- An accurate new tool to measure antibodies against malaria has been developed.
- This new tool requires very small amounts of blood to perform the test.
- It can assess natural and vaccine-induced responses to malaria and other parasites.
A simple, accurate, and reproducible assay to measure antibodies against multiple Plasmodium falciparum proteins (or antigens) has been developed by a research team at the Barcelona Institute for Global Health (ISGLOBAL).
In a series of recently published articles, a team led by ISGlobal - an institution supported by "la Caixa" Foundation - reports the development and optimization of several 'quantitative suspension array' assays (qSAT) that could help assess natural and vaccine-induced responses to malaria and other parasites.
‘A promising new tool to measure antibodies against malaria using a small amount of blood has been developed.’
Antibody responses against P. falciparumparasites are critical in controlling - or even preventing- the disease. However, relatively little is known about the type and specificity of these protective antibodies, or how they work. This is further complicated by the fact that the parasite expresses more than 5000 proteins.
ISGlobal researcher Carlota Dobaņo and her group have developed new laboratory protocols to measure antibodies to multiple P. falciparum antigens in one single reaction and from small amounts of circulating blood. The qSAT used here consists in coupling small microspheres or beads to different parasite antigens and then testing if they are recognized by plasma samples of individuals exposed (or not) to malaria.
The authors first adapted the assay to detect different types and classes of antibodies
against multiple P. falciparum antigens, in a sensitive and specific manner. Second, they showed that this simple multiplex assay is highly reproducible
not only between experiments but also between operators and laboratories. Third, they identified which are the key factors that need to be optimized to reduce variability of the assay. Finally, they used this test to better characterize the antibody profile of the anti-malaria human plasma pool
provided by the WHO as reference reagent. They showed that it contains low levels of antibodies to CSP (the antigen contained in the RTS,S vaccine), suggesting that customized reference pools may be needed for studying responses to certain antigens.
These simple and reproducible multiplex protocols will allow us to analyze in detail natural and vaccine-induced antibody responses to large panels of P. falciparum antigens, and elucidate correlates of malaria protection
," explains Dobaņo. "Furthermore, the assay is highly versatile and can be adapted to study responses to antigens from other microbes or vaccines. We are currently collaborating with several groups outside the malaria
field," she adds.
- Analysis of Factors Affecting the Variability of a Quantitative Suspension Bead Array Assay Measuring Igg to Multiple Plasmodium Antigens