Identification of individuals with alpha-1-antitrypsin deficiency by a targeted screening program.

Background: Alpha-1-antitrypsin deficiency (AATD) is significantly underdiagnosed. The early detection of AATD would enable affected persons to make lifestyle changes such as quitting smoking. It was the aim of the study to determine whether the combination of an awareness program with the offer of a cost-free diagnostic test results in the identification of a significant number of individuals with severe AATD.
Methodology: We combined a series of measures to promote awareness with the offer of a diagnostic test at no charge. Test blood was applied to a filter paper and sent to our laboratory. The level of AAT was measured by nephelometry, the presence of the S- or Z-allele was determined by PCR, and phenotyping was performed by isoelectric focusing.
Results: During 37 months 17688 testing kits were distributed and 2722 were sent back to our laboratory. We identified 335 patients with severe AATD including 16 individuals with rare genotypes. Prescreening by determining the AAT serum levels by the submitting physician increased the detection rate as compared to similar programs that screened unselected individuals.
Summary: These data show that the combination of an awareness program with the offer of free diagnostic testing results in the identification of a large number individuals with severe AATD.