First observation of neutrophil extracellular traps in human leptospirosis

Leptospirosis is the most important global zoonosis and is caused by pathogenic spirochetes of the genus Leptospira . Human leptospirosis ranges in severity from a mild, self-limited febrile illness to a fulminant life-threatening one but their pathogenesis is still unclear. The extracellular release of the nuclear DNA of neutrophils, called NETs, upon activation by microbes is a pathogen-killing mechanism of neutrophils described in 2004 although its presence in human pathology have been observed only very recently. We report a case of fatal fulminant leptospirosis with associated severe pulmonary involvement and shown for the first time, evidence of the presence of NETs in the lung tissue.