronic obstructive pulmonary disease (COPD), bronchiectasis, or asthma and to report the frequency of AAT variants in Turkey.

Patients and Methods

This non-interventional, multicenter, prospective study was conducted between October 2021 and June 2022. Adult patients with COPD, bronchiectasis, asthma, liver symptoms, or family members with AATD were included. Demographic and clinical characteristics, pulmonary diagnosis, respiratory symptoms, and AAT serum levels were assessed. Whole blood samples were collected as dried blood spots, and the most common AATD mutations were simultaneously tested by allele-specific genotyping.

Results

A total of 1088 patients, mainly diagnosed with COPD (92.7%) and shortness of breath (78.7%), were assessed. Fifty-one (5%) were found to have AATD mutations. Fifteen (29.4%) patients had Pi*S or Pi*Z mutations, whereas 36 (70.6%) patients carried rare alleles Pi*M malton (n=18, 35.3% of mutations), Pi*I (n=8, 16%), Pi*P lowell (n=7, 14%), Pi*M heerlen (n=2, 4%), and Pi*S iiyama (n=1, 2%). The most common heterozygous combinations were Pi*M/Z (n=12, 24%), and Pi*M/M malton (n=11, 22%). Ten patients with severe AATD due to two deficiency alleles were identified, two with the Pi*Z/Z genotype, four with the genotype Pi*M malton/M malton, three with Pi*Z/M malton, and one with Pi*Z/M heerlen.

Conclusion

Our results identified AATD mutations as a genetic-based contributor to lung disease in patients with COPD or bronchiectasis and assessed their frequency in a population of Turkish patients.

Recommendations for the Implementation of the Self-Administration of Alpha-1 Antitrypsin

Purpose

Administration of exogenous alpha-1 antitrypsin (AAT) is the only specific therapy for the management of pulmonary morbidity in patients with AAT deficiency. It requires weekly or biweekly intravenous infusions, which may impact patient independence and quality of life. Self-administration of AAT therapy is an alternative to reduce the burden for patients who require AAT therapy. We presented herein experts' recommendations for the implementation of a program for the self-administration of AAT.

Methods

This project was conducted using a modified nominal group technique and was undertaken in two online meetings involving the participation of 25 experts: specialists in pulmonology (n=17), nurses (n=5) and hospital pharmacists (n=3).

Results

The following issues were discussed, and several recommendations were agreed upon on the following topics: a) patient profile and clinical evaluation, establishing selection criteria that should include clinical as well as social criteria; b) role of health care professionals, suggested roles for specialists in pulmonology, nurses, and hospital pharmacists; c) training by the nurse, including recommendations before initiating the training and the content of the training sessions; and d) logistic issues and follow-up, adherence, and patient support.

Conclusion

We expect this proposal to increase awareness of this therapeutic alternative and facilitate the implementation of self-administration programs, thus contributing to optimizing the patient experience with AAT therapy. Further research on the outcomes of these programs, especially from the patient perspective, will also help to improve their design and implementation.

[Results of the Implementation of a Case-Finding Program for Alpha-1 Antitrypsin Deficiency in COPD Patients]

Objectives

Currently, the identification of new cases of alpha-1 antitrypsin deficiency (AATD) continues to be one of the great challenges facing the disease. The present study aims to perform an analysis of the results of the implementation of a systematic case detection program of AATD for patients with chronic obstructive pulmonary disease.

Material and methods

Cross-sectional observational study in which the results of AAT screening until December 2022 were analyzed. The cases studied were divided into three periods: (1) no systematic case detection until 2013; (2) systematic case detection of S and Z alleles for cases with AAT < 90 mg/dL until 2018, and (3) systematic case detection of 14 mutations for cases with AAT < 120 mg/dL since 2018.

Results

A total of 471 cases were studied, of which 306 (65.0%) were carriers of some mutation related to HAD. The number of detected cases of all mutations with their percentage against those studied in each period was respectively: 6 (100%), 48 (88.8%) and 253 (61.5%). If we limit to severe mutations (AAT < 57.2 mg/dL), the distribution by periods was respectively: 3 (50.0), 10 (18.5%) and 17 (4.1%).

Conclusions

The present study describes the changes in the detection of patients carrying DAAT-related alleles with three different case identification policies. The data support the use of systematic case detection system in the COPD patient population.

Distribution of alpha1 antitrypsin rare alleles in six countries: Results from the Progenika diagnostic network

BACKGROUND

Knowledge of the frequency of rare SERPINA1 mutations could help in the management of alpha1 antitrypsin deficiency (AATD). The present study aims to assess the frequencies of rare and null alleles and their respiratory and hepatic pathogenicity.

METHODS

This is a secondary analysis of a study that evaluated the viability of the Progenika diagnostic genotyping system in six different countries by analyzing 30,827 samples from cases of suspected AATD. Allele-specific genotyping was carried out with the Progenika A1AT Genotyping Test which analyses 14 mutations in buccal swabs or dried blood spots samples. SERPINA1 gene sequencing was performed for serum AAT-genotype discrepancies or by request of the clinician. Only cases with rare mutations were included in this analysis.

RESULTS

There were 818 cases (2.6%) carrying a rare allele, excluding newly identified mutations. All were heterozygous except for 20 that were homozygous. The most frequent alleles were the M-like alleles, PI*M_malton and PI*M_heerlen. Of the 14 mutations included in the Progenika panel, there were no cases detected of PI*S_iiyama, PI*Q0_{granite falls} and PI*Q0_west. Other alleles not included in the 14-mutation panel and identified by gene sequencing included PI*M_würzburg, PI*Z_bristol, and PI*Z_wrexham, and the null alleles PI*Q0_porto, PI*Q0_madrid, PI*Q0_brescia, and PI*Q0_kayseri.

