Das Deutsche Register für Personen mit Alpha-1-Antitrypsin-Mangel – eine Ressource für die Versorgungsforschung

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.

Alpha1-Antitrypsin Deficiency: Transition of Care for the Child With AAT Deficiency into Adulthood

IMPORTANCE

Alpha1-antitrypsin (AAT) deficiency is a common, but an underdiagnosed genetic condition, affecting 1 in 1500 individuals. It can present insidiously with liver disease in children. Although clinical practice guidelines exist for the management of AAT deficiency, especially with regards to pulmonary involvement, there are no published recommendations that specifically relate to the management of the liver disease and monitoring for lung disease associated with this condition, particularly in children.

OBJECTIVE

To review the literature on the management of AAT deficiency-associated liver disease in adults and children.

EVIDENCE REVIEW

A systematic search for articles indexed in PubMed and published was undertaken. Some earlier selected landmark references were included in the review. Search terms included: "alpha1-antitrypsin deficiency"; "liver disease"; "end-stage liver disease"; "liver transplantation" and "preventative management". Recommendations for the management of children with suspected or confirmed AAT deficiency were made according to the Strength of Recommendation Taxonomy scale.

FINDINGS

Liver complications arising from AAT deficiency result from the accumulation of mutated AAT protein within hepatocytes. Liver disease occurs in 10% of children, manifested by cholestasis, pruritus, poor feeding, hepatomegaly, and splenomegaly, but the presentation is highly variable. A diagnostic test for AAT deficiency is recommended for these children. Baseline liver function tests should be obtained to assess for liver involvement; however, the only curative treatment for AAT deficiency-associated liver disease is organ transplantation. Conclusion and Relevance: There should be a greater vigilance for AAT deficiency testing among pediatricians. Diagnosis should prompt assessment of liver involvement. Children with AATdeficiency- associated liver disease should be referred to a liver specialist and monitored throughout their lifetimes for the symptoms of AAT-deficiency-related pulmonary involvement.

Sex differences in alpha-1-antitrypsin deficiency lung disease-analysis from the German registry

Alpha-1-antitrypsin deficiency (AATD) is a rare condition with clinical manifestations of the lung and the liver. There is evidence that the gender affects the clinical presentation of non-AATD chronic obstructive lung disease (COPD). The aim of this study was to analyze gender-dependent disease pattern in AATD-based COPD. Data from 1066 individuals from the German AATD registry were analyzed by descriptive and analytical statistics. The AAT genotypes comprised 820 individuals with PiZZ (male 56%, female 45%), 109 with PI SZ (male 55%; female 45%), and others (n = 137). A subgroup of 422 patients with available post-bronchodilator FEV1% predicted was analyzed in detail after stratification in spirometric GOLD stages I-IV. The age of the registered individuals is 52.2 ± 13.4 years (male: 51.91 ± 13.86 years; female: 52.76 ± 13.39 years). Female patients with GOLD I-IV showed lower numbers of pack-years and lower BMI. The time between the first symptom and the establishment of the correct diagnosis was significantly longer in female (14.47 ± 16.46 years) as compared to male individuals (12.39 ± - 14.38 years, p = 0.04). In conclusion, the data of the registry allow to characterize the natural course of the disease and highlight differences in the clinical presentation of patients with AATD-dependent COPD.

Alpha-1 antitrypsin: a potent anti-inflammatory and potential novel therapeutic agent

Alpha-1 antitrypsin (AAT) has long been thought of as an important anti-protease in the lung where it is known to decrease the destructive effects of major proteases such as neutrophil elastase. In recent years, the perception of this protein in this simple one dimensional capacity as an anti-protease has evolved and it is now recognised that AAT has significant anti-inflammatory properties affecting a wide range of inflammatory cells, leading to its potential therapeutic use in a number of important diseases. This present review aims to discuss the described anti-inflammatory actions of AAT in modulating key immune cell functions, delineate known signalling pathways and specifically to identify the models of disease in which AAT has been shown to be effective as a therapy.

