Baseline characteristics of enrollees in the national heart, lung and blood institute registry of alpha(1)-antitrypsin deficiency

Objective: alpha(1)-Antitrypsin (alpha(1)-AT) deficiency is a hereditary disorder characterized by a high risk for the development of emphysema at an early age. In 1988, the National Heart, Lung and Blood Institute, National Institutes of Health, initiated a registry of individuals with alpha(1)-AT deficiency to help define the natural history and clinical course of this disorder. This article describes demographic and clinical characteristics of subjects enrolled in the Registry at baseline. Design: Prospective longitudinal natural history study. Setting: Thirty-seven clinical centers in the United States (36 centers) and Canada (one center). Patients: There were 1,129 subjects 18 years or older with severe deficiency of alpha(1)-AT, defined as having serum alpha(1)-AT levels less than or equal to 11 mu mol/L confirmed by a Central Phenotyping Laboratory, or a ZZ or ZNull genotype identified by genomic DNA analysis. Results: Most enrollees were symptomatic white subjects in their fourth to sixth decade, with a ZZ phenotype, a history of having smoked cigarettes, and pulmonary function tests demonstrating a pattern consistent with emphysema. Interestingly, only a small percentage were current smokers on enrollment, suggesting that this population is amenable to smoking cessation. A subgroup of individuals in the Registry with relatively normal lung function were younger, more likely to have never smoked and more likely to have come to medical attention owing to a family history of alpha(1)-AT deficiency rather than symptomatic involvement. Conclusions: These results emphasize the need for increased awareness and early detection of alpha(1)-AT deficiency. In this endeavor, dissemination of the information contained in the Registry to health-care professionals and the general population, along with initiation of appropriate preventative measures before significant lung damage has occurred, could have considerable benefits for individuals with this condition.