Alpha1-antitrypsin deficiency in Greece: Focus on rare variants.

PURPOSE: A1Antitrypsin deficiency (AATD) pathogenic mutations are expanding beyond the PI*Z and PI*S to a multitude of rare variants. AIM: to investigate genotype and clinical profile of Greeks with AATD. METHODS: Symptomatic adult-patients with early-emphysema defined by fixed airway obstruction and computerized-tomography scan and lower than normal serum AAT levels were enrolled from reference centers all over Greece. Samples were analyzed in the AAT Laboratory, University of Marburg-Germany. RESULTS: Included are 45 adults, 38 homozygous or compound heterozygous for pathogenic variants and 7 heterozygous. Homozygous were 57.9% male, 65.8% ever-smokers, median (IQR) age 49.0(42.5-58.5) years, AAT-levels 0.20(0.08-0.26) g/L, FEV1(%predicted) 41.5(28.8-64.5). PI*Z, PI*Q0, and rare deficient allele's frequency was 51.3%, 32.9%,15.8%, respectively. PI*ZZ genotype was 36.8%, PI*Q0Q0 21.1%, PI*MdeficientMdeficient 7.9%, PI*ZQ0 18.4%, PI*Q0Mdeficient 5.3% and PI*Zrare-deficient 10.5%. Genotyping by Luminex detected: p.(Pro393Leu) associated with MHeerlen (M1Ala/M1Val); p.(Leu65Pro) with MProcida; p.(Lys241Ter) with Q0Bellingham; p.(Leu377Phefs*24) with Q0Mattawa (M1Val) and Q0Ourem (M3); p.(Phe76del) with MMalton (M2), MPalermo (M1Val), MNichinan (V) and Q0LaPalma (S); p.(Asp280Val) with PLowell (M1Val); PDuarte (M4), YBarcelona (p.Pro39His). Gene-sequencing (46.7%) detected Q0GraniteFalls, Q0Saint-Etienne, Q0Amersfoort(M1Ala), MWürzburg, NHartfordcity and one novel-variant (c.1A>G) named Q0Attikon.Heterozygous included PI*MQ0Amersfoort(M1Ala), PI*MMProcida, PI*Mp.(Asp280Val), PI*MOFeyzin. AAT-levels were significantly different between genotypes (p = 0.002). CONCLUSION: Genotyping AATD in Greece, a multiplicity of rare variants and a diversity of rare combinations, including unique ones were observed in two thirds of patients, expanding knowledge regarding European geographical trend in rare variants. Gene sequencing was necessary for genetic diagnosis. In the future the detection of rare genotypes may add to personalize preventive and therapeutic measures.

Alpha-1 antitrypsin deficiency is significantly associated with atopy in asthmatic patients.

Background: Although the etiology and disease mechanisms of asthma and alpha-1 antitrypsin deficiency (AATD) are distinct, several reports indicate that asthma is common in AATD patients, however the relationships between asthma and AATD are poorly described in the literature.Objectives: The aim of the study was to investigate in a cohort of outpatients affected by mild to moderate asthma the clinical features that may differentiate asthmatic patients with and without mutation on SERPINA1 gene.Methods: Seven hundred thirty-five asthmatic outpatients underwent quantitative analysis of the serum level of alpha-1antitrypsin. According to the literature only sixty-seven out of seven hundred thirty-five asthmatic patients were submitted to genetic analysis to identify AATD and non-AATD subjects. Fifty-eight patients were studied. Clinical and functional data, including lung function, atopy and bronchial hyperactivity, were recorded.Results: The fifty-eight asthmatic patients were divided in AATD patients (n = 22) and non AATD patients (n = 36), according to genotype. The presence of atopy was significantly higher in patients with AATD than in those without AATD (91% vs. 64%; p = 0.031). AATD patients reported allergic manifestations more than non AATD patients (77% vs. 47%; p = 0.030).Conclusion: Our study shows that the presence of atopy in asthmatic patients with AATD is significantly higher than in asthmatic patients without gene mutation. In addition, a higher percentage of AATD patients self-reported allergic manifestations. No significant differences in respiratory symptoms, physical examination, disease severity or inflammation markers were found between AATD patients and non AATD patients.

COVID-19 infection in severe Alpha 1-antitrypsin deficiency: Looking for a rationale.

