Study of One Protein Implicated in Wegener Disease
Study of One Protein Implicated in Wegener Disease
The investigators recently showed an abnormal expansion of NK-like CD4+ T cells in Wegener's
 granulomatosis (WG), mainly in the diffuse vasculitis presentation. These cells expressed an
 assortment of activating NK cell receptors and their signaling partners, in particular DAP12.
 The investigators hypothesize that DAP12, or a downstream signaling target of DAP12, is the
 missing link between the different cell components involved in WG (neutrophils, macrophages,
 CD4 T cells).
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.
Inclusion Criteria:

 -  Group 1: WG, with granulomatous lesions limited to upper airway or lungs and no
 evidence of generalized vasculitis ,± biopsy, ± anti-PR3 ANCA

 -  Group 2: WG with granulomatous lesions plus vasculitis expression (renal,
 neurological, skin, gut or heart involvement), ± biopsy, ± anti-PR3 ANCA

 -  Group 3: Necrotizing vasculitis with no granulomatous lesions, ± PAUCI immune
 glomerulonephritis, ± anti-MPO ANCA

 -  Group 4: clinical presentation compatible with sarcoidosis, ± biopsy, ± ECA elevated ±
 tuberculin anergy

 Exclusion Criteria:

 -  <18 years

 -  Pregnancy or breastfeeding

 -  Absence of signed informed consent

 -  No affiliation to insurance