CONCLUSIONS

The Progenika diagnostic network has allowed the identification of several rare alleles, some unexpected and not included in the initial diagnostic panel. This establishes a new perspective on the distribution of these alleles in different countries. These findings may help prioritize allele selection for routine testing and highlights the need for further research into their pathogenetic role.

Genetic testing of allelic variants of PIZ (GLU342Lys, RS28929474) and PIS (GLU264Val, RS17580) of SERPINA1 gene in children with bronchial asthma

According to world publications, mutations in the SERPINA1 gene may be a genetic risk factor for severe chronic obstructive pulmonary disease and, consequently, rapid progression of respiratory dysfunction. This disease leads to a decrease in the level of alpha-1-antitrypsin protein. It is inherited by autosomal recessive type, but there are registered cases of codominance. In the absence of treatment, diseases of the respiratory system become chronic and lead to disability in adulthood. Early diagnosis of AAT deficiency is important to prevent complications and reduce mortality among people with this pathology. Due to these factors, genetic testing of SERPINA1 gene mutations in children with chronic lung diseases is appropriate to detect and prevent severe complications, associated with AATD. The aim of this work is to improve the effectiveness of early diagnosis of AAT deficiency in children with bronchial asthma and recurrent obstructive bronchitis by identifying different genotypes and phenotypes of A1AT deficiency, studying their relationship with the clinical course of respiratory diseases in children

Frequency of alleles and genotypes associated with alpha-1 antitrypsin deficiency in clinical and general populations: Revelations about underdiagnosis

BACKGROUND AND OBJECTIVE

Alpha-1 antitrypsin deficiency (AATD) is an underdiagnosed hereditary condition that promotes the development of lung and liver diseases, and the most common potentially life-threatening genetic condition in Caucasian adults. In this study, the clinical and genetic profile of pulmonary patients from a single center in La Palma Island (Canary Islands, Spain) was assessed to predict how to increase AATD diagnosis.

METHODS

AATD was tested in 1,493 pulmonary outpatients without regard to respiratory symptoms and 465 newborns. Variants of the SERPINA1 gene were characterised by real-time PCR, DNA sequencing, molecular haplotyping and phenotyping (AAT isoelectric focusing). Different respiratory pathologies were diagnosed in patients and their levels of serum AAT were measured by nephelometry.

RESULTS

The prevalence of pneumological patients with AATD alleles was 30.5%, including PI*S, PI*Z and 6 rare genetic variants. Certain deficiency genotypes were unevenly distributed among patients diagnosed with respiratory diseases: PI*ZZ (71.4%) and PI*SS (34.8%) genotypes were more represented in patients with chronic obstructive pulmonary disease (COPD), whereas PI*MZ (27.7%) and PI*SZ (34.5%) genotypes were more abundant in patients with bronchial asthma. The estimated frequency of PI*S and PI*Z alleles in the general population was 8.2% and 2.1%, respectively. A very significant enrichment (p< 0.01) of PI*S allele, independent of the PI*Z allele, was detected in the clinical population.

CONCLUSIONS

AATD diagnosis would improve if both the COPD and the asthmatic patients were included to screening programs. The prevalence of PI*ZZ genotype in La Palma (1/2,162) was relatively high within Spain (average 1/3,344).

Opinions and Attitudes of Pulmonologists About Augmentation Therapy in Patients with Alpha-1 Antitrypsin Deficiency. A Survey of the EARCO Group

Background

Augmentation therapy (AT) is the only specific treatment licensed for patients with alpha-1 antitrypsin deficiency (AATD) associated lung disease. Since patients with severe AATD may have a very different prognosis and AT requires intravenous infusions for life, the decision to initiate AT may be challenging.

Methods

This survey was conducted on 63 experts in AATD from 13 European countries about their opinions and attitudes regarding AT. Participants were asked to rank the importance of 11 identified factors related with the prescription of AT. In addition, each participant was asked to respond to the indication of AT for 30 out of 500 hypothetical cases developed with the combinations of the 11 factors. Each case was evaluated by 3 experts to check the concordance.

Results

The variables that scored higher on preferences for initiating AT were AAT genotype (score 8.6 from a Likert scale 0–10 (SD: 1.7)), AATD serum level (8.2 (SD:2.4)) and FEV1 (%) decline (7.9 (SD:2.4)). Among the 500 different cases, there was an agreement in indication of AT among the 3 experts in 291 (58.2%). Regarding the variables associated with AT, it was indicated to 81.9% of Pi*ZZ, 52.4% of Pi*SZ and 9.8% of Pi*MZ (p < 0.0001). For Pi*ZZ patients, multivariate analysis identified younger age, reduced FEV1 (%), higher FEV1 decline and worse emphysema as significantly associated with prescription (AUC = 0.8114); for Pi*SZ variables were younger age, worse FEV1 (%) and worse emphysema (AUC = 0.7414); and for Pi*MZ younger age, worse DLCO (%), higher DLCO decline and dyspnea (AUC = 0.8387).

Conclusion

There is a high variability in the criteria for prescription of AT among European experts. Most cases were recommended AT according to guidelines, but a significant number of patients with genotype Pi*SZ and almost 10% Pi*MZ were recommended to initiate AT despite the lack of evidence of efficacy in these genotypes.

Association between circulating alpha-1 antitrypsin polymers and lung and liver disease

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is considered one of the most common genetic diseases and is characterised by the misfolding and polymerisation of the alpha-1 antitrypsin (AAT) protein within hepatocytes. The relevance of circulating polymers (CP) of AAT in the pathogenesis of lung and liver disease is not completely understood. Therefore, the main objective of our study was to determine whether there is an association between the levels of CP of AAT and the severity of lung and liver disease.

