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

Early Origins of Chronic Obstructive Pulmonary Disease: Prenatal and Early Life Risk Factors

The main risk factor for chronic obstructive pulmonary disease (COPD) is active smoking. However, a considerable amount of people with COPD never smoked, and increasing evidence suggests that adult lung disease can have its origins in prenatal and early life. This article reviews some of the factors that can potentially affect lung development and lung function trajectories throughout the lifespan from genetics and prematurity to respiratory tract infections and childhood asthma. Maternal smoking and air pollution exposure were also analyzed among the environmental factors. The adoption of preventive strategies to avoid these risk factors since the prenatal period may be crucial to prevent, delay the onset or modify the progression of COPD lung disease throughout life.

Feasibility of a genotyping system for the diagnosis of alpha1 antitrypsin deficiency: a multinational cross-sectional analysis

Introduction

Currently, strategies for improving alpha1 antitrypsin deficiency (AATD) diagnosis are needed. Here we report the performance of a multinational multiplex-based genotyping test on dried blood spots and buccal swabs sent by post or courier and with web registration for subjects with suspected AATD in Argentina, Brazil, Chile, Colombia, Spain, and Turkey.

Methods

This was an observational, cross-sectional analysis of samples from patients with suspected AATD from March 2018 to January 2022. Samples were coded on a web platform and sent by post or courier to the central laboratory in Northern Spain. Allele-specific genotyping for the 14 most common mutations was carried out with the A1AT Genotyping Test (Progenika-Grifols, Spain). SERPINA1 gene sequencing was performed if none of the mutations were found or one variant was detected in heterozygous status and the AAT serum level was < 60 mg/dl, or if requested by the clinician in charge.

Results

The study included 30,827 samples: 30,458 (94.7%) with final results after direct genotyping and 369 (1.1%) with additional gene sequencing. Only 0.3% of the samples were not processed due to their poor quality. The prevalence of the most frequent allele combinations was MS 14.7%, MZ 8.6%, SS 1.9%, SZ 1.9%, and ZZ 0.9%. Additionally, 70 cases with new mutations were identified. Family screening was conducted in 2.5% of the samples. Samples from patients with respiratory diseases other than COPD, including poorly controlled asthma or bronchiectasis, also presented AATD mutations.

Conclusions

Our results confirm the viability of this diagnostic system for genotyping AATD conducted simultaneously in different countries. The system has proved satisfactory and can improve the timely diagnosis of AATD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02074-x.

Developing lung cancer in COPD: Possible role of carrying Alpha-1 antitrypsin deficiency variants

Introduction

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation and airway inflammation, with a prevalence of 10.1%. Among the many causes of COPD, Smoking is the leading and another big cause is (AATD α1-antitrypsin deficiency)’ an inherited disorder. Prevalence of COPD patients is 1.9%. World Health Organization (WHO) advice all COPD patients’ AATD rate to be screened at least once during their life.

The prevalence of AATD in the general population ranges from 1:2,000–5,000 in parts of Europe and from 1 to 5,000–10,000 in the United States and Canada.

Case 1

An 81-year-old male patient with COPD. In computed tomography (CT) of the thorax, mass in the right lower lobe and a nodule in the right upper lobe were detected. The biopsy from right bronchial entrance via fiberoptic bronchoscopy (FB) yielded squamous cell carcinoma (SCC). AAT level was 169 mg/dL (ref. range: 90–200 mg/dL). M/P lowell allele was detected in genetic analysis.

Case 2

A 45-year-old male patient with COPD. Conglomerated lymhadenomegaly in the paratracheal area was detected in CT. The biopsy from mucosal infiltrates initiating from the entrance of the right upper lobe to the anterior segment revealed SCC. His AAT level was 190 mg/dL (ref. range: 90–200 mg/dL) and the genetic analysis demonstrated M/I mutation.

Case 3

A 64-year-old male COPD patient. In thorax CT, a 24 mm diameter parenchymal nodule in the left lower lobe was detected. Transthoracic fine needle aspiration biopsy from the left lung nodule showed SCC. His AAT level was 196 mg/dL (ref. range: 90–200 mg/dL) and M/P lowell allele was detected in the genetic analysis.

Discussion

AAT deficiency can cause early-onset of COPD, manifested with emphysema and chronic bronchitis. It has been suggested that AATD is associated with an increased risk of many types of cancer. Although the relationship between AATD or variant carriage and LC histopathology is not clear in the literature, it was detected as squamous cell carcinoma in our cases. We infer that unmeasurable lung damage is more prevalent in heterozygous patients and we believe that sharing our results may draw more attention in this regard.

Variability of blood eosinophil count and prognosis of COPD exacerbations

BACKGROUND

Eosinophils in peripheral blood are one of the emerging biomarkers in chronic obstructive pulmonary disease (COPD) patients. However, when analysing the relationship between peripheral eosinophilia and COPD prognosis, highly variable results are obtained. The aim of our study is to describe the serum eosinophilia levels in COPD patients and to analyse their relationship to prognosis following hospital admission.

