Table 1. Milder deficiency genotypes, alpha-1 antitrypsin (AAT) levels, and risk of disease.
| Genotype | *Average AAT level13 | Risk of disease | References | |
|---|---|---|---|---|
| SZ | 9–15 µM | 45–80 mg/dL | COPD (related to smoking or occupational exposure; 3x > PiMM) Lung function decline (DLCO > FEV1) Apical emphysema dominance, with less severe disease than PiZZ Risk factor for chronic liver disease |
5,9–12 |
| MZ | 13–23 µM | 66–120 mg/dL | Higher risk of emphysema compared to PiMM Increased risk of COPD in smokers/ex-smokers Lung function decline (FEV1 > DLCO) Higher transaminase levels Modifier of chronic liver disease (alcoholic cirrhosis, non-alcoholic liver disease, or cirrhosis) |
4,9,14–17 |
| SS | 14–20 µM | 70–105 mg/dL | Obstructive lung disease (COPD; asthma) Minor risk liver cirrhosis in alcohol abusers |
4,18 |
| MS | 19–35 µM | 100–180 mg/dL | Without lung or liver risk disease | 13 |
AAT, alpha-1 antitrypsin; COPD, chronic obstructive pulmonary disease; DLCO, diffusing capacity of lung for carbon monoxide; FEV1, forced expiratory volume in 1 second
*Serum levels given are measured using commercial standard (mg/dL) and the purified standard (µM)