Besides liver cells, A1PI is produced in bone marrow, by lymphocytic and monocytic cells in lymphoid tissue, and by the Paneth cells of the gut.Inactivation of A1AT by enzymes other than elastase due to inflammation/infection causes the migration of T cells to halt precisely at the site where the pathologic insult exists. This suggests a role for α1PI not only in locomotion of lymphocytes through tissue, but as a consequence of infection, a primary role as a sentinel in immune vigilance.A1AT is both an endogenous protease inhibitor and an exogenous one used as medication. The pharmaceutical form is purified from human donor blood and is sold under the nonproprietary name alpha1–proteinase inhibitor (human) and under various trade names (including  Aralast NP, Glassia, Prolastin, Prolastin-C, and Zemaira). Recombinant versions are also available but are currently used in medical research more than as medication. Function
A1AT is a 52-kDa serpin and, in medicine, it is considered the most prominent serpin; the terms α1-antitrypsin and protease inhibitor (Pi) are often used interchangeably. Most serpins inactivate enzymes by binding to them covalently. These enzymes are released locally in relatively low concentrations where they are immediately cleared by proteins such as A1AT. In the acute phase reaction, a further elevation is required to "limit" the damage caused by activated neutrophil granulocytes and their enzyme elastase, which breaks down the connective tissue fiber elastin.
China officially apologized for early slowness in dealing with the SARS epidemic.The viral outbreak was subsequently genetically traced to a colony of cave-dwelling horseshoe bats in Xiyang Yi Ethnic Township, Yunnan.The outbreak first came to the attention of the international medical community on 27 November 2002, when Canadas Global Public Health Intelligence Network (GPHIN), an electronic warning system that is part of the World Health Organizations Global Outbreak Alert and Response Network (GOARN), picked up reports of a "flu outbreak" in China through Internet media monitoring and analysis and sent them to the WHO. While GPHINs capability had recently been upgraded to enable Arabic, Chinese, English, French, Russian, and Spanish translation, the system was limited to English or French in presenting this information. Thus, while the first reports of an unusual outbreak were in Chinese, an English report was not generated until 21 January 2003. The first super-spreader was admitted to the Sun Yat-sen Memorial Hospital in Guangzhou on 31 January, which soon spread the disease to nearby hospitals.In early April 2003, after a prominent physician, Jiang Yanyong, pushed to report the danger to China, there appeared to be a change in official policy when SARS began to receive a much greater prominence in the official media. Some have directly attributed this to the death of an American teacher, James Earl Salisbury, in Hong Kong. It was around this same time that Jiang Yanyong made accusations regarding the undercounting of cases in Beijing military hospitals.