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Mayor A, Dobaño C, Nhabomba A, Guinovart C, Jiménez A, Manaca MN, Aguilar R, Barbosa A, Rodríguez MH, Cisteró P, Quimice LM, Menéndez C, Aponte JJ, Ordi J, Chitnis CE, Alonso PL. IgM and IgG against Plasmodium falciparum lysate as surrogates of malaria exposure and protection during pregnancy. Malar J 2018; 17:182. [PMID: 29743114 PMCID: PMC5944166 DOI: 10.1186/s12936-018-2331-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/24/2018] [Indexed: 11/10/2022] Open
Abstract
Background Difficulties to disentangle the protective versus exposure role of anti-malarial antibodies hamper the identification of clinically-relevant immune targets. Here, factors affecting maternal IgG and IgMs against Plasmodium falciparum antigens, as well as their relationship with parasite infection and clinical outcomes, were assessed in mothers and their children. Antibody responses among 207 Mozambican pregnant women at delivery against MSP119, EBA175, AMA1, DBLα and parasite lysate (3D7, R29 and E8B parasite lines), as well as the surface of infected erythrocytes, were assessed by enzyme-linked immunosorbent assay and flow cytometry. The relationship between antibody levels, maternal infection and clinical outcomes was assessed by multivariate regression analysis. Results Placental infection was associated with an increase in maternal levels of IgGs and IgMs against a broad range of parasite antigens. The multivariate analysis including IgGs and IgMs showed that the newborn weight increased with increasing IgG levels against a parasite lysate, whereas the opposite association was found with IgMs. IgGs are markers of protection against poor pregnancy outcomes and IgMs of parasite exposure. Conclusions Adjusting the analysis for the simultaneous effect of IgMs and IgGs can contribute to account for heterogeneous exposure to P. falciparum when assessing immune responses effective against malaria in pregnancy. Electronic supplementary material The online version of this article (10.1186/s12936-018-2331-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alfredo Mayor
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Augusto Nhabomba
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Caterina Guinovart
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Alfons Jiménez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Ruth Aguilar
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Arnoldo Barbosa
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Mauricio H Rodríguez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Pau Cisteró
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain
| | - Lazaro M Quimice
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Clara Menéndez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - John J Aponte
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Jaume Ordi
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain
| | - Chetan E Chitnis
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Pedro L Alonso
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
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Abstract
One hundred and twenty-five million women in malaria-endemic areas become pregnant each year (see Dellicour et al. PLoS Med7: e1000221 [2010]) and require protection from infection to avoid disease and death for themselves and their offspring. Chloroquine prophylaxis was once a safe approach to prevention but has been abandoned because of drug-resistant parasites, and intermittent presumptive treatment with sulfadoxine-pyrimethamine, which is currently used to protect pregnant women throughout Africa, is rapidly losing its benefits for the same reason. No other drugs have yet been shown to be safe, tolerable, and effective as prevention for pregnant women, although monthly dihydroartemisinin-piperaquine has shown promise for reducing poor pregnancy outcomes. Insecticide-treated nets provide some benefits, such as reducing placental malaria and low birth weight. However, this leaves a heavy burden of maternal, fetal, and infant morbidity and mortality that could be avoided. Women naturally acquire resistance to Plasmodium falciparum over successive pregnancies as they acquire antibodies against parasitized red cells that bind chondroitin sulfate A in the placenta, suggesting that a vaccine is feasible. Pregnant women are an important reservoir of parasites in the community, and women of reproductive age must be included in any elimination effort, but several features of malaria during pregnancy will require special consideration during the implementation of elimination programs.
