The challenge of detecting alpha-1 antitrypsin deficiency.

Alpha-1 antitrypsin deficiency (AATD) is relatively common but under-recognized. Indeed, fewer than 10% of the estimated 100,000 Americans with AATD have been diagnosed currently, with common reports of long delays between initial symptoms and first detection and the need to see multiple physicians before diagnosis. Because detection can confer benefits (e.g., identification of at-risk family members, lower smoking likelihood, consideration of augmentation therapy), targeted detection of AATD in at-risk groups such as all symptomatic adults with COPD has been endorsed. Two general approaches to detection have been studied: population-based screening (in which testing is performed in a group for whom no increased risk of having AATD exists) and targeted detection or case-finding (in which testing is confined to those with an attributable condition such as COPD or chronic liver disease). Studies to date have suggested that population-based screening is not cost-effective, whereas targeted detection of AATD has been advocated by official society guidelines. Efforts to enhance detection of AATD individuals have included various approaches, including educational campaigns, provision of free test kits, issuance of reminders with medical reports or within an electronic medical record, and empowering respiratory therapists to conduct testing for AATD in pulmonary function laboratories. Such programs have identified individuals with severe deficiency of alpha-1 antitrypsin in up to 12% of subjects, with considerable variation across series by testing criteria. Overall, the persistence of under-recognition of AATD underscores the need for continued efforts to optimize detection of this potentially debilitating genetic disease.