Alpha-1 Antitrypsin Deficiency

A patient with emphysema at an unusually young age, emphysema despite never smoking, or emphysema that is most marked at the lung bases does not fit the usual smoking-related pattern. Add unexplained bronchiectasis, chronic liver disease, neonatal cholestasis, or a family history of early lung or liver disease, and alpha-1 antitrypsin deficiency (AATD) becomes a diagnosis to actively investigate rather than a rare possibility to remember later. The clinical model is deliberately two-part. Low circulating alpha-1 antitrypsin leaves the lungs exposed to neutrophil elastase; abnormal protein retained inside hepatocytes injures the liver. This is why weekly replacement can protect the lung but cannot treat the liver, and why smoking cessation remains more important than any disease-specific infusion.