METHOD

This was a cross-sectional study in patients with different phenotypes of AATD and controls. To quantify CP, a sandwich ELISA was performed using the 2C1 monoclonal antibody against AAT polymers. Sociodemographic data, clinical characteristics, and liver and lung parameters were collected.

RESULTS

A cohort of 70 patients was recruited: 32 Pi*ZZ (11 on augmentation therapy); 29 Z-heterozygous; 9 with other genotypes. CP were compared with a control group of 47 individuals (35 Pi*MM and 12 Pi*MS). ZZ patients had the highest concentrations of CP (p < 0.001) followed by Z heterozygous. The control group and patients with Pi*SS and Pi*SI had the lowest CP concentrations. Pi*ZZ also had higher levels of liver stiffness measurements (LSM) than the remaining AATD patients. Among patients with one or two Z alleles, two patients with lung and liver impairment showed the highest concentrations of CP (47.5 µg/mL), followed by those with only liver abnormality (n = 6, CP = 34 µg/mL), only lung (n = 18, CP = 26.5 µg/mL) and no abnormalities (n = 23, CP = 14.3 µg/mL). Differences were highly significant (p = 0.004).

CONCLUSIONS

Non-augmented Pi*ZZ and Z-patients with impaired lung function and increased liver stiffness presented higher levels of CP than other clinical phenotypes. Therefore, CP may help to identify patients more at risk of developing lung and liver disease and may provide some insight into the mechanisms of disease.

miR-320c Regulates SERPINA1 Expression and Is Induced in Patients With Pulmonary Disease

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is a genetic condition resulting in lung and liver disease with a great clinical variability. MicroRNAs have been identified as disease modifiers; therefore miRNA deregulation could play an important role in disease heterogeneity. Members of miR-320 family are involved in regulating of multiple processes including inflammation, and have potential specific binding sites in the 3'UTR region of SERPINA1 gene. In this study we explore the involvement of miR-320c, a member of this family, in this disease.

METHODS

Firstly in vitro studies were carried out to demonstrate regulation of SERPINA1 gene by miR-320. Furthermore, the expression of miR-320c was analyzed in the blood of 98 individuals with different AAT serum levels by using quantitative PCR and expression was correlated to clinical parameters of the patients. Finally, HL60 cells were used to analyze induction of miR-320c in inflammatory conditions.

RESULTS

Overexpression of miR-320 members in human HepG2 cells led to inhibition of SERPINA1 expression. Analysis of miR-320c expression in patient's samples revealed significantly increased expression of miR-320c in individuals with pulmonary disease. Additionally, HL60 cells treated with the pro-inflammatory factor lipopolysaccharide (LPS) showed increase in miR-320c expression, suggesting that miR-320c responds to inflammation.

CONCLUSION

Our findings demonstrate that miR-320c inhibits SERPINA1 expression in a hepatic cell line and its levels in blood are associated with lung disease in a cohort of patients with different AAT serum levels. These results suggest that miR-320c can play a role in AAT regulation and could be a biomarker of inflammatory processes in pulmonary diseases.

Update on and future perspectives for the diagnosis of alpha-1 antitrypsin deficiency in Brazil

Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disorder caused by a mutation in the SERPINA1 gene, which encodes the protease inhibitor alpha-1 antitrypsin (AAT). Severe AATD predisposes individuals to COPD and liver disease. Early diagnosis is essential for implementing preventive measures and limiting the disease burden. Although national and international guidelines for the diagnosis and management of AATD have been available for 20 years, more than 85% of cases go undiagnosed and therefore untreated. In Brazil, reasons for the underdiagnosis of AATD include a lack of awareness of the condition among physicians, a racially diverse population, serum AAT levels being assessed in a limited number of individuals, and lack of convenient diagnostic tools. The diagnosis of AATD is based on laboratory test results. The standard diagnostic approach involves the assessment of serum AAT levels, followed by phenotyping, genotyping, gene sequencing, or combinations of those, to detect the specific mutation. Over the past 10 years, new techniques have been developed, offering a rapid, minimally invasive, reliable alternative to traditional testing methods. One such test available in Brazil is the A1AT Genotyping Test, which simultaneously analyzes the 14 most prevalent AATD mutations, using DNA extracted from a buccal swab or dried blood spot. Such advances may contribute to overcoming the problem of underdiagnosis in Brazil and elsewhere, as well as being likely to increase the rate detection of AATD and therefore mitigate the harmful effects of delayed diagnosis.

Alpha-1 antitrypsin (AAT) augmentation therapy in individuals with the PI*MZ genotype: a pro/con debate on a working hypothesis

Alpha-1 antitrypsin deficiency (AATD) is a significantly under-diagnosed genetic condition caused by reduced levels and/or functionality of alpha-1 antitrypsin (AAT), predisposing individuals to lung, liver or other systemic diseases. The management of individuals with the PI*MZ genotype, characterized by mild or moderate AAT deficiency, is less clear than of those with the most common severe deficiency genotype (PI*ZZ). Recent genetic data suggest that the PI*MZ genotype may be significantly more prevalent than currently thought. The only specific treatment for lung disease associated with severe AATD is the intravenous infusion of AAT augmentation therapy, which has been shown to slow disease progression in PI*ZZ individuals. There is no specific evidence for the clinical benefit of AAT therapy in PI*MZ individuals, and the risk of emphysema development in this group remains controversial. As such, current guidelines do not support the use of AAT augmentation in PI*MZ individuals. Here, we discuss the limited data on the PI*MZ genotype and offer pro and con perspectives on pursuing an AAT-specific therapeutic strategy in PI*MZ individuals with lung disease. Ultimately, further research to demonstrate the safety, risk/benefit balance and efficacy of AAT therapy in PI*MZ individuals is needed.