METHODS

A prospective observational study was conducted from 1 October 2016 to 1 October 2018 in the following Spanish centres: Salnés County Hospital in Vilagarcía de Arousa, Arquitecto Marcide Hospital in Ferrol and the University Hospital Complex in Santiago de Compostela. The patients were classified using three cut-off points of blood eosinophil count (BEC): 150 cells/µL, 300 cells/µL, and 400 cells/µL; in addition, the peripheral BEC was analysed on admission.

RESULTS

615 patients were included in the study, 86.2% male, mean age 73.9 years, and mean FEV1 52.7%. The mean stay was 8.4 days, and 6% of all patients were readmitted early. No significant relationship was observed between the BEC, neither in the stable phase nor in the acute phase, and hospital stay, readmissions, deaths during admission, the need for intensive care, or the condition of frequent exacerbator.

CONCLUSION

The results of our study do not seem to support the usefulness of BEC as a COPD biomarker.KEY MESSAGESThere is evidence that BEC participates in pathophysiological mechanisms of the COPD.BEC may be useful as a biomarker in COPD for aspects such as the optimization of treatments.We did not find any relationship between BEC levels and prognosis following hospital admission for AECOPD.

Methodologies for the Determination of Blood Alpha1 Antitrypsin Levels: A Systematic Review

Background: The study of hematic concentrations of alpha1 antitrypsin (AAT) is currently one step in the diagnosis of AAT deficiency. To try to clarify the relevance of the laboratory techniques, we carried out a systematic review of the literature. Methods: Studies evaluating the quantification of AAT in peripheral blood were searched in PubMed in July 2021. The selection criteria included (1) any type of study design that included a quantification of AAT in peripheral blood; (2) studies written in English or Spanish; (3) studies evaluating human beings; and (4) studies involving adults. Results: Out of 207 studies, the most frequently used techniques were nephelometry (43.9%), followed by ELISA (19.8%) and turbidimetry (13.5%). Altogether, 182 (87.9%) cases expressed their results in units of gram, while 16 (7.7%) articles expressed them in units of mole. Only 2.9% articles referred to the standard used, 43.5% articles indicated the commercial kit used, and 36.2% indicated the analyzer used. Conclusions: The technical aspects of these determinations are not always reported in the literature. Journals should be attentive to these technical requirements and ensure that they are included in the works in which AAT is determined in order to ensure a correct interpretation of the study findings.

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 Screening in a Selected Cohort of Patients Affected by Chronic Pulmonary Diseases in Naples, Italy

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is a genetic condition associated with several respiratory diseases in patients with severe protein deficiency. AATD is often late diagnosed or underdiagnosed. Diagnosis frequently occurs in patients with chronic obstructive pulmonary disease and emphysema characterized by frequent exacerbations and over ten years' duration. The purpose of this study was to evaluate the incidence of alpha-1 antitrypsin deficiency in patients with the chronic pulmonary disease after a thorough screening in the city of Naples in southern Italy.

MATERIALS AND METHODS

Two hundred patients suffering from respiratory pathology (chronic obstructive pulmonary disease (COPD), emphysema, asthma, or bronchiectasis) were examined and evaluated in our outpatients' clinic and tested for serum levels of AAT. Patients who had a respiratory disease suspected of AATD and/or serum AAT < 120 mg/dL underwent genetic testing. Genetic screening was performed on samples from 141 patients.

RESULTS

A total of 36 patients had an intermediate deficiency of AAT levels. Among them, 8 were PI*MZ, 6 were PI*MS and 22 had rare pathological mutations. Five patients had a severe AATD, all were composite heterozygous with S or Z allele, while the other allele had a rare pathological mutation.

CONCLUSIONS

The incidence of genetic defects as AATD in the population of patients affected by chronic respiratory disorders is always a matter of discussion because of the frequent interaction between genes and environmental causes. In our series, numerous rare variants and compound heterozygosity have been described. No homozygous patients have been described. The present is one of few studies available on the incidence of rare variants in the geographic area of the city of Naples. So, our results could be considered interesting not only to know the incidence of AATD and its related rare mutations but also to support early diagnosis and treatments for patients with chronic pulmonary disease and frequent exacerbation and to fight the association with environmental causes of pulmonary damages as smoking.

Implications of a Change of Paradigm in Alpha1 Antitrypsin Deficiency Augmentation Therapy: From Biochemical to Clinical Efficacy

Ever since the first studies, restoring proteinase imbalance in the lung has traditionally been considered as the main goal of alpha1 antitrypsin (AAT) replacement therapy. This strategy was therefore based on ensuring biochemical efficacy, identifying a protection threshold, and evaluating different dosage regimens. Subsequently, the publication of the results of the main clinical trials showing a decrease in the progression of pulmonary emphysema has led to a debate over a possible change in the main objective of treatment, from biochemical efficacy to clinical efficacy in terms of lung densitometry deterioration prevention. This new paradigm has produced a series controversies and unanswered questions which face clinicians managing AAT deficiency. In this review, the concepts that led to the approval of AAT replacement therapy are reviewed and discussed under a new prism of achieving clinical efficacy, with the reduction of lung deterioration as the main objective. Here, we propose the use of current knowledge and clinical experience to face existing challenges in different clinical scenarios, in order to help clinicians in decision-making, increase interest in the disease, and stimulate research in this field.