title: Development and evaluation of a multiplex screening assay for Plasmodium falciparum exposure.
abstract: Transfusion transmitted malaria (TTM) in non-endemic countries is reduced by questioning blood donors and screening of donated blood. Conventional screening is performed by Indirect Fluorescence Antibody Test (IFAT). This method is manual and difficult to standardize. Here we study the diagnostic performance of a multiplex assay for detection of antibodies against Plasmodium falciparum in donor blood using IFAT as a comparator. A multiplex assay (MPA) containing the antigens GLURP-R0, GLURP-R2, MSP3, MSP1 hybrid and AMA1 was constructed using xMAP® technology. A discrimination index for exposure to P. falciparum malaria was calculated by comparing travelers with clinical malaria (n=52) and non-exposed blood donors (n=119). The index was evaluated on blood donors with suspected malaria exposure (n=249) and compared to the diagnostic performance of IFAT. At a specificity of 95.8 %, the MPA discrimination index exhibited a diagnostic sensitivity of 90.4 % in travelers hospitalized with malaria. Percent agreement with IFAT was 92.3 %. Screening plasma from blood donors with suspected malaria exposure, we found 4.8 % to be positive by IFAT and 5.2 % by MPA with an agreement of 93.2 %. The calculated index from the MPA exhibits similar diagnostic performance as IFAT for detection of P. falciparum malaria. Combining the antibody response against multiple antigens in a discrimination index increased the sensitivity of the MPA and reduced the readout to a single value.
authors: Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Copenhagen, Denmark.
authors: Micha Phill Grønholm
authors: MP
authors: Jepsen
authors: Dennis
authors: D
authors: Röser
authors: Michael
authors: M
authors: Christiansen
authors: Severin
authors: S
authors: Olesen Larsen
authors: David R
authors: DR
authors: Cavanagh
authors: Kelwalin
authors: K
authors: Dhanasarnsombut
authors: Ib
authors: I
authors: Bygbjerg
authors: Daniel
authors: D
authors: Dodoo
authors: Edmond J
authors: EJ
authors: Remarque
authors: Morten
authors: M
authors: Dziegiel
authors: Søren
authors: S
authors: Jepsen
authors: Benjamin
authors: B
authors: Mordmüller
authors: Michael
authors: M
authors: Theisen
mesh_terms: D000953:Antigens, Protozoan / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D008403:Mass Screening / Q000379:methods; D020066:Merozoite Surface Protein 1 / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology; D012372:ROC Curve; D015203:Reproducibility of Results; D014195:Travel
chemical_list: D000953:Antigens, Protozoan; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C089133:merozoite surface protein 3, Plasmodium; C072492:glutamate-rich protein, Plasmodium