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Rapid Screening for α 1 -Antitrypsin Deficiency in Patients with Chronic Obstructive Pulmonary Disease Using Dried Blood Specimens

2002; American Thoracic Society; Volume: 166; Issue: 6 Linguagem: Inglês

10.1164/rccm.2203025

1535-4970

F. Rodrı́guez, Rosendo Jardí, X. Costa, Montserrat Cotrina, R. Galimany, Rafael Vidal, Marc Miravitlles,

Insect Resistance and Genetics

We describe two reliable methods for high-throughput screening of proteinase inhibitor (PI) S and PI Z α1-antitrypsin (α1-AT) deficiency alleles from dried blood spot (DBS) specimens using the LightCycler fluorimetric analyzer. The method was used to study 72 patients with chronic obstructive pulmonary disease. Results were confirmed with DNA sequencing. The α1-AT concentration in DBS was determined with immune nephelometry. Sixteen patients (22%) showed no PI Z or PI S mutations. Five patients (7%) had a heterozygous genotype consisting of a PI S allele and a normal allele for the Z and S positions (non-S non-Z). Twenty-five patients (35%) had a heterozygous genotype consisting of a PI Z and a non-S non-Z allele. Two (3%) had the PI SS genotype, 2 (3%) the PI SZ, and 20 (28%) the PI ZZ. All patients with two normal α1-AT alleles and 10 heterozygous carriers of one normal and one deficient allele had α1-AT levels that fell within the α1-AT DBS normal range (1.8–3.1 mg/dl). Two patients with the rare PI MMmalton- and PI MMheerlen-deficient variants showed deficient α1-AT levels; PI S and PI Z were not detected. Processing 32 samples requires only 40 minutes. This single-step, cost-effective technology is optimal for working with small amounts of DNA, as are present in DBS. The method is suitable for large-scale screening, in cases where PI type is important.