Study of One Protein Implicated in Wegener Disease

The investigators will test our hypothesis of "DAP-12 gain-of-function" by quantitative (mRNA and protein) and qualitative (DNA, signaling and cellular activation) analysis of the DAP12 signaling pathway in WG patients with localized (group 1; n=30) or diffuse WG (group 2; n=30) by comparison with patients with micro polyangitis (group 3; n=30), or with sarcoidosis ( group 4; n=30), and healthy blood donors (group 5; n=30). Blood samples will be collected during a routine medical visit. These results may help to design future therapeutic strategies based on modulation of specific intra-cellular pathways involved in the disease.