Detection of AAT in ex-vivo cultured BECs. ( A ) SDS-PAGE and Western blot analysis using an antibody to detect total AAT in 20 μl of 10x concentrated culture media from a 72-hour culture of ex vivo BECs from five patients homozygous for M-AAT and four patients homozygous for Z-AAT. Purified human serum AAT (h-AAT) served as positive control. A typical fluorogram from three independent experiments, which gave superimposable results, is shown. ( B ) Cell culture media from a 72-hour culture of ex vivo BECs from six patients homozygous for M-AAT and seven patients homozygous for Z-AAT were concentrated 10 times, opportunely diluted to a final concentration of 10 μg/ml of AAT as assessed by an ELISA for total AAT, and were analyzed by ELISA using the antipolymeric AAT antibody ATZ11. . * P = 0.01 Mann–Whitney U test. Definition of abbreviations: AAT = alpha-1 antitrypsin; BEC = bronchial epithelial cell; h-AAT = human serum AAT; PAGE = polyacrylamide gel electrophoresis; ELISA = enzyme-linked immunosorbent assay.