P116 | An unusual case of acute respiratory failure

Premises: Hemorrhagic alveolitis is a clinical syndrome characterized by acute onset, caused by diffuse alveolar damage with worsening respiratory failure. It is a condition frequently associated with hematological, systemic autoimmune, or infectious diseases.Case Description: A 92-year-old man admitted for hemoptysis and acute respiratory failure in the context of initial heart failure and a lung infection. Upon admission, he was treated with intravenous diuretic and steroid therapy, in addition to antibiotic therapy and tranexamic acid. Given the distribution of the opacities (bilateral and diffuse), HRTC and bronchoscopy with BAL were requested. At the EEC, I observed signs of anemia and worsening acute renal failure. Due to suspected hemorrhagic alveolitis, microbiological (negative results) and immunological investigations were requested, which revealed a high-titer positivity for anti-MPO (pANCA). Urine test: presence of non-selective proteinuria. The diagnosis was ANCA-associated vasculitis, microscopic polyangiitis type, with pulmonary and renal involvement. Steroid therapy was initiated with prednisone 1 mg/kg and rituximab 375 mg/m2 for four weekly administrations. The ENG AAII confirmed a bilateral sensory-motor polyneuropathy.Conclusions: Microscopic polyangiitis is an ANCA-associated vasculitis that most frequently presents with pulmonary involvement (hemorrhagic alveolitis), renal involvement (rapidly progressive glomerulonephritis), and neurological involvement (neuropathy). The mortality rate remains high (>50%).