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| International Collaborative Study To Establish The 1St International (Who) Standard For Alpha-1-Antitrypsin |
| Monday, 24 November 2008 12:54 |
Craig Thelwell1, Peter Rigsby2 and Colin Longstaff11Biotherapeutics Group, Haemostasis Section and 2Biostatistics Division, National Institute for Biological Standards and Control, South Mimms, Herts EN6 3QG, UK SUMMARY An international collaborative study was organised to establish the 1st International Standard (IS) for Alpha-1-Antitrypsin (AAT) as agreed at the Alpha-1 Foundation Workshop, April 2005, Cincinnati, USA. The study involved 15 laboratories from 10 different countries. Laboratories were provided with detailed methods and critical reagents and were asked to measure the potency of four candidate standards (A, 05/150; B, 05/152; C, 05/162 and D, 05/172). In addition laboratories with relevant experience were invited to carry out extended characterisation of the materials, including total protein and antigen content for which an additional reference preparation was provided. Analysis of the data indicated that any of the candidates would be suitable based on potency determination; however candidate C had a slight advantage based on filling data. It is therefore proposed that candidate C (05/162) be adopted as the 1st International Standard for Alpha-1-Antitrypsin with a potency of 243 nmoles (12.4 mg) active AAT per ampoule. |
Alpha-1 Antitrypsin is an important protein produced by the liver, which is released into the bloodstream and travels to the lungs. Once inside the lungs it provides protection from the destructive effects of infections and harmful irritants, particularly tobacco smoke.
Alpha-1 antitrypsin deficiency (Alpha-1) is a genetic condition which, along with cystic fibrosis, is the commonest genetic lung disease in Ireland. It severely affects more than 2,000 people nationally, with another 10,000 individuals also at risk of lung and liver disease. It is the only proven genetic risk factor for COPD.