[Infectious events during the course of systemic necrotizing vasculitis: a retrospective study of 82 cases].

Purpose: The aim of this study was to assess the infections occurring in a series of 82 patients followed for a systemic necrotizing vasculitis and to determine potential risk factors.

Methods: We studied retrospectively the medical files of 23 Churg and Strauss syndrome, 18 periarteritis nodosa, 14 microscopic polyangiitis, and 27 granulomatosis with polyangiitis, over a 15-year period. Infection delay corresponded to the period from treatment to first infection or between two infections.

Results: A total of 61 patients developed 147 infections. Causal agent was identified in 70 cases, 42 were bacterial, 20 viral and 8 fungal. Bronchopneumonia was the most frequent infection (43 %). Sixty-two percent of infections occurred within 2 years after vasculitis diagnosis. Seven infections were major, requiring intensive care, with one infection-death related. Pneumocystis prophylaxis concerned 75 % of patients on cyclophosphamide. Significant factors reducing infection delay were initial hypergammaglobulinemia, hypoalbuminemia, lymphopenia, as well as cyclophosphamide and methotrexate treatment. Large quantities of corticosteroids, cyclophosphamide or azathioprine increased infection delay. This result underlines the early occurrence of infectious complications during vasculitis course.

Conclusion: Infectious events occurring in systemic necrotizing vasculitis are frequent and occurs early in disease course, and could be prevented with simple prophylactic measures. Vasculitis relapse and infection share similarities and this require permanent clinical vigilance.