Obstacles to Early Diagnosis and Treatment of Alpha-1 Antitrypsin Deficiency: Current Perspectives

This review summarizes the current research and outlooks regarding the obstacles to diagnosing and treating early alpha-1-antitrypsin deficiency (AATD). It draws on prior systematic reviews and expert surveys to discover precisely what difficulties exist in early diagnosis and treatment of AATD and elucidate potential solutions to ease these difficulties. The perceived rarity of AATD may translate to a condition poorly understood by primary care physicians, and even many respiratory physicians, which results in opportunities for diagnosis being missed, especially in mild or asymptomatic patients. There are diagnostic techniques involving biomarkers and home testing methods which could improve the rate of early diagnosis. With respect to treatment, AATD involves treating two separate pathologies, lung disease and liver disease. The only specific AATD treatment, augmentation therapy, has proven ability in treating lung disease but not liver disease. Alpha-1-antitrypsin (AAT) synthesized in the liver can form damaging polymers that also result in reduced circulating AAT levels and, whilst liver transplantation is used to effectively treat AATD, it is inappropriate in early disease. Novel therapeutic areas such as gene editing and increasing autophagy are therefore being researched as future treatments. Ultimately, diagnosis and treatment are intrinsically linked in AATD, with earlier diagnosis leading to better treatment options and thus better patient outcomes.

Trends in Diagnosis of Alpha-1 Antitrypsin Deficiency Between 2015 and 2019 in a Reference Laboratory

Background

Alpha-1 antitrypsin deficiency (AATD) remains largely underdiagnosed despite recommendations of healthcare institutions and programmes designed to increase awareness. The objective was to analyse the trends in AATD diagnosis during the last 5 years in a Spanish AATD reference laboratory.

Methods

This was a retrospective revision of all alpha-1 antitrypsin (AAT) determinations undertaken in our laboratory from 2015 to 2019. We analysed the number of AAT determinations performed and described the characteristics of the individuals tested, as well as the medical specialties and the reasons for requesting AAT determination.

Results

A total of 3507 determinations were performed, of which 5.5% corresponded to children. A significant increase in the number of AAT determinations was observed from 349 in 2015 to 872 in 2019. Among the samples, 57.6% carried an intermediate AATD (50-119 mg/dL) and 2.4% severe deficiency (<50 mg/dL). The most frequent phenotype in severe AATD individuals was PI*ZZ (78.5%), and aminotransferase levels were above normal in around 43% of children and 30% of adults. Respiratory specialists requested the highest number of AAT determinations (31.5%) followed by digestive diseases and internal medicine (27.5%) and primary care physicians (19.7%). The main reason for AAT determination in severe AATD adults was chronic obstructive pulmonary disease (41.7%), but reasons for requesting AAT determination were not reported in up to 41.7% of adults and 58.3% of children.

Conclusion

There is an increase in the frequency of AATD testing despite the rate of AAT determination remaining low. Awareness about AAT is probably increasing, but the reason for testing is not always clear.

Results of a Diagnostic Procedure Based on Multiplex Technology on Dried Blood Spots and Buccal Swabs for Subjects With Suspected Alpha1 Antitrypsin Deficiency

INTRODUCTION

The objective of this analysis was the evaluation of a new national circuit used for diagnosing alpha1 antitrypsin deficiency (AATD) based on multiplex technology using online registration and mail posted samples from dried blood spots (DBS) and buccal swabs.

METHODS

This is an observational, ongoing study conducted in Spain since March 2018. Samples are coded on a web platform and sent by postal mail to the central laboratory. Allele-specific genotyping for the 14 most common mutations was done with the Luminex 200 Instrument System. Gene sequencing was done if none of the mutations were found and the AAT serum level was <60mg/dl, or by request from the clinician in charge.

RESULTS

At the time of the present report, 5803 (92.9%) samples were processed, 4984 (85.9%) from buccal swab and 819 (14.1%) from DBS. The prevalence of the frequent allele combinations were: MS 19.0%, MZ 14.4%, SS 2.9%, SZ 3.7%, and ZZ: 1.4%. Globally, Z carriers represented 20.0% and S carriers 26.6% of this population, with differences seen between regions. 209 (3.6%) were identified carrying rare alleles, 12 (0.2%) carrying null alleles and 14 (0.3%) new mutations were described. Respiratory diseases other than COPD, including poorly controlled asthma or bronchiectasis, also presented AATD mutations.

CONCLUSIONS

The availability of a diagnostic system based on the simultaneous testing of 14 genetic variants from buccal swabs or DBS sent by postal mail and with web registration has proven to be useful, and the system can improve the timely diagnosis of AATD.

Clinical considerations in individuals with α1-antitrypsin PI*SZ genotype

α₁-Antitrypsin deficiency (AATD), characterised by reduced levels or functionality of α₁-antitrypsin (AAT), is a significantly underdiagnosed genetic condition that predisposes individuals to lung and liver disease. Most of the available data on AATD are based on the most common, severe deficiency genotype (PI*ZZ); therefore, treatment and monitoring requirements for individuals with the PI*SZ genotype, which is associated with a less severe AATD, are not as clear. Recent genetic data suggest the PI*SZ genotype may be significantly more prevalent than currently thought, due in part to less frequent identification in the clinic and less frequent reporting in registries. Intravenous AAT therapy, the only specific treatment for patients with AATD, has been shown to slow disease progression in PI*ZZ individuals; however, there is no specific evidence for AAT therapy in PI*SZ individuals, and it remains unclear whether AAT therapy should be considered in these patients. This narrative review evaluates the available data on the PI*SZ genotype, including genetic prevalence, the age of diagnosis and development of respiratory symptoms compared with PI*ZZ individuals, and the impact of factors such as index versus non-index identification and smoking history. In addition, the relevance of the putative 11 µM “protective threshold” for AAT therapy and the risk of liver disease in PI*SZ individuals is explored. The purpose of this review is to identify open research questions in this area, with the aim of optimising the future identification and management of PI*SZ individuals.

