Alpha-1 antitrypsin deficiency in Adult
Prevalence varies considerably globally; however, it is estimated that approximately 3 million people worldwide are genotypically severely AAT deficient, and nearly 100 000 of those individuals are in the United States.
Symptoms and complications vary. Patients may have increased risk for chronic kidney disease, diabetes, metabolic alterations, ANCA-associated vasculitis, gallstone disease, emphysema, chronic obstructive pulmonary disease (COPD) (especially current and former smokers), cystic fibrosis–associated liver disease with portal hypertension, nonalcoholic fatty liver disease cirrhosis, and advanced liver fibrosis.
Patients presenting within the first four decades of life are more commonly at risk of suffering complications due to liver dysfunction. Cigarette smoking is one of the strongest drivers of rate of decline in lung function and consequently increases risk of death due to respiratory failure. Studies show that as many as 40% of AATD patients with mutations causing "toxic gain of function" accumulation of AAT in hepatocytes demonstrate histologically significant liver injury and cirrhosis at time of death. Male sex and obesity may convey an increased risk of progression of liver injury to progressive hepatic failure over other traditional liver risk factors, such as alcohol use disorder and viral hepatitis. Respiratory failure and liver disease are major causes of mortality in severely deficient patients (72% and 10%, respectively).
E88.01 – Alpha-1 Antitrypsin Deficiency
30188007 – Alpha-1 Antitrypsin Deficiency
Differential Diagnosis & Pitfalls
- Cystic fibrosis
- Pulmonary Langerhans cell histiocytosis
- Birt-Hogg-Dube syndrome
- Hypersensitivity pneumonitis
- Desquamative interstitial pneumonia
- Respiratory bronchiolitis
- Post-traumatic lung pseudocysts
- Ehlers-Danlos syndrome
- Lymphocytic interstitial pneumonia
- Pneumocystis jirovecii pneumonia