Alpha 1-antitrypsin deficiency natural history


 * Associate Editor-In-Chief:

Overview
Alpha 1-antitrypsin deficiency (A1AD) may be slow to manifest in symptom onset in newborns. As a patient ages, liver dysfunction and deterioration will occur. Mortality is directly related to the respiratory failure caused by a fall in forced expiratory volume.

Natural History
Respiratory failure accounts for ~ 62% of deaths, and complications of chronic liver disease for ~ 13%. The mean age of death in one study was 53 years old for nonsmokers and 40 years old for smokers, with only 16% surviving to 60 years old. This compares to ~ 85% surviving to 65 years old in the general population. Mortality is directly related to FEV1 (forced expiratory volume), and rises exponentially as FEV1 falls below 35% predicted. In a Danish study, asymptomatic nonsmokers, who were identified as relatives of symptomatic patients with alpha-1 AT had a normal life expectancy. This is consistent with the presence of a subgroup of patients with severe deficiency in alpha-1 AT who escape medical attention.
 * Within the first two decades of life, liver dysfunction tends to dominate the clinical picture, while lung function is generally preserved.
 * Two prospective studies have followed newborns identified at birth with blood screening for up to 16 years, and both showed no difference in lung function compared with controls.
 * After the first 20 years, however, lung function begins to deteriorate at the rate mentioned above.