| Use of pan-malarial antigen RDTs in diagnosis
Background
Plasmodium aldolase (Paldolase) and plasmodium lactate dehydrogenase (PLDH) are part of glycolysis pathways in all malaria species. Since malaria parasites have specific forms, antibodies do not cross-react with human aldolase or LDH. Antibodies to these proteins may potentially recognise all species of malaria and are known as “pan-malaria specific antibodies”.
- Plasmodium lactate dehydrogenase (PpanLDH)
- Plasmodium aldolase (Paldolase)
Outside of Africa, the most frequently used form of malaria RDT combines a species-specific with a pan-species antibody e.g. HRP2/LDH or HRP2/aldolase.
Use in malaria testing
The potential of pan-malarial antibody tests to detect any species of malaria makes the proteins attractive in the general detection of any forma of malaria. ‘’’However’’’ their performance is not ideal since although both offer good sensitivity for the recognition of ‘’P.falciparum’’ and ‘’P.vivax’’ they are less effective in the detection of other species (particularly at lower parasite concentrations.) so they provide limited confidence when used alone.
Their use in combination tests is helpful when:
(1) A malarial species may be present that would not be detected by the species-specific antibody. The pan-malarial antibody may detect that species.
(2) If the species-specific antibody gives a false negative result (for example, gene deletion or prozone effect) then the pan-malarial antibody may still allow the infection to be detected.
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