The clinical manifestations of COVID-19 are heterogeneous: 46.4% of patients admitted into hospital reported to have at least one comorbidity. Comorbidities such as COPD, diabetes, hypertension and malignancy predispose patients with Covid-19 to adverse clinical outcomes. Alpha 1-antitrypsin deficiency (AATD) is a genetic disorder caused by pathological mutation(s) in the SERPINA1 gene resulting in an imbalance in proteinase activity which may lead to premature emphysema and COPD. Our aim was to investigate whether people with severe AAT deficiency (AATD) have an increased risk of (severe) COVID-19 infection. We collected data on COVID-19 symptoms, laboratory-confirmed infection, hospitalization and treatment by means of a telephone survey, directly administered to Italian severe AATD subjects in May 2020. We then compared our findings with data collected by the Istituto Superiore di Sanità on the total population in Italy during the same period. We found an higher frequency of SARS-CoV-2 infection in our cohort (3.8%) compared to national data regarding infection, thus giving severe AATD a relative risk of 8. 8 (95%CI 5.1-20,0; p<0.0001) for symptomatic SARS-CoV-2 infection. Moreover, the relative risk (RR) was higher in AATD patients with pre-existing lung diseases (RR 13.9; 95%CI 8.0-33.6; p<0.001), but with a similar death rate (1 in 8, 12.5%) compared to the general population (13.9%; RR 0.9). These preliminary findings highlight the importance of close surveillance in the spread of COVID-19 in patients with severe AATD and underlines the need for further studies into the role of the antiprotease shield in preventing SARS-Cov-2 infection.

Interactions between SERPINA1 PiMZ genotype, occupational exposure and lung function decline.

OBJECTIVES: We evaluated interactions between SERPINA1 PiMZ genotype, associated with intermediate α1-antitrysin deficiency, with outdoor particulate matter ≤10 µm (PM10), and occupational exposure to vapours, dusts, gases and fumes (VGDF), and their effects on annual change in lung function. METHODS: Pre-bronchodilator spirometry was performed in 3739 adults of the Swiss Cohort Study on Air Pollution and Lung Disease in Adults (SAPALDIA) for whom SERPINA1 genotypes were available. At baseline in 1991, participants were aged 18-62 years; follow-up measurements were conducted from 2001 to 2003. In linear mixed regression models of annual change in lung function, multiplicative interactions were evaluated between PiMZ genotype (PiMM as reference) and change in PM10 (µg/m(3)), and VGDF exposure (high-level, low-level or no exposure as reference) during follow-up. RESULTS: Annual declines in forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%) (-82 mL/s, 95% CI -125 to -39) and forced expiratory volume in 1 s over forced vital capacity (FEV1/FVC) (-0.3%, 95% CI -0.6% to 0.0%) in association with VGDF exposure were observed only in PiMZ carriers (Pinteraction<0.0001 and Pinteraction=0.03, respectively). A three-way interaction between PiMZ genotype, smoking and VGDF exposure was identified such that VGDF-associated FEF25-75% decline was observed only in ever smoking PiMZ carriers (Pinteraction=0.01). No interactions were identified between PiMZ genotype and outdoor PM10. CONCLUSIONS: SERPINA1 PiMZ genotype, in combination with smoking, modified the association between occupational VGDF exposure and longitudinal change in lung function, suggesting that interactions between these factors are relevant for lung function decline. These novel findings warrant replication in larger studies.

Laboratory testing of individuals with severe alpha1-antitrypsin deficiency in three European centres.

alpha(1)-Antitrypsin (AT) deficiency is a hereditary disorder that may lead to early-onset emphysema, and chronic liver disease later in life. Although there are validated methods for testing, the vast majority of alpha(1)-AT-deficient individuals remain undiagnosed. Recommendations have been published for the testing and diagnosis of alpha( 1)-AT deficiency; however, guidelines on best practice are not well established. In our article, we review the developments in diagnostic techniques that have taken place in recent years, and describe the practices used in our three European centres. The determination of the level of alpha(1)-AT and genotyping are reported as the main diagnostic steps, whereas isoelectric focusing (also referred to as phenotyping) is reserved for confirmatory analysis. The following recommendations for best practice are put forward: detection of all PiZZ and other severe deficiency individuals; automated genotyping; preparation of reference standards; quality control programmes; development of standard operating procedure documents; and standardised methods for the collection of dried blood samples. Closer cooperation between laboratories and the sharing of knowledge are recommended, with the objectives of improving the efficiency of the diagnosis of severe alpha(1)-AT deficiency, increasing the numbers of individuals who are detected with the disorder, and assisting the establishment of new patient identification programmes.

