Results of a case-detection programme for alpha1-antitrypsin deficiency in COPD patients.
Alpha1-antitrypsin (alpha1-AT) deficiency is an underdiagnosed condition in patients with chronic obstructive pulmonary disease (COPD). The present authors have conducted a nationwide case detection programme of alpha1-AT deficiency in unselected patients with COPD using dried blood spots. The first phase analysed samples from 971 patients by determining alpha1-AT concentrations and identifying the deficient Z allele by genotyping using rapid real-time PCR. The second phase analysed 1,166 samples with alpha1-AT concentrations and identified both the S and the Z allele, but only in samples with low alpha1-AT concentrations. A total of eight (0.37%) individuals with the severe deficiency PiZZ were detected. In addition, three patients were identified with the PiSZ genotype in the second phase (0.3%). The global cost of the programme was 41,512, which represents 19.42 per sample and 5,189 per PiZZ detected. A sensitivity analysis demonstrated that performing Z genotype to all samples would have resulted in increased costs of 28 per sample and 7,479.5 per PiZZ case identified. In conclusion, a case detection programme of alpha1-antitrypsin deficiency in patients with chronic obstructive pulmonary disease using dried blood spots is feasible and at a reasonable cost per case detected. Diagnostic yield and costs depend largely on inclusion criteria and the protocol for processing of samples.
de la Roza
C
C
Dept of Pneumology, Institut Clínic del Tòrax, Hospital Clínic, Red Respira, Barcelona 08036, Spain.
Rodríguez-Frías
F
F
Lara
B
B
Vidal
R
R
Jardí
R
R
Miravitlles
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003365:Costs and Cost Analysis; D005240:Feasibility Studies; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D000515:alpha 1-Antitrypsin / Q000032:analysis*; D019896:alpha 1-Antitrypsin Deficiency / Q000097:blood* / Q000150:complications / Q000175:diagnosis* / Q000235:genetics
D000515:alpha 1-Antitrypsin