In the unaffected individual the alpha-1 antitrypsin (a1at) protein is produced normally and secreted into the bloodstream. In the A1ATD affected person, the Z gene produces mutated forms of alpha-1, all of the mutated alpha-1 protein cannot be misfolded and secreted into the bloodstream. This causes the mutated alpha-1 to get trapped in liver cells and clump together, in turn causing toxic effects, this ongoing damage leads to further liver damage.
Notice the red globules on FIG. 1A. With are periodic acid-Schiff (PAS) stain, they are characteristic for alpha-1-antitrypsin (AAT) deficiency. More persons with AAT deficiency are likely to develop chronic obstructive pulmonary disease with panlobular emphysema.
The globules are collections of alpha-1-antitrypsin not being excreted from hepatocytes. This may eventually lead to chronic hepatitis and cirrhosis. Liver disease is more likely to occur in children with AAT deficiency, while lung disease occurs in adults