To investigate a new therapeutic strategy , with rapid corticosteroid dose tapering and limited cyclophosphamide ( CYC ) exposure , for older patients with systemic necrotizing vasculitides ( SNVs ; polyarteritis nodosa -LSB- PAN -RSB- , granulomatosis with polyangiitis -LSB- Wegnener 's -RSB- -LSB- GPA -RSB- , microscopic polyangiitis -LSB- MPA -RSB- , or eosinophilic GPA -LSB- Churg-Strauss -RSB- -LSB- EGPA -RSB- ) .