Diagnosis and management of ANCA-associated vasculitis in Intensive Care

Abstract

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are rare and potentially severe diseases, with challenging diagnosis, that intensivists must recognize promptly to initiate appropriate induction therapy and improve patient outcomes. AAV primarily affect small vessels and include three main entities: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). AAV can lead to life-threatening complications such as diffuse alveolar hemorrhage, severe hyper-eosinophilic asthma exacerbations, rapidly progressive glomerulonephritis, gastrointestinal involvement (ischemia, perforation, hemorrhage), or cardiac manifestations, requiring admission in intensive care unit.

Diagnosis relies on a combination of characteristic clinical manifestations, biological findings (presence of anti-PR3 or anti-MPO ANCA in >90% of GPA and MPA cases, but only 40% of EGPA cases), and sometimes histological evidence. Severe forms require treatment with three days of intravenous methylprednisolone pulses, followed by tapering intravenous glucocorticoids (initially 1 mg/kg), combined with immunosuppressive therapy (typically cyclophosphamide for critical forms or rituximab). The role of plasma exchange remains controversial and is reserved for the most critical cases.