355. FACTORS PREDICTING SEVERE INFECTIONS IN PATIENTS WITH SYSTEMIC NECROTIZING VASCULITIDES BASED ON DATA FROM 733 PATIENTS ENROLLED IN RANDOMIZED–CONTROLLED TRIALS. (29th March 2019) - Lafarge, Antoine; Pagnoux, Christian; Puéchal, Xavier; Samson, Maxime; Hamidou, Mohamed; Karras, Alexandre; Quemeneur, Thomas; Groh, Matthieu; Mouthon, Luc; Guillevin, Loïc; Terrier, Benjamin; ,