α‑1 Antitrypsin is a potential target of inflammation and immunomodulation (Review).

α‑1 Antitrypsin (AAT) is an acute phase protein encoded by the serine protease inhibitor family A member 1 gene. This multifunctional protein serves several roles, including anti‑inflammatory, antibacterial, antiapoptotic and immune regulatory functions. The primary role of AAT is to protect tissues and organs from protease‑induced damage due to its function as a serine protease inhibitor. AAT is associated with the development of lung inflammation, liver inflammation and immune‑mediated inflammatory diseases, which are influenced by environmental and genetic factors. For instance, AAT acts as an anti‑inflammatory protein to prevent and reverse type I diabetes. The present study briefly reviewed the molecular properties and mechanisms of AAT, as well as advances in the study of lung, liver and inflammatory diseases associated with AAT. The potential of AAT as a diagnostic and therapeutic target for inflammatory and immune‑mediated inflammatory diseases was reviewed. In addition, the damaging and protective effects of AAT, and its effects on organ function were discussed.