Clinical-histopathological correlation of the abnormal retinal vessels in cerebral malaria

Background: Clinically abnormal retinal vessels unique to cerebral malaria have previously been shown to be associated with a poor outcome in African children. There have been no studies of the histopathological correlates of these vessels. Design: This is a descriptive study of the clinical-histopathological correlates of the retinal vessels of 11 children who died with cerebral malaria. Results: The retinal vessels in children with cerebral malaria contained many parasitized red blood cells; these cells tended to cluster at the periphery of vessels or, in the case of capillaries, to fill the vessel. Those with late-stage parasites had markedly reduced amounts of hemoglobin. The pattern of dehemoglobinization corresponds to the pattern of clinically abnormal vessels. Conclusions: The sequestration of late-stage parasitized red blood cells with reduced amounts of hemoglobin accounts for the unique white and pale orange retinal vessels seen in cerebral malaria. Clinical examination of these 'marked' vessels offers a method to monitor a basic pathophysiological process of cerebral malaria in vivo.