Analysis of antibody profiles in symptomatic malaria in three sentinel sites of Ivory Coast by using multiplex, fluorescent, magnetic, bead-based serological assay (MAGPIX™)

Abstract

BackgroundAdvances in malaria control have reduced the burden of disease resulting from exposure to parasite infections. The consequences on naturally acquired immunity are unclear. A magnetic bead-based immunoassay (MBA) to assess antibody levels in populations living in endemic areas was previously evaluated. In this study, the effect of clinical attacks on immunity was analysed in three sentinel sites of Ivory Coast.MethodsRecombinant proteins or peptides derived from liver or blood stage antigens of Plasmodiumfalciparum (CSP, LSA141, LSA3, SALSA, PF13-DBL1α1, GLURP, AMA1, MSP1p19, MSP4p20), the CSP of Plasmodium malariae and the salivary glands antigen of Anopheles gambiae (gSG6) were covalently linked to a colour-coded microsphere (Luminex™ beads) for the multiplex assay. ELISA was used for whole parasite extract antigen. Blood samples (n = 94) of patients consulting for symptomatic malaria attacks and living in three different malaria endemic settings (rural and periurban) were analysed.ResultsHighly variable seroprevalence of antibody responses against parasite antigens was found ranging from 3 (gSG6) to 97 % (MSP4p20). A marked prevalence and significantly higher level of antibodies was found in patients from the rural site (Korhogo), those harbouring the lowest level of parasitaemia. The use of whole schizont extract could not discriminate immunity level, contrary to parasite-derived recombinant proteins or peptides. Prevalence of responders to LSA141 and levels of antibodies to PF13 were significantly different between the three settings. Moreover, the post-treatment clearance of parasites was clearly associated with a significantly higher level of antibody response for almost 50 % of the parasite antigens tested.ConclusionThe multiplex MBA-Magpix technology assay provides an accurate high throughput monitoring of parasite-specific antibodies during symptomatic malaria. The levels of antibody responses may provide a risk criterion with respect to the degree of parasitic infection. Additionally, they can be used as an indicator in the implementation of malaria prevention and local control strategies.

Serological markers to measure recent changes in malaria at population level in Cambodia

“…Helb et al [13] and Yman et al [12] estimated recent P. falciparum exposure at individual (longitudinal data) and population level (cross-sectional data). Studies based on longitudinal data mainly use approaches such as linear regression models [13, 20], generalized linear models (GLM) [64], or Ab-intensity models [12] to analyse Ab profiles.…”

Practical example of multiple antibody screening for evaluation of malaria control strategies

“…In the study of patients from Côte d'Ivoire, parasite invasion strongly stimulates immune responses and antibody responses may be higher in more exposed persons who, therefore, have a higher degree of acquired immunity [37]. Cross-sectional analysis of randomly recruited symptomatic and well-documented cases from sentinel sites, showed that a multi-target measure of antibody responses could constitute a surrogate of actual immune status [25]. Here, IgG responses to SE, MSP1 and LSA1 41 in sentinel sites were compared with results from asymptomatic recruitment (AR) in Abobo and severe malaria cases (SM) from the CHU of Abidjan (Table 1).…”

“…Individual informed written consent was obtained from participants/parents/guardians. All clinical cases were treated and followed-up according to the standard national procedure as described [25,26]. The study from Senegal was done in the endemic villages of Dielmo and Ndiop, where a long-term longitudinal survey designed to study acquisition and maintenance of natural immunity has been carried out over 20 years [4,6,30].…”

“…In this report, a practical example is provided as a snapshot cross-sectional picture using samples from symptomatic and asymptomatic cohorts in the Côte d'Ivoire and Senegal. A large panel of antigens were initially explored using the multiplex Luminex assay [25][26][27], here analysis was focused on 3 main antigen targets: (i) a preerythrocytic antigen LSA1 41 ; (ii) a merozoite antigen MSP1p19, and (iii) a whole schizont extract (SE: measured by standard ELISA) from a local strain adapted to in vitro culture [28], as a reference antigen for overall antibody response against P. falciparum. In the cohort from Senegal, antibody responses to six additional antigens are given with regards to the sero-catalytic models.…”

Development and in-use evaluation of a novel Luminex MicroPlex microsphere-based (TRIOL) assay for simultaneous identification ofMycobacterium tuberculosisand detection of first-line and second-line anti-tuberculous drug resistance in China

“…21. Moreover, assays for evaluation of the serological antibody and/or cytokine/chemokine response to infections such as leptospirosis,22 rotavirus and flavivirus infections,23 24 malaria,25 toxoplasmosis26 and cryptosporidiosis27 have also been reported.…”