[Validation of a method for measuring the antielastolytic activity of human circulating alpha1-antitrypsin].

The existence of alpha-1 antitrypsin variants with apparently unremarkable phenotypes and serum concentrations, contrasting with a clinical picture suggestive of a severe deficiency, led us to investigate whether in these cases there was a reduction or even suppression of the capacity of alpha-1 antitrypsin to inhibit elastase. To this end, in two different laboratories, we adapted and validated a method for measuring the functional activity of alpha-1 antitrypsin, based on spectrophotometric kinetic analysis of the inhibition by serum alpha-1 antitrypsin of the hydrolytic activity of porcine pancreatic elastase on a chromogenic substrate. This method has proved to be robust, reproducible and transferable and made possible to define, on the basis of an analysis of a hospital population, a functionality index with a confidence interval comprised between 0.

[Screening for alpha1-antitrypsin deficiency using dried blood spot: Assessment of the first 20 months].

Introduction: Alpha1-antitrypsin deficiency is a predisposing factor for pulmonary disease and under-diagnosis is a significant problem. The results of a targeted screening in patients with respiratory symptoms possibly indicative of severe deficiency are reported here.

Methods: Data were collected from March 2016 to October 2017 on patients who had a capillary blood sample collected during a consultation with a pulmonologist and sent to the laboratory for processing to determine alpha1-antitrypsin concentration, phenotype and possibly genotype.

Assessment of liver fibrosis by transient elastography (Fibroscan) in patients with A1AT deficiency.

Background: Alpha-1-antitrypsin deficiency (A1ATD) is a common genetic condition which predisposes to emphysema and liver disorders. It is estimated that 10-15% of homozygous individuals for the Z allele (PiZZ) may develop liver fibrosis. The optimal modalities to detect liver disease in PiZZ adult patients need to be defined.

Liver disease related to alpha1-antitrypsin deficiency in French children: The DEFI-ALPHA cohort.

Background & Aims: To identify prognostic factors for liver disease in children with alpha-1 antitrypsin deficiency, irrespective of phenotype, using the DEFI-ALPHA cohort.

Methods: Retrospective, then prospective from 2010, multicentre study including children known to have alpha-1 antitrypsin blood concentration below 0.8 g/L, born in France since 1989.