Accumulation of endostatin/collagenXVIII in brains of patients who died with cerebral malaria.

Endostatin is a 20 kDa C-terminal fragment of collagenXVIII that, when added exogenously, inhibits angiogenesis by inducing apoptosis of endothelial cells. In cerebral malaria (CM), blood-brain barrier dysfunction is a hallmark alteration in the formation of edema, inflammation, hemorrhage and Dürck's granulomas that are thought to represent the histopathological basis of neurological impairments observed in CM patients. We now analyzed endostatin/collagenXVIII expression in brains of seven patients who died with CM and in seven control patients by immunohistochemistry double-labeling experiments. Endostatin/collagenXVIII immunoreactive macrophages/microglial cells accumulated predominantly in Dürck's granulomas. Some immunoreactivity was observed in macrophages located in cerebral capillaries with deposition of malarial pigment and sequestration, but almost no immunoreactivity was detected in ring hemorrhages. Focal accumulation of endostatin/collagenXVIII in granulomas but not in ring hemorrhages of CM brains suggests a novel process that is involved in the destruction of endothelial cells at the time of Dürck's granuloma formation.