Individuals with α₁-antitrypsin (AAT) PI*SZ genotype appear to have an increased risk for lung and liver disease, although definitive evidence is lacking; smoking is a major risk factor for lung disease. The role of AAT therapy requires further study.http://bit.ly/2TxxFD0

miR-320c Regulates SERPINA1 Expression and Is Induced in Patients With Pulmonary Disease

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is a genetic condition resulting in lung and liver disease with a great clinical variability. MicroRNAs have been identified as disease modifiers; therefore miRNA deregulation could play an important role in disease heterogeneity. Members of miR-320 family are involved in regulating of multiple processes including inflammation, and have potential specific binding sites in the 3'UTR region of SERPINA1 gene. In this study we explore the involvement of miR-320c, a member of this family, in this disease.

METHODS

Firstly in vitro studies were carried out to demonstrate regulation of SERPINA1 gene by miR-320. Furthermore, the expression of miR-320c was analyzed in the blood of 98 individuals with different AAT serum levels by using quantitative PCR and expression was correlated to clinical parameters of the patients. Finally, HL60 cells were used to analyze induction of miR-320c in inflammatory conditions.

RESULTS

Overexpression of miR-320 members in human HepG2 cells led to inhibition of SERPINA1 expression. Analysis of miR-320c expression in patient's samples revealed significantly increased expression of miR-320c in individuals with pulmonary disease. Additionally, HL60 cells treated with the pro-inflammatory factor lipopolysaccharide (LPS) showed increase in miR-320c expression, suggesting that miR-320c responds to inflammation.

CONCLUSION

Our findings demonstrate that miR-320c inhibits SERPINA1 expression in a hepatic cell line and its levels in blood are associated with lung disease in a cohort of patients with different AAT serum levels. These results suggest that miR-320c can play a role in AAT regulation and could be a biomarker of inflammatory processes in pulmonary diseases.

Knowledge of Rare Respiratory Diseases among Paediatricians and Medical School Students

Alpha-1-antitrypsin deficiency (AATD) and primary ciliary dyskinesia (PCD) are underdiagnosed rare diseases showing a median diagnostic delay of five to ten years, which has negative effects on patient prognosis. Lack of awareness and education among healthcare professionals involved in the management of these patients have been suggested as possible causes. Our aim was to assess knowledge of these diseases among paediatricians and medical school students to determine which knowledge areas are most deficient. A survey was designed with questions testing fundamental aspects of the diagnosis and treatment of AATD and PCD. A score equal to or greater than 50% of the maximum score was set as the level necessary to ensure a good knowledge of both diseases. Our results indicate a profound lack of knowledge of rare respiratory diseases among paediatric professionals and medical students, suggesting that it is necessary to increase rare respiratory diseases training among all physicians responsible for suspecting and diagnosing them; this will allow early diagnosis and the setup of preventive measures and appropriate early-stage treatment. The first step in closing this knowledge gap could be to include relevant material in the medical syllabus.

Prevalence of Alpha-1 Antitrypsin Deficiency in COPD Patients in Argentina. The DAAT.AR Study

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is still underdiagnosed, despite the recommendation to determine AAT in patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVE

To estimate the prevalence of AATD in COPD patients adjusted according to the population of the COPD prevalence study in Argentina (EPOC.AR).

MATERIAL AND METHODS

This was a multicenter prospective cross-sectional study of a population aged≥30 years of age diagnosed with COPD, involving AAT quantification in dry blood spot and subsequent genotyping in subjects with<1.5mg/dL AAT in dry blood spot (<80mg/dL in serum). AAT was defined as the detection of variants ZZ or SZ on genotyping. The EPOC.AR study population was used to calculate local adjusted prevalence.

RESULTS

We included 3,254 patients (544 with AAT<80mg/dL) with a spirometric diagnosis of COPD. The prevalence of AATD in the total study population was 1.29% (95% CI 0.93-1.74), of which 0.92% (95% CI 0.62-1.31) were Pi*ZZ and 0.37% (95% CI 0.19-0.64) Pi*SZ. The adjusted prevalence of AATD in COPD patients≥40 years of age was 0.83% (95% CI 0.23-2.08). We found that AATD was negatively associated with age (OR 0.94; 95% CI 0.90-0.98; P=.006), smoking habit (OR 0.98; 95% CI 0.96-0.99; P=.009), and FEV₁% (OR 0.95; 95% CI 0.91-0.99; P=.015).

CONCLUSIONS

The prevalence of AATD in the adult population with COPD in Argentina is estimated to be 0.83%, which could represent 17,000 cases in our country.

An analysis of the degree of concordance among international guidelines regarding alpha-1 antitrypsin deficiency

Background

Practice guidelines (PGs) attempt to standardize practice to optimize care. For uncommon lung diseases like alpha-1 antitrypsin deficiency (AATD), a paucity of definitive studies and geographic variation in prevalence may hamper guideline generation. The current study assembled and assesses the degree of concordance among available PGs regarding AATD.

Methods

To assess concordance, 15 eligible guidelines focused on AATD were evaluated regarding recommendations surrounding 24 key clinical issues. A Delphi process achieved consensus on ratings for each statement among 3 reviewers. Agreement was quantified as the proportion of guideline comparisons with a matching rating.

