Source: 科学与发展网络 (SciDev.Net)
9 December 2008 | EN | 中文
A simple test that can distinguish cerebral malaria from less dangerous forms of the disease could help focus limited resources towards treating patients with this form, say researchers.
The researchers, at the McLaughlin-Rotman Centre for Global Health, Canada, found that the levels of two angiopoietins — proteins that regulate the activation of blood vessels — Angiopoietin-1 and Angiopoietin-2 — are abnormal in cases of cerebral malaria.
"In healthy children, the normal levels would be high for Angiopoietin-1 and low for Angiopoietin-2. There is a marked difference in cerebral malaria with low levels of Angiopoietin-1 and high levels of Angiopoietin-2, which distinguishes cerebral malaria from uncomplicated malaria," Conrad W. Liles, one of the lead researchers and vice-chair of medicine at the University of Toronto, told SciDev.Net.
The team, which collaborated with researchers from Thailand and Uganda, found that the accuracy of the test in predicting patients with cerebral malaria was high — 80 per cent in African children and 100 per cent in Thai adults.
According to Liles, the blood test for angiopoietin levels is easy to perform and the team is currently developing a kit that can be used in the field.
"This test will enable health workers to accurately identify kids to hospitalise and treat," he says.
Two to five per cent of children with malaria develop cerebral malaria and around 800,000 African children die every year from the disease — which damages the blood vessels of the brain.
Liles is also hopeful that these results can be developed into a novel treatment for cerebral malaria where, instead of targeting the malarial parasite, the damage to the host's blood vessels is prevented or treated.
The research team have also found a way of diagnosing placental malaria — until now a 'hidden' disease that manifests few symptoms in the expectant mother, but produces severe complications for the unborn child such as spontaneous abortion and low birth weight.
Their tests on pregnant women in Kenya revealed that levels of a biological indicator called C5a are elevated in those that have placental malaria compared with healthy subjects.
Both research results were reported at the annual meeting of the American Society of Tropical Medicine and Hygiene in New Orleans, United States, this week (7–11 December 2008).
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