RDT test: antigens

---

Navigation
Main Malaria Index
>RDT main page
>>This page: The RDT antigens

---

RDT Test antigens: review of advantages and disadvantages

---

Overview Several forms of malarial protein may be used to identify malaria based on their expression or structure. For example, the HRP2 protein used to identify Plasmodium falciparum has specific functions for that parasite and HRP2 is not found in other malarial species (or humans) so has high specificity for the diagnosis of P.falciparum. Other proteins are outwardly less specific, with the major examples forming part of metabolic pathways active in both humans and malaria (lactate dehydrogenase and aldolase). However, for these proteins there are clear structural differences between human and parasite forms of these proteins, and in some cases also between the different malarial species. These different structural featues give rise to antigenic epitopses that can be used to identify malarial parasites as a group (pan-malarial antigens) or distinguish different malarial species (species specific antigens). Malaria-species-specific antigens These are expressed only by specific malaria species; and can therefore be used to identify these species. Two malaria-specific antigens are widely employed in RDT assays. These are: (1) Histidine-rich protein 2 (HRP2): An antigen that is specific for P.falciparum - Click for details of HRP2 (2) Detects lactate dehydrogenase epitopes that are specific for either P.falciparum or P.vivax Click for details of PfLDH or PvLDH Malaria pan-specific antigens used in RDT tests Protein antigens found in all malaria species (but not humans) are called "pan specific". This means they can be used to identify the presence of malaria, although without any species specificity. There are two protein main antigens that are used for this purpose. These may: (1) Lactate dehydrogenase epitopes that are present on all malaria species (pan-malarial LDH) (2) Aldolase epitopes found in all malarial species but not humans (pan-malarila aldolase) Click for details of pan-malarial LDH and aldolase