title: Plasmodium berghei bio-burden correlates with parasite lactate dehydrogenase: application to murine Plasmodium diagnostics.
abstract: BACKGROUND
  The spectrum of techniques to detect malaria parasites in whole blood is limited to measuring parasites in circulation. One approach that is currently used to enumerate total parasite bio-burden involves the use of bio-luminescent parasites. As an alternative approach, this study describes the use of a commercial ELISA human parasite lactate dehydrogenase (pLDH) detection kit to estimate total parasite bio-burden in murine malaria models.
  
  
  METHODS
  The cross reactivity of pLDH in a commercial human malaria pLDH diagnostic kit was established in different components of blood for different murine malaria models. The use of pLDH as a measure of parasite bio-burden was evaluated by examining pLDH in relation to peripheral blood parasitaemia as determined by microscopy and calculating total parasite bio-burden using a bio-luminescent Plasmodium berghei ANKA luciferase parasite.
  
  
  RESULTS
  The pLDH antigen was detected in all four murine Plasmodium species and in all components of Plasmodium-infected blood. A significant correlation (r = 0.6922, P value <0.0001) was observed between total parasite bio-burden, measured as log average radiance, and concentration of pLDH units.
  
  
  CONCLUSIONS
  This high throughput assay is a suitable measure of total parasite bio-burden in murine malaria infections. Unlike existing methods, it permits the estimation of both circulating and sequestered parasites, allowing a more accurate assessment of parasite bio-burden.
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia. s.de@griffith.edu.au.
authors.forename: Sai Lata
authors.initials: SL
authors.lastname: De
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia. d.stanisic@griffith.edu.au.
authors.forename: Danielle I
authors.initials: DI
authors.lastname: Stanisic
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia. fabian.rivera@qimrberghofer.edu.au.
authors.forename: Fabian
authors.initials: F
authors.lastname: Rivera
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia. m.batzloff@griffith.edu.au.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Batzloff
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia. Christian.Engwerda@qimrberghofer.edu.au.
authors.forename: Christian
authors.initials: C
authors.lastname: Engwerda
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia. michael.good@griffith.edu.au.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Good
mesh_terms: D000818:Animals; D005260:Female; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008288:Malaria / Q000097:blood* / Q000175:diagnosis*; D051379:Mice; D008807:Mice, Inbred BALB C; D018512:Parasitemia / Q000097:blood / Q000175:diagnosis; D010962:Plasmodium berghei / Q000201:enzymology*; D015800:Protozoan Proteins / Q000097:blood
chemical_list: D015800:Protozoan Proteins; D007770:L-Lactate Dehydrogenase