title: Antibody levels against GLURP R2, MSP1 block 2 hybrid and AS202.11 and the risk of malaria in children living in hyperendemic (Burkina Faso) and hypo-endemic (Ghana) areas.
abstract: BACKGROUND
  Differences in parasite transmission intensity influence the process of acquisition of host immunity to Plasmodium falciparum malaria and ultimately, the rate of malaria related morbidity and mortality. Potential vaccines being designed to complement current intervention efforts therefore need to be evaluated against different malaria endemicity backgrounds.
  
  
  METHODS
  The associations between antibody responses to the chimeric merozoite surface protein 1 block 2 hybrid (MSP1 hybrid), glutamate-rich protein region 2 (GLURP R2) and the peptide AS202.11, and the risk of malaria were assessed in children living in malaria hyperendemic (Burkina Faso, n = 354) and hypo-endemic (Ghana, n = 209) areas. Using the same reagent lots and standardized protocols for both study sites, immunoglobulin (Ig) M, IgG and IgG sub-class levels to each antigen were measured by ELISA in plasma from the children (aged 6-72 months). Associations between antibody levels and risk of malaria were assessed using Cox regression models adjusting for covariates.
  
  
  RESULTS
  There was a significant association between GLURP R2 IgG3 and reduced risk of malaria after adjusting age of children in both the Burkinabe (hazard ratio 0.82; 95 % CI 0.74-0.91, p < 0.0001) and the Ghanaian (HR 0.48; 95 % CI 0.25-0.91, p = 0.02) cohorts. MSP1 hybrid IgM was associated (HR 0.85; 95 % CI 0.73-0.98, p = 0.02) with reduced risk of malaria in Burkina Faso cohort while IgG against AS202.11 in the Ghanaian children was associated with increased risk of malaria (HR 1.29; 95 % CI 1.01-1.65, p = 0.04).
  
  
  CONCLUSIONS
  These findings support further development of GLURP R2 and MSP1 block 2 hybrid, perhaps as a fusion vaccine antigen targeting malaria blood stage that can be deployed in areas of varying transmission intensity.
authors.affiliation: Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana. badu@noguchi.ug.edu.gh.
authors.forename: Bright
authors.initials: B
authors.lastname: Adu
authors.affiliation: Polytechnic University of BoboDioulasso, Bobo-Dioulasso, Burkina Faso. Cherif.mariama@yahoo.fr.|Centre National de Recherche et de Formation sur le paludisme, Ouagadougou, Burkina Faso. Cherif.mariama@yahoo.fr.
authors.forename: Mariama K
authors.initials: MK
authors.lastname: Cherif
authors.affiliation: School of Public Health, University of Ghana, Legon, Ghana. sbosomprah@gmail.com.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bosomprah
authors.affiliation: Centre National de Recherche et de Formation sur le paludisme, Ouagadougou, Burkina Faso. a.diarra.cnrfp@fasonet.bf.
authors.forename: Amidou
authors.initials: A
authors.lastname: Diarra
authors.affiliation: Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. fareedarthur@yahoo.com.
authors.forename: Fareed K N
authors.initials: FK
authors.lastname: Arthur
authors.affiliation: Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana. EDickson@noguchi.ug.edu.gh.
authors.forename: Emmanuel K
authors.initials: EK
authors.lastname: Dickson
authors.affiliation: Department of Biochemistry, University of Lausanne, Epalinges, Switzerland. giampietro.corradin@unil.ch.
authors.forename: Giampietro
authors.initials: G
authors.lastname: Corradin
authors.affiliation: Institute of Cell, Animal and Population Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, UK. David.Cavanagh@ed.ac.uk.
authors.forename: David R
authors.initials: DR
authors.lastname: Cavanagh
authors.affiliation: Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark. mth@ssi.dk.
authors.forename: Michael
authors.initials: M
authors.lastname: Theisen
authors.affiliation: Centre National de Recherche et de Formation sur le paludisme, Ouagadougou, Burkina Faso. s.sirima.cnlp@fasonet.bf.
authors.forename: Sodiomon B
authors.initials: SB
authors.lastname: Sirima
authors.affiliation: Centre National de Recherche et de Formation sur le paludisme, Ouagadougou, Burkina Faso. issanebie.cnlp@fasonet.bf.
authors.forename: Issa
authors.initials: I
authors.lastname: Nebie
authors.affiliation: Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana. DDodoo@noguchi.ug.edu.gh.
authors.forename: Daniel
authors.initials: D
authors.lastname: Dodoo
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood*; D002050:Burkina Faso / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000276:immunology*; D020066:Merozoite Surface Protein 1 / Q000276:immunology; D010455:Peptides / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D020066:Merozoite Surface Protein 1; D010455:Peptides; D015800:Protozoan Proteins; C072492:glutamate-rich protein, Plasmodium