Nitric oxide production and immunoglobulin deposition in leptospiral hemorrhagic respiratory failure.

Diffuse pulmonary hemorrhage leading to death is a syndrome which may develop in leptospirosis, but its pathophysiology is not well documented. We report an autopsy case of leptospirosis. A healthy 41-year-old man presented with low back myalgia, dry cough and fever for 4 days and a normal chest X-ray on admission. Acute respiratory failure developed hours later. Profuse bloody fluid appeared in the endotracheal tube immediately after intubation. Chest X-ray showed whiteness across all lung fields. He died of persistent shock 16 h after the onset of acute respiratory failure. Autopsy revealed diffuse pulmonary hemorrhage with hyaline-membrane formation, myocarditis, interstitial nephritis and hepatitis. Silver stain of lung and kidney tissue demonstrated leptospires. Immunohistochemical staining showed inducible nitric oxide synthase in alveolar macrophages. Immunofluorescein staining showed immunoglobulin in alveolar septum and alveolar space. This case suggests that hemorrhagic diffuse alveolar damage with persistent shock is related to over-production of nitric oxide and immunoglobulin deposition in fatal leptospirosis.