Pilot analysis of the plasma metabolite profiles associated with emphysematous Chronic Obstructive Pulmonary Disease phenotype

The current pilot study examined the hypothesis that cigarette smokers who developed an emphysematous phenotype of Chronic Obstructive Pulmonary Disease (COPD) were associated with distinctive patterns in their corresponding metabolomics profile as compared to those who did not. Peripheral blood plasma samples were collected from 38 subjects with different phenotypes of COPD. They were categorized into three groups: healthy non-smokers (n=16), smokers without emphysema (n=8), and smokers with emphysema (n=14). Ultra High Performance Liquid Chromatography/quadrupole-Time-of-Flight Mass Spectrometry techniques were used to identify a large number of metabolite markers (3534). Unsupervised clustering analysis accurately separated the smokers with emphysema from others without emphysema and demonstrated potentials of this metabolomics data. Subsequently predictive models were created with a supervised learning set, and these predictive models were found to be highly accurate in identifying the subjects with the emphysematous phenotype of COPD with excellent sensitivity and specificity. Our methodology provides a preliminary model that differentiates an emphysematous COPD phenotype from other COPD phenotypes on the basis of the metabolomics profiles. These results also suggest that the metabolomics profiling could potentially guide the characterization of relevant metabolites that leads to an emphysematous COPD phenotype.

Diagnostic delay and clinical modifiers in alpha-1 antitrypsin deficiency

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is one of the most prevalent inherited diseases in Whites, but identification of affected patients and establishment of the diagnosis is still unsatisfactory. This study assessed the latencies and numbers of physicians involved in identifying AATD patients, and the importance of smoking, vaccination status, and specific augmentation therapy on the course of the disease.

METHOD

Patients from Germany and Austria underwent a single written interview with 28 items. Five hundred and ninety-six patients were addressed and 44.9% replied.

RESULTS

The age at symptom onset was 39.1±10.1 years, and the diagnosis was established at the age of 45.1±10.9 years. From the 6-year delay in establishing the diagnosis, 1.4±1.7 (range 0.5-10.5) years were due to patients' reluctance to seek medical attention. There were 3.2±2.4 (range 1-13) physicians involved in establishing the diagnosis. Smoking was associated with an earlier onset of respiratory symptoms and lower exercise capacity. Vaccination against pneumococci and/or influenza, and augmentation therapy resulted in significantly fewer exacerbations and fewer emergency room visits. Airway infections and passive smoking during childhood were not found to influence the onset of respiratory symptoms.

CONCLUSIONS

In conclusion, there is still a large delay between symptom onset and AATD diagnosis. Smoking history, vaccination status, and augmentation therapy have an important impact on the course of the disease.

[Alpha1-antitrypsin deficiency]

Alpha(1)-antitrypsin deficiency is characterized by a pathologic reduction of the serum concentration of alpha(1)-antitrypsin, the most important antiprotease in man. It is one of the most common hereditary diseases in Caucasians. Approximately 2% of obstructive airway diseases are caused by alpha(1)-antitrypsin deficiency. Patients above 35 years may develop lung emphysema, especially in the lower lobes. Symptoms are those of chronic obstructive pulmonary disease such as cough, sputum expectoration, and progressive dyspnoea. Patients with homozygous defect often develop cholestatic hepatitis in the neonatal period. However, only few adult patients develop chronic liver disease up to liver cirrhosis with an elevated risk for malignant liver tumors. The diagnostic hallmark is the reduced serum concentration of alpha(1)-antitrypsin while genetic testing proves the defect. An early recognition of the disease is decisive for prophylactic and therapeutic measures. Smoking should be stopped immediately. Treatment of lung disease includes physiotherapy, antiobstructive and antiinflammatory medication, augmentation with human alpha(1)-antitrypsin and lung surgery including lung transplantation. Liver toxins should be avoided. Besides experimental therapeutic approaches, liver disease can only be treated by liver transplantation.