Secondary outputs of alpha1-antitrypsin deficiency targeted detection programme.

Targeted detection programmes are recommended to identify subjects affected by severe alpha1-antitrypsin deficiency (AATD). Guidelines are available to address physicians towards subjects at high risk for AATD. We wanted to investigate the clinical characteristics of subjects enrolled in the programme, who result as not being affected by severe AATD; this information is not available in the present literature. We elaborated data contained in the questionnaires accompanying the samples of 2127 Italian subjects submitted for AATD detection in a period spanning 11 years (1996-2006). A total of 588 subjects were eligible to enter this study: PI*MM subjects and subjects with intermediate AATD, referred for lung disease, were characterised by a relatively young mean age, and a high proportion (31.2% and 28.6%, respectively) were never smokers. Fifty percent or more had symptoms of chronic bronchitis, but without obstruction. Only a minority belonged to most severe GOLD stages. The mean levels of AAT varied as a function of the presence or absence of airflow obstruction in intermediate AATD subjects, but not in PI*MM. Individuals enrolled in AATD detection programmes represent an interesting cohort both for public health and research purposes.

Alpha-1 antitrypsin deficiency in Italy: regional differences of the PIS and PIZ deficiency alleles.

BACKGROUND: Critical to the effective diagnosis and management of disease is information on its prevalence in a particular geographic area such as Italy. Alpha-1 antitrypsin deficiency (AAT Deficiency) is one of the most common serious hereditary diseases in the world, but its prevalence varies markedly from one country to another. AAT Deficiency affects at least 120.5 million carriers and deficient subjects worldwide for the two most prevalent deficiency alleles PIS and PIZ. This genetic disease is known to exist in Italy and is related to a high risk for development of jaundice in infants, liver disease in children and adults, and pulmonary emphysema in adults. METHODS: Studies on the genetic epidemiology of AAT Deficiency has resulted in the development of a unique database that permits a unique analysis of the geographic distribution in 14 different regions located at random from Piemonte to Sicilia. RESULTS: The use of Hardy-Weinberg statistical analysis to evaluate the distribution of these two deficiency alleles has demonstrated striking differences in the frequencies of these two deficiency alleles in these 14 different regions with 23/84 pair wise combinations significantly different (P=0.05) for PIS, and 5/84 combinations for PIZ. CONCLUSIONS: These findings demonstrate differences that impact the standards of care and diagnosis of AAT Deficiency in Italy since the prevalence of these deficiency alleles is not uniform throughout the country.

Tumour necrosis factor family genes in a phenotype of COPD associated with emphysema.

Genetic factors are believed to play a role in the individual susceptibility to chronic obstructive pulmonary disease (COPD). Tumour necrosis factor (TNF) family genes have been widely investigated but inconsistent results may lie either in the genetic heterogeneity of populations or in the poor phenotype definition. A genetic study was performed using a narrower phenotype of COPD. The authors studied 86 healthy smokers and 63 COPD subjects who were enrolled based on irreversible airflow obstruction (forced expiratory volume in one second/forced vital capacity <70% predicted) and a diffusing capacity for carbon monoxide <50% predicted (moderate-to-severe COPD associated with pulmonary emphysema). The following polymorphisms were investigated: TNF-308, the biallelic polymorphism located in the first intron of the lymphotoxin-alpha gene, and exon 1 and exon 6 of the TNF receptor 1 and 2 genes, respectively. No significant deviations were found concerning the four polymorphisms studied between the two populations. The authors confirm that the tumour necrosis factor family genes, at least for the polymorphisms investigated, are not major genetic risk factors for chronic obstructive pulmonary disease in Caucasians, either defined in terms of emphysema (this study) or airflow obstruction (previous studies). Nevertheless, the authors would like to emphasise the importance of narrowing the phenotype in the search for genetic risk factors in chronic obstructive pulmonary disease.