Dépistage du déficit en alpha1-antitrypsine sur sang capillaire recueilli sur papier-filtre : bilan des 20 premiers mois

Abstract

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. Data were collected from March 2016to October 2017on 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. In 20months, 3728test kits were requested by 566pulmonologists and 718 (19%) specimens sent: among these, 708were analyzable and 613were accompanied by clinical information. Of the 708samples, 70% had no phenotype associated with quantitative alpha1-antitrypsin deficiency, 7% had a phenotype associated with a severe deficiency and 23% had a phenotype associated with an intermediate deficiency. One hundred and eight patients carried at least one PI*Z allele which is considered to be a risk factor for liver disease. The results of this targeted screening program for alpha1-antitrypsin deficiency using a dried capillary blood sample reflect improvement in early diagnosis of this deficiency in lung disease with good adherence of the pulmonologists to this awareness campaign.