Diffuse alveolar hemorrhage: how relevant is etiology?

Abstract

Background: Diffuse Alveolar Hemorrhage (DAH) is a rare and potentially life-threatening clinical syndrome whose early recognition is essential. Objectives: Characterization of patients with DAH and comparison of presentation and evolution of the disease according to etiology. Methods: We retrospectively reviewed the clinical records of patients admitted to our hospital over a 7-year period with DAH. Criteria for DAH (1+2): 1 - hemoptysis and/or pulmonary infiltrates and/or anemia (DAH triad); 2 - hemorrhagic bronchoalveolar lavage (BAL) or siderophagic alveolitis. DAH was grouped in immune and nonimmune and the course of disease was compared. Results: We included 24 patients admitted with DAH, of which 11 had an immune cause: p-ANCA vasculitis (n=7), Systemic Lupus Erythematosus (n=2), c-ANCA vasculitis (n=1), Rheumatoid Arthritis (n=1) and 13 had a nonimmune cause: heart disease (n=6), amiodarone toxicity (n=2), clotting disorder (n=2), cannabis toxicity (n=1), S. aureus infection (n=1) and idiopathic (n=1). Patients with nonimmune DAH were significantly older than those with immune DAH (67.9±18.1 vs 56.6±18.8 years, p=0.042). DAH triad was observed in 54% of all patients, hemoptysis in 67%, anemia in 79%, and pulmonary infiltrates in all cases. Patients with immune DAH had more frequently pulmonary-renal syndrome (p<0.001), kidney failure (p=0.048), shock (p=0.049) and needed more frequently admition in ICU (p=0.039) and blood transfusion (p=0.043). Hospital length of stay was superior in immune group (29.5±20.0 vs 19.5±14.3 days, p=0.047). In-hospital mortality was exclusive to immune DAH (12.5%). Conclusions: Patients with DAH due to immune causes were significantly younger, had more severe presentations of the disease and worst outcomes.