Diagnosing Alpha-1-Antitrypsin Deficiency Using A PCR/Luminescence-Based Technology

Abstract

Purpose: Alpha-1-antitrypsin deficiency (AATD) is a rare hereditary condition resulting from the mutations in the SERPINA1 (serine protease inhibitor) gene and is characterized by low circulating levels of the alpha-1 antitrypsin (AAT) protein. The traditional algorithm for laboratory testing of AATD involves the analysis of AAT concentrations (nephelometry), phenotyping (isoelectric focusing, IEF), and genotyping (polymerase chain reaction, PCR); in selected cases, full sequencing of the SERPINA1 gene can be undertaken. New technologies arise that may make diagnosis easier and faster. Methods: We developed and evaluated a new diagnostic algorithm based on Luminex xMAP (multi-analyte profiling) technology using Progenika A1AT Genotyping Test. In an initial learning phase, 1979 samples from individuals suspected of having AATD were examined by both, a traditional and a “new” algorithm. In a second phase, 1133 samples were analyzed with the Luminex xMAP only. Results: By introducing a Luminex xMAP based algorithm, we were able to simultaneously identify 14 mutations in SERPINA1 gene (instead of two- S and Z-by using our old algorithm). Although the quantity of IEF assays remained unchanged, the nephelometric measurements and sequencing were reduced by 79% and 63.4%, respectively. Conclusion: The new method is convenient, fast and user-friendly. The application of the Luminex xMAP technology can simplify and shorten the diagnostic workup of patients with suspected AATD.