title: A new ELISA kit which uses a combination of Plasmodium falciparum extract and recombinant Plasmodium vivax antigens as an alternative to IFAT for detection of malaria antibodies.
abstract: BACKGROUND
  The methods most commonly used to measure malarial antibody titres are the Indirect Fluorescence Antibody Test (IFAT), regarded as the gold standard, and the Enzyme-Linked ImmunoSorbent Assay (ELISA). The objective here was to assess the diagnostic performance, i.e. the sensitivity and specificity, of a new malaria antibody ELISA kit in comparison to IFAT. This new ELISA kit, the ELISA malaria antibody test (DiaMed), uses a combination of crude soluble Plasmodium falciparum extract and recombinant Plasmodium vivax antigens.
  
  
  METHODS
  Two groups were used: 95 samples from malaria patients to assess the clinical sensitivity and 2,152 samples from blood donors, who had not been exposed to malaria, to assess the clinical specificity.
  
  
  RESULTS
  The DiaMed ELISA test kit had a clinical sensitivity of 84.2% and a clinical specificity of 99.6% as compared with 70.5% and 99.6% respectively, using the IFAT method. The ELISA method was more sensitive than the IFAT method for P. vivax infections (75% vs. 25%). However, in 923 malaria risk donors the analytical sensitivity of the ELISA test was 40% and its specificity 98.3%, performances impaired by large numbers of equivocal results non-concordant between ELISA and IFAT. When the overall analytical performances of ELISA was compared to IFAT, the ELISA efficiency J index was 0.84 versus 0.71 for IFAT. Overall analytical sensitivity was 93.1% and the analytical specificity 96.7%. Overall agreement between the two methods reached 0.97 with a reliability k index of 0.64.
  
  
  CONCLUSIONS
  The DiaMed ELISA test kit shows a good correlation with IFAT for analytical and clinical parameters. It may be an interesting method to replace the IFAT especially in blood banks, but further extensive investigations are needed to examine the analytical performance of the assay, especially in a blood bank setting.
authors.affiliation: Institut de Parasitologie et de Pathologie Tropicale, 3 rue Koeberlé, 67000 Strasbourg cedex, France. cecile.doderer@medecine.u-strasbg.fr <cecile.doderer@medecine.u-strasbg.fr>
authors.forename: Cecile
authors.initials: C
authors.lastname: Doderer
authors.forename: Aurelie
authors.initials: A
authors.lastname: Heschung
authors.forename: Phillippe
authors.initials: P
authors.lastname: Guntz
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Cazenave
authors.forename: Yves
authors.initials: Y
authors.lastname: Hansmann
authors.forename: Alexandre
authors.initials: A
authors.lastname: Senegas
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Pfaff
authors.forename: Tamer
authors.initials: T
authors.lastname: Abdelrahman
authors.forename: Ermanno
authors.initials: E
authors.lastname: Candolfi
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000302:isolation & purification; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008288:Malaria / Q000175:diagnosis*; D016780:Malaria, Vivax / Q000175:diagnosis; D010961:Plasmodium / Q000276:immunology*; D010963:Plasmodium falciparum / Q000276:immunology; D010966:Plasmodium vivax / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D011994:Recombinant Proteins