SCINTIGRAPHIC DOCUMENTATION OF ALPHA-1-ANTITRYPSIN IN DEFICIENT PIZZ PATIENTS

PiZZ-deficient patients affected by a severe panlobular emphysema were treated with an infusion of industrial concentrates of purified alpha 1-antitrypsin (AAT). A treatment protocol was followed and the pharmac okinetic parameters were determined. The aim of this investigation was to consider the tissue distribution of AAT injected into untreated an d treated patients, as well as into controls, in order to locate the l abelled protein and map the kinetics of the protein deposit. Scintigra phies carried out on PiZZ patients and on controls confirmed a 3-pool pharmacokinetic model of AAT distribution. Three organs accounted for the predominant deposition of AAT: the liver, lungs and a very limited area of the upper digestive tract. At time 0, the distribution of the protein differed between controls and untreated patients. After 6 mon ths of replacement therapy, the tissue distribution of AAT among treat ed and untreated PiZZ-deficient patients was not similar. The liver is one of the essential organs affected by the infusion of AAT. This stu dy demonstrated that the digestive tissues are also affected by this r eplacement therapy. These observations should be useful in predicting tissue metabolism of the injected preparation, particularly when alter native routes of AAT administration are now possible.