Results

The overall level of agreement was 47% (1190/2520 comparisons). The overall “affirmative agreement percentage” (ie, when guidelines agreed in endorsing a practice), was 42% (501/1190 comparisons). The agreement for individual clinical statements ranged from 26% to 75%. A broad consensus was seen in the recommendation to test all patients with a history of fixed obstruction on pulmonary function testing (either from asthma or COPD). Given that AATD is an under-recognized disease and that diagnosis often occurs at a late stage, the authors are encouraged by this consensus. Where overall the guidelines were less explicit was when to refer to a specialist or AATD center. Deciding on a treatment strategy requires a thorough understanding of the alpha 1 serum level, genotype, pulmonary function testing, and imaging, and therefore the authors feel that all patients would benefit from a specialty referral if the diagnosis of AATD is being considered.

Conclusion

Available guidelines regarding AATD frequently disagreed in management recommendations. Possible explanations for discordance include differences in regional prevalence, availability of augmentation therapy, and insurance environments. Attempts to harmonize the various guidelines by empaneling a broadly representative international group of disease experts should be considered for AATD. Similar comparisons among guidelines for other diseases are recommended.

Portuguese consensus document for the management of alpha-1-antitrypsin deficiency

Alpha-1-antitrypsin deficiency (AATD) is a genetic autosomal codominant disorder caused by mutations in SERPINA1 gene. It is one of the most prevalent genetic disorders, although it remains underdiagnosed. Whereas at international level there are several areas of consensus on this disorder, in Portugal, inter-hospital heterogeneity in clinical practice and resources available have been adding difficulties in reaching a diagnosis and in making therapeutic decisions in this group of patients. This raised a need to draft a document expressing a national consensus for AATD. To this end, a group of experts in this field was created within the Portuguese Pulmonology Society - Study group on AATD, in order to elaborate the current manuscript. The authors reviewed the existing literature and provide here general guidance and extensive recommendations for the diagnosis and management of AATD that can be adopted by Portuguese clinicians from different areas of Medicine. This article is part of a supplement entitled "Portuguese consensus document for the management of alpha-1-antitrypsin deficiency" which is sponsored by Sociedade Portuguesa de Pneumologia.

Diagnosis and management of α1-antitrypsin deficiency in Europe: an expert survey

Despite recent improvements, α1-antitrypsin deficiency (AATD) remains a rarely diagnosed and treated condition. To assess the variability of AATD diagnosis/treatment in Europe, and to evaluate clinicians' views on methods to optimise management, specialist AATD clinicians were invited to complete a web-based survey. Surveys were completed by 15 physicians from 14 centres in 13 European countries. All respondents perceived the AATD diagnosis rate to be low in their country; 77% of physicians believed that ∼15% of cases were diagnosed. Low awareness was perceived as the greatest barrier to diagnosis. Spirometry was considered more practical than quantitative computed tomography (QCT) for monitoring AATD patients in clinical practice; QCT was considered more useful in trials. AAT therapy provision was reported to be highly variable: France and Germany were reported to treat the highest proportion (∼60%) of diagnosed patients, in contrast to the UK and Hungary, where virtually no patients receive AAT therapy. Most clinicians supported self-administration and extended dosing intervals to improve convenience of AAT therapy. This survey indicates that AATD diagnosis and management are highly heterogeneous in Europe; European cooperation is essential to generate data to support access to AAT therapy. Improving convenience of AAT therapy is an ongoing objective.

Alpha 1-antitrypsin deficiency in patients with chronic obstructive pulmonary disease patients: is systematic screening necessary?

OBJECTIVE

Alpha-1-antitrypsin deficiency is a relatively prevalent, but under-diagnosed, genetic disease. The objective of this study was to assess whether the systematic screening for alpha-1-antitrypsin deficiency in all patients with chronic obstructive pulmonary disease from a tertiary service has an impact on the number of patients being diagnosed with this condition.

RESULTS

Chronic obstructive pulmonary disease patients were screened for alpha-1-antitrypsin deficiency using immunonephelometry. The presence of a mutation was confirmed by molecular study of the SERPINA1 gene or by genetic sequencing, as needed. A total of 551 patients with chronic obstructive pulmonary disease were analyzed. Among these, 40 (7.2%) had some genetic mutation, while 11 (2%) had a Pi*ZZ genotype, resulting in severe respiratory illness. The systematic evaluation of chronic obstructive pulmonary disease patients revealed that screening is an effective method to diagnose alpha-1-antitrypsin deficiency. Early diagnosis may facilitate smoking cessation and initiation of treatment to maintain lung function.

Diagnosis and treatment of pulmonarydisease in α1-antitrypsin deficiency: a statement of European Respiratory Society

Alfa-1-antitrypsin deficiency (AATD) is the most common hereditary disorder in adults. It is associated with an increased risk of developing pulmonary emphysema and liver disease. The lung injury in AATD is closely associated with smoking, but progressive lung disease could occur even in never-smokers. A number of individuals with AATD remain undiagnosed and therefore do not receive appropriate care and treatment. The most recent international document on AATD was the joint statement of the American Thoracic Society and the European Respiratory Society published in 2003. Thereafter, there has been a continuous development of novel, more accurate and less expensive genetic diagnostic methods. Furthermore, new outcome parameters have been developed and validated for use in clinical trials and a new series of observational and randomized clinical trials have provided more evidence concerning the efficacy and safety of augmentation therapy, the only specific treatment available for the pulmonary disease associated with AATD. As AATD is a rare disease, it is important to createnational and international registries and to collect information prospectively about the natural history of the disease. Management of AATD patients must be supervised by national or regional expert centres and inequalities in access to therapies across Europe should be addressed.

