PI*ZZ alpha-1 antitrypsin (AAT) deficiency poses risk for lung disease through 2 different mechanisms: a toxic loss of function in which deficient AAT levels cause a depleted proteolytic screen and, separately, a proinflammatory effect of Z polymers produced both by alveolar macrophages and by the liver. Ample data support the first mechanism, while the possible contribution of the second 2 proinflammatory mechanisms is currently unknown. Experience with a 74 year-old PI*ZZ female who underwent single lung transplantation and subsequent orthotopic liver transplantation (OLT) may shed light on the relative contributions of each of the potential mechanisms. Availability of multiple pulmonary function tests (PFT) measurements uniquely permitted calculation of rates of lung function change before and after OLT. The rate of forced expiratory volume in 1 second (FEV1) decline normalized post-OLT (from -60 to -21 ml/yr). Her course suggests that restoring the normal serum AAT levels or, alternately, eliminating liver-derived polymers, exerted a greater effect on preventing emphysema progression than local Z polymer production contributed to furthering emphysema.
Keywords: alpha-1 antitrypsin deficiency; emphysema; transplant.