Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Malaria Journal 410 Malaria Plasmodium falciparum ELISA IgG Surface antigens MSP1p19 PfEMP1-PF13 Multiplex MAGPIX Senegal Ndiop SENEGAL 2014 fdi:010062657 ENG Malaria Journal 1475-2875 ISI:000344122900001 10.1186/1475-2875-13-410 https://www.documentation.ird.fr/hor/fdi:010062657 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-02/010062657.pdf 13 Horizon (IRD) Background: Numerous Plasmodium falciparum antigens elicit humoral responses in humans living in endemic areas. Use of multiplex assays is a convenient approach to monitor the antibody response against multiple antigens, but to integrate multiplex assay-derived data with datasets, generated previously using ELISA, comparative studies are needed. This work compares antibody responses to two P. falciparum antigens monitored using both technologies. Methods: The IgG response against the merozoite surface protein-1 PfMSP1p19 and the PF13-DBL1 alpha 1 domain of the P. falciparum Erythrocyte Membrane Protein1, expressed by the rosette-forming parasite 3D7/PF13 (PF13), was investigated using ELISA and a MAGPIX (R)-Luminex duplex assay. Archived plasma samples collected before the rainy season from 217 villagers living in Ndiop, a Senegalese meso-endemic setting, were studied. ROC analysis was used to define the optimal antibody measure readout. Association of antibody levels with protection against clinical malaria was analysed using Poisson regression in a retrospective study from active case detection records performed during the 5.5-month transmission season that followed blood sampling. Results: There was a strong positive correlation (P <10(-3)) between ELISA and MAGPIX (R)-Luminex-MFI (median fluorescence intensity) values for antibody to PfMSP1p19 (rho = 0.78) and PF13-DBL1a1 (rho = 0.89), with a similar degree of concordance in all age groups. Antibody levels to both antigens were high but displayed a different age-associated pattern. Independent age-adjusted Poisson regression analysis showed a significant association with protection only for IgG responses to MSP1p19 (P <0.01 RR = 0.71 [0.53-0.93]) measured by ELISA. Conclusion: The individual ELISA and duplex-MAGPIX assays provide a concordant evaluation of age-associated antibody responses to MSP1p19 and PF13-DBL1a1, irrespective of the formulation of antibody levels (values, ratios or ROC-adjusted figures) but do diverge with regard to the association of antibody levels with clinical protection in age-adjusted models. This may reflect incomplete overlap of the epitopes presented in the two formats. Further development for multiplex assessment of antibody responses to a larger panel of antigens with the robust and cost effective MAGPIX (R)-Luminex technology is warranted. 052 UR198 Sénégal