Alpha-1 antitrypsin deficiency: outstanding questions and future directions

Background

Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition that leads to decreased circulating alpha-1 antitrypsin (AAT) levels, significantly increasing the risk of serious lung and/or liver disease in children and adults, in which some aspects remain unresolved.

Methods

In this review, we summarise and update current knowledge on alpha-1 antitrypsin deficiency in order to identify and discuss areas of controversy and formulate questions that need further research.

Results

1) AATD is a highly underdiagnosed condition. Over 120,000 European individuals are estimated to have severe AATD and more than 90% of them are underdiagnosed.

Conclusions

2) Several clinical and etiological aspects of the disease are yet to be resolved. New strategies for early detection and biomarkers for patient outcome prediction are needed to reduce morbidity and mortality in these patients; 3) Augmentation therapy is the only specific approved therapy that has shown clinical efficacy in delaying the progression of emphysema. Regrettably, some countries reject registration and reimbursement for this treatment because of the lack of larger randomised, placebo-controlled trials. 4) Alternative strategies are currently being investigated, including the use of gene therapy or induced pluripotent stem cells, and non-augmentation strategies to prevent AAT polymerisation inside hepatocytes.

Diagnosis of alpha1-antitrypsin deficiency not just in severe COPD

Alpha1-antitrypsin deficiency (AATD) is a well known genetic risk factor for pulmonary disease and is the most frequent hereditary disease diagnosed in adults. Despite being one of the most common hereditary diseases, AATD remains under-diagnosed because of its variable clinical presentation and the poor knowledge of this disease by physicians. With the aim of identifying clinical differences that could influence early diagnosis, we compared two groups of six AATD Pi*ZZ patients with different lung function severity and clinical expression at diagnosis. On comparing the two groups, we observed a younger mean age at diagnosis and more exacerbations in the severe group, but the percentage of smokers did not statistically differ between the two groups. Our results suggest that AATD continues being a disease suspected on younger patients with a worse lung function. In addition these findings confirm the clinical variability of the disease and that there are still unknown factors that contribute to its development. Therefore, early diagnosis may modify the prognosis of this disease.

Epidemiology of Rare Lung Diseases: The Challenges and Opportunities to Improve Research and Knowledge

Rare lung diseases encompass a broad spectrum of conditions and affect an estimated 1.2-2.5 million people in North America and 1.5-3 million people in Europe. While individual rare lung diseases affect less than 1 in 2000 individuals, collectively they have a significant impact upon the population at large. Hence it is vital to understand firstly the epidemiology and subsequently the pathogenesis and clinical course of these disorders. Through a greater understanding of these aspects of disease, progress can be made in reducing symptoms, containing healthcare costs and utilizing resources efficiently. Furthermore, a greater understanding of the pathobiology of rare lung diseases can inform both the pathogenesis and management of more common pulmonary disorders.In this chapter we review how epidemiological approaches and the utilization of patient registries has improved the knowledge and management of rare lung diseases. We further focus on the epidemiology of several of the more widely known rare pulmonary disorders, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF) and alpha-1 antitrypsin deficiency (AATD). To conclude we describe how patient advocacy groups and foundations have driven advances in research and management of ultra-rare lung diseases, namely, the major strides made in the management and understanding of lymphangioleiomyomatosis (LAM) and pulmonary alveolar proteinosis (PAP).We conclude that the models used to study some of the rarest of diseases may be successfully adopted by other rare and common disease communities, leading to improved care and the possibility of novel therapeutic options.

Characterization of Novel Missense Variants of SERPINA1 Gene Causing Alpha-1 Antitrypsin Deficiency

The SERPINA1 gene is highly polymorphic, with more than 100 variants described in databases. SERPINA1 encodes the alpha-1 antitrypsin (AAT) protein, and severe deficiency of AAT is a major contributor to pulmonary emphysema and liver diseases. In Spanish patients with AAT deficiency, we identified seven new variants of the SERPINA1 gene involving amino acid substitutions in different exons: PiSDonosti (S+Ser14Phe), PiTijarafe (Ile50Asn), PiSevilla (Ala58Asp), PiCadiz (Glu151Lys), PiTarragona (Phe227Cys), PiPuerto Real (Thr249Ala), and PiValencia (Lys328Glu). We examined the characteristics of these variants and the putative association with the disease. Mutant proteins were overexpressed in HEK293T cells, and AAT expression, polymerization, degradation, and secretion, as well as antielastase activity, were analyzed by periodic acid-Schiff staining, Western blotting, pulse-chase, and elastase inhibition assays. When overexpressed, S+S14F, I50N, A58D, F227C, and T249A variants formed intracellular polymers and did not secrete AAT protein. Both the E151K and K328E variants secreted AAT protein and did not form polymers, although K328E showed intracellular retention and reduced antielastase activity. We conclude that deficient variants may be more frequent than previously thought and that their discovery is possible only by the complete sequencing of the gene and subsequent functional characterization. Better knowledge of SERPINA1 variants would improve diagnosis and management of individuals with AAT deficiency.

Long-term evolution of lung function in individuals with alpha-1 antitrypsin deficiency from the Spanish registry (REDAAT)

Background

The clinical course of alpha-1 antitrypsin deficiency (AATD) is very heterogeneous. It is estimated that 60% of individuals with severe AATD (Pi*ZZ) develop emphysema. The main objective of this study was to describe the outcomes of long-term lung function in individuals with AATD-associated emphysema after at least 8 years of follow-up.

