Similar to aprotinin, α1-Antitrypsin (AAT) is a 52-kDa circulating serine protease inhibitor classified as a SERPIN protein. Besides its ability to inhibit serine proteases, accumulating data suggest that AAT-1 possesses independent anti-inflammatory and tissue-protective effects (3). AAT-1 modifies dendritic cell maturation and promotes regulatory T-cell differentiation, induces interleukin (IL)-1 receptor antagonist and IL-10 release, protects various cell types from cell death, inhibits caspases-1 and -3 activities and inhibits IL-1 production and activity (4). Contradictory to classic immunosuppressants, AAT-1 allows undeterred isolated T-lymphocyte responses (5).These effects have been repeatedly corroborated.