Clinical forms	Kidney function	Immunosuppressant and/or immunomodulator treatment combined with corticosteroid therapy
Form not involving the functional or vital prognosis, short or medium term OR Form involving the functional prognosis, short or medium term (renal impairment)	Creatinine < 350 µmol/l or GFR > 15 ml/min	First line: Cyclophosphamide IV or Rituximab
Form involving short-term functional prognosis (renal impairment)	Creatinine > 350 µmol/l or GFR < 15 ml/min	First line: Cyclophosphamide IV Second line: Rituximab Even a combination of cyclophosphamide IV + rituximab (regiment according to the RITUXVAS protocol) to be discussed on a case-by-case basis Related treatments: Plasma exchanges may be offered on a case-by-case basis
Severe form involving a threat to life in the very short term (severe renal impairment and/or severe alveolar hemorrhage*)	Creatinine > 500 µmol/l or GFR < 10 ml/min	First line: Cyclophosphamide IV Second line: Rituximab Even a combination of cyclophosphamide IV + rituximab (scheme according to the RITUXVAS protocol) to be discussed on a case-by-case basis Related treatments: Plasma exchange could have a beneficial impact on renal survival and the speed of resolution of an alveolar hemorrhage and should be discussed on a case-by-case basis Mechanical ventilation, if necessary
A predominantly granulomatous form with a functional or vital prognosis involved (orbital mass compressing the optic nerve, symptomatic tracheal stenosis)	Regardless of kidney function	First line: Cyclophosphamide IV or Rituximab Second line: Combination of rituximab + methotrexate treatment (unless there is kidney failure, in the absence of scientific evidence) or Cyclophosphamide PO To be discussed with a reference or competence center

*A severe alveolar hemorrhage is defined by the existence of acute respiratory distress requiring high flow oxygen therapy and/or mechanical ventilation.