Materials and methods

We performed a retrospective analysis of longitudinal follow-up data of AATD PiZZ patients from the Spanish registry (AATD Spanish Registry [REDAAT]). The main follow-up outcome was the annual rate of decline in forced expiratory volume in 1 second (FEV₁) calculated using the FEV₁ values at baseline and in the last post-bronchodilator spirometry available.

Results

One hundred and twenty-two AATD PiZZ patients were analyzed. The median follow-up was 11 years (interquartile range =9–14). The mean FEV₁ decline was 28 mL/year (SD=54), with a median of 33 mL/year. Tobacco consumption (β=19.8, p<0.001), previous pneumonia (β=27.8, p=0.026) and higher baseline FEV₁% (β=0.798, p=0.016) were independently related to a faster FEV₁ decline.

Conclusion

In this large cohort with a long follow-up, we observed a very variable decline of FEV₁. However, the mean FEV₁ decline was similar to that observed in large cohorts of smoking-related COPD. Tobacco consumption, previous pneumonia and better lung function at baseline were related to a faster decline in FEV₁. These results highlight the importance of early diagnosis and effective treatment.

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

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

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

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

Alpha 1-antitrypsin ameliorates ventilator-induced lung injury in rats by inhibiting inflammatory responses and apoptosis

Mechanical ventilation is extensively used to treat patients with lung injury but may result in ventilator-induced lung injury (VILI). The present study investigated the protective effect of alpha 1-antitrypsin (AAT) on VILI. Adult male rats were subjected to sham, ventilation + saline, or ventilation + AAT treatment and lung injuries were evaluated. Peripheral blood and bronchoalveolar lavage fluid (BALF) were obtained to assess systemic and local inflammatory responses, respectively. Mechanical ventilation resulted in lung injury, as evidenced by histological abnormalities as well as elevations in PaO₂/FiO₂ ratio, the wet-to-dry weight ratio, and the BALF level of proteins. The intravenous administration of AAT significantly improved these parameters of lung function, suggesting a protective role of AAT in VILI. Mechanistically, ventilator-induced inflammation was effectively reduced by AAT, as evidenced by decreases in BALF neutrophil counts, BALF cytokines, and serum adhesion factors. In contrast, anti-inflammatory interleukin-10 in BALF was increased in response to AAT. AAT treatment also inhibited the expression of nuclear factor-κB, Bax, and cleaved caspase-3 while promoting Bcl-2 expression in ventilator-injured lung tissues. AAT treatment can ameliorate VILI by inhibiting inflammatory mediator production and apoptosis. Impact statement Mechanical ventilation has been commonly used to treat patients with lung injury but may result in ventilator-induced lung injury (VILI). Few effective treatment options are currently available to reduce VILI. Alpha 1-antitrypsin (AAT) is an inhibitor of serine protease with anti-inflammatory and antiapoptotic properties, suggesting a possible role in attenuating lung injury. The present study demonstrates that AAT inhibits the development of VILI by modulating inflammation- and apoptosis-related protein expression. Therefore, AAT may be a novel therapeutic agent for acute respiratory distress syndrome patients undergoing mechanical ventilation.

Clinical utility of alpha-1 proteinase inhibitor in the management of adult patients with severe alpha-1 antitrypsin deficiency: a review of the current literature

Alpha-1 antitrypsin (AAT) functions primarily to inhibit neutrophil elastase, and its deficiency predisposes individuals to the development of chronic obstructive pulmonary disease (COPD). The putative protective serum concentration is generally considered to be above a threshold of 11 μM/L, and therapeutic augmentation of AAT above this value is believed to retard the progression of emphysema. Several AAT preparations, all derived from human donor plasma, have been commercialized since approval by the US Food and Drug Administration (FDA) in 1987. Biochemical efficacy has been demonstrated by augmentation of pulmonary antiprotease activity, but demonstration of clinical efficacy in randomized, placebo-controlled trials has been hampered by the practical difficulties of performing conventional studies in a rare disease with a relatively long natural history. Computed tomography has been applied to measure lung density as a more specific and sensitive surrogate outcome measure of emphysema than physiologic indices, such as forced expiratory volume in 1 second, and studies consistently show a therapeutic reduction in the rate of lung density decline. However, convincing evidence of benefit using traditional clinical measures remains elusive. Intravenous administration of AAT at a dose of 60 mg/kg/week is the commonest regime in use and has well-documented safety and tolerability. International and national guidelines on the management of AAT deficiency recommend intravenous augmentation therapy to supplement optimized usual COPD treatment in patients with severe deficiency and evidence of lung function impairment.

Spanish Guidelines for Management of Chronic Obstructive Pulmonary Disease (GesEPOC) 2017. Pharmacological Treatment of Stable Phase

The clinical presentation of chronic obstructive pulmonary disease (COPD) varies widely, so treatment must be tailored according to the level of risk and phenotype. In 2012, the Spanish COPD Guidelines (GesEPOC) first established pharmacological treatment regimens based on clinical phenotypes. These regimens were subsequently adopted by other national guidelines, and since then, have been backed up by new evidence. In this 2017 update, the original severity classification has been replaced by a much simpler risk classification (low or high risk), on the basis of lung function, dyspnea grade, and history of exacerbations, while determination of clinical phenotype is recommended only in high-risk patients. The same clinical phenotypes have been maintained: non-exacerbator, asthma-COPD overlap (ACO), exacerbator with emphysema, and exacerbator with bronchitis. Pharmacological treatment of COPD is based on bronchodilators, the only treatment recommended in low-risk patients. High-risk patients will receive different drugs in addition to bronchodilators, depending on their clinical phenotype. GesEPOC reflects a more individualized approach to COPD treatment, according to patient clinical characteristics and level of risk or complexity.

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.