The invention relates to the use of an immunologically reactive microbial transglutaminase or its immunologically reactive parts or analogues, which are present in a complex with gliadin or its immunologically reactive parts or analogues, for the diagnosis and/or therapy control of coeliac disease or sprue as well as gluten sensitivity, and a kit for determining the diagnosis and/or therapy control of coeliac disease or sprue as well as of gluten sensitivity, by means of the previously mentioned complex.
