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.