TY - JOUR

T1 - Detection and quantification of Plasmodium falciparum in human blood by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

T2 - a proof of concept study

AU - Stauning, Marius Ahm

AU - Jensen, Christian Salgård

AU - Staalsøe, Trine

AU - Kurtzhals, Jørgen A L

N1 - © 2023. BioMed Central Ltd., part of Springer Nature.

PY - 2023

Y1 - 2023

N2 - BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has revolutionized identification of bacteria and is becoming available in an increasing number of laboratories in malaria-endemic countries. The purpose of this proof-of-concept study was to explore the potential of MALDI-TOF as a diagnostic tool for direct detection and quantification of Plasmodium falciparum in human blood.METHODS: Three different P. falciparum strains (3D7, HB3 and IT4) were cultured and synchronized following standard protocols. Ring-stages were diluted in fresh blood group 0 blood drawn in EDTA from healthy subjects to mimic clinical samples. Samples were treated with saponin and washed in PBS to concentrate protein material. Samples were analysed using a Microflex LT MALDI-TOF and resulting mass spectra were compared using FlexAnalysis software.RESULTS: More than 10 peaks specific for P. falciparum were identified. The identified peaks were consistent among the three genetically unrelated strains. Identification was possible in clinically relevant concentrations of 0.1% infected red blood cells, and a close relationship between peak intensity and the percentage of infected red blood cells was seen.CONCLUSION: The findings indicate that the method has the potential to detect and quantify P. falciparum at clinically relevant infection intensities and provides proof-of-concept for MALDI-TOF-based diagnosis of human malaria. Further research is needed to include other Plasmodium spp., wildtype parasite isolates and to increase sensitivity. MALDI-TOF may be a useful tool for mass-screening purposes and for diagnosis of malaria in settings where it is readily available.

AB - BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has revolutionized identification of bacteria and is becoming available in an increasing number of laboratories in malaria-endemic countries. The purpose of this proof-of-concept study was to explore the potential of MALDI-TOF as a diagnostic tool for direct detection and quantification of Plasmodium falciparum in human blood.METHODS: Three different P. falciparum strains (3D7, HB3 and IT4) were cultured and synchronized following standard protocols. Ring-stages were diluted in fresh blood group 0 blood drawn in EDTA from healthy subjects to mimic clinical samples. Samples were treated with saponin and washed in PBS to concentrate protein material. Samples were analysed using a Microflex LT MALDI-TOF and resulting mass spectra were compared using FlexAnalysis software.RESULTS: More than 10 peaks specific for P. falciparum were identified. The identified peaks were consistent among the three genetically unrelated strains. Identification was possible in clinically relevant concentrations of 0.1% infected red blood cells, and a close relationship between peak intensity and the percentage of infected red blood cells was seen.CONCLUSION: The findings indicate that the method has the potential to detect and quantify P. falciparum at clinically relevant infection intensities and provides proof-of-concept for MALDI-TOF-based diagnosis of human malaria. Further research is needed to include other Plasmodium spp., wildtype parasite isolates and to increase sensitivity. MALDI-TOF may be a useful tool for mass-screening purposes and for diagnosis of malaria in settings where it is readily available.

U2 - 10.1186/s12936-023-04719-8

DO - 10.1186/s12936-023-04719-8

M3 - Journal article

C2 - 37752504

VL - 22

JO - Malaria Journal

JF - Malaria Journal

SN - 1475-2875

M1 - 285

ER -