CANBERRA, Aug. 1 (Xinhua) -- Platelets found within blood are the human body's first line of defence against malaria, a study announced on Wednesday.
The study, published by the Menzies School of Health Research (MSHR) in Australia's Northern Territory (NT), revealed that platelets attack and kill malaria parasites in the bloodstream.
Researchers from MSHR were assisted by collaborators from Australian National University (ANU) and from Malaysia and Indonesia.
They found that the platelets attack by binding themselves to each of the malaria parasite species which are lethal to humans.
"These are important findings and are the first direct evidence of protection by platelets in any human infectious disease," Steven Kho, a Menzied PhD student who was the lead author of the study, said in a media release on Wednesday.
"The platelets bind to the human red cells, containing the malaria parasites, and kill the parasites by releasing into the red cell a toxic platelet peptide called PF4. PF4-based peptides may be potential candidates for malaria treatment in the future.
"We found that platelets may kill around 20 percent of circulating Plasmodium parasites in clinical malaria, and in Plasmodium vivax this may be as high as 60 percent."
The study involved 376 people from Papua New Guinea, Indonesia and Malaysia.
Nick Anstey, a senior principal research fellow at MSHR, said that the human aspect of the study was crucial.
"Previous studies in laboratory mice infected with malaria parasites have shown conflicting results, but the findings in human malaria are now clear -- platelets kill parasites. Studies involving people with malaria are often difficult to do and they are expensive, but this study shows why they are essential," he said.