Pharmacokinetic Study of Rituximab Induction Regimen in ANCA-associated Vasculitis
Pharmacokinetic Study of Rituximab Induction Regimen in ANCA-associated Vasculitis
The aim of the investigators' study is to evaluate whether monitoring serum rituximab levels
 could be an interesting tool in the follow-up of ANCA-associated vasculitis patients.

 All consecutive patients, hospitalized for a new diagnosis of ANCA-associated vasculitis or
 the relapse of a known ANCA-associated vasculitis, in which the decision to start an
 induction regimen with rituximab has been taken, will be included.

 Serum rituximab levels (along with serum anti-rituximab antibodies levels) will be determined
 (at M+1 and M+3) and the correlation with clinical outcome at M+6 will be analyzed.
Inclusion Criteria:

 -  Age > 18 years

 -  Granulomatosis with polyangiitis or microscopic polyangiitis (according to Chapel Hill
 criterions), with or without detectable ANCA

 -  Decision taken to start an induction regimen with rituximab

 -  Informed and having signed the study consent form

 -  If of child-bearing potential, female patients will have use an effective method of
 contraception during RTX (rituximab) treatment and in the 12 months following RTX
 treatment stop

 -  no-breast-feeding during RTX treatment and in the 12 months following RTX treatment
 stop

 Exclusion Criteria:

 -  Other primary or secondary systemic vasculitis

 -  Incapacity or refusal to sign the informed consent form

 -  Incapacity or refusal to adhere to treatment or perform the follow-up examinations
 required by the study

 -  Allergy, documented hypersensitivity or contraindication to the medications used in
 the present study (corticosteroids, rituximab)

 -  severe active infection

 -  Patient with severe heart failure (stage NYHA IV) or any other unstable heart disease
 Pregnancy, except for cases where the expected benefit oj treatment seems to surpass
 the potential risks

 -  Patients with active hepatitis B

 -  Any live vaccine within four weeks prior to the first infusion of RTX