Irish scientists based at Beaumont Hospital have been involved in a multicentre study to determine the first ever international standard for alpha-1 antitrypsin. This study will make it easier for research groups and pharmaceutical companies to assess the activity and potency of different preparations of alpha-1 antitrypsin being used as a therapeutic agent.

International Collaborative Study To Establish The 1st International (WHO) Standard For Alpha-1 Antitrypsin

Craig Thelwell¹, Peter Rigsby² and Colin Longstaff^1
1Biotherapeutics Group, Haemostasis Section and ²Biostatistics Division, National Institute for Biological Standards and Control, South Mimms, Herts EN6 3QG, England.

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 in 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.

A copy of the full publication can be viewed here.