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Affiliation(s)
- Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD 20892
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD 20892
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3
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Stephens JK, Kyei-Baafour E, Dickson EK, Ofori JK, Ofori MF, Wilson ML, Quakyi IA, Akanmori BD. Effect of IPTp on Plasmodium falciparum antibody levels among pregnant women and their babies in a sub-urban coastal area in Ghana. Malar J 2017; 16:224. [PMID: 28549426 PMCID: PMC5446726 DOI: 10.1186/s12936-017-1857-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/12/2017] [Indexed: 12/31/2022] Open
Abstract
Background Women exposed to Plasmodium infection develop antibodies and become semi-immune. This immunity is suppressed during pregnancy making both the pregnant woman and the foetus vulnerable to the adverse effects of malaria, particularly by Plasmodium falciparum. Intermittent preventive treatment of malaria in pregnancy (IPTp) with Sulfadoxine–pyrimethamine (SP) tablets is one of the current interventions to mitigate the effects of malaria on both the pregnant woman and the unborn child. The extent to which IPTp may interfere with the acquisition of protective immunity against pregnancy-associated malaria (PAM) is undefined in Ghana. Methods Three-hundred-and-twenty pregnant women were randomly enrolled at the antenatal clinic (ANC) in Madina, Accra. Venous blood samples were obtained at first ANC registration and at 4-week intervals (post-IPTp administration). Placental and cord blood samples were obtained at delivery and the infants were followed monthly for 6 months after birth. Anti-IgG and IgM antibodies against a crude antigen preparation and the glutamate-rich protein (GLURP) of P. falciparum were quantified by the enzyme-linked immunosorbent assay (ELISA). Results There was a general decline in the trend of mean concentrations of all the antibodies from enrolment to delivery. The levels of antibodies in cord blood and placenta were well correlated. Children did not show clinical signs of malaria at 6 months after birth. Conclusions IgG against both crude antigen and GLURP were present in placenta and cord blood and it is therefore concluded that there is a trend of declining antibody from enrolment to delivery and IPTp-SP may have reduced malaria exposure, however, this does not impact on the transfer of antibodies to the foetus in utero. The levels of maternal and cord blood antibodies at delivery showed no adverse implications on malaria among the children at 6 months. However, the quantum and quality of the antibody transferred needs further investigation to ensure that the infants are protected from severe episodes of malaria.
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Affiliation(s)
- Judith K Stephens
- Biological, Environmental and Occupational and Health Sciences Department, School of Public Health, College of Health Sciences, University of Ghana, P. O. Box LG 13, Legon, Accra, Ghana.
| | - Eric Kyei-Baafour
- Immunology Department Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG 581, Legon, Accra, Ghana
| | - Emmanuel K Dickson
- Immunology Department Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG 581, Legon, Accra, Ghana
| | - Jones K Ofori
- Biological, Environmental and Occupational and Health Sciences Department, School of Public Health, College of Health Sciences, University of Ghana, P. O. Box LG 13, Legon, Accra, Ghana
| | - Michael F Ofori
- Immunology Department Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG 581, Legon, Accra, Ghana
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, The University of Michigan, 109 Observatory Street, Ann Arbor, MI, 48109-2029, USA
| | - Isabella A Quakyi
- Biological, Environmental and Occupational and Health Sciences Department, School of Public Health, College of Health Sciences, University of Ghana, P. O. Box LG 13, Legon, Accra, Ghana
| | - Bartholomew D Akanmori
- Immunology Department Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P. O. Box LG 581, Legon, Accra, Ghana.,Vaccine Research and Development, Immunization and Vaccines Development Cluster, Office of the Regional Director, WHO Regional Office for Africa, P. O. Box 06, Djoue, Brazzaville, Congo
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4
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Gueneuc A, Deloron P, Bertin GI. Usefulness of a biomarker to identify placental dysfunction in the context of malaria. Malar J 2017; 16:11. [PMID: 28049536 PMCID: PMC5209802 DOI: 10.1186/s12936-016-1664-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/21/2016] [Indexed: 11/25/2022] Open
Abstract
In most tropical areas, pregnant women are at increased risk of malaria, as a consequence of the massive sequestration of parasitized red blood cells in the placenta. The placenta plays a key role in embryonic and fetal development as well as in maternal-fetal exchanges, and pregnancy-associated malaria may alter selected placenta functions that lead to stillbirth and low birth weight. Although there are several tools (blood smear examination, RDT, PCR) to diagnose malaria infection during pregnancy, there is currently no test to assess placenta dysfunction in the framework of pregnancy-associated malaria. Pregnancy-associated malaria shares many features with preeclampsia, an extensively studied disease. Various biomarkers associated with placental dysfunction have been identified as associated with preeclampsia. Several of these are inflammatory markers that lack of specificity. A few seem more specific of placenta dysfunction, including s-endoglin and sFlt1, increased in the peripheral blood during preeclampsia. The predictive value of these biomarkers should be studied in the context of pregnancy-associated malaria to evaluate their usefulness in identifying placental dysfunction during malaria. These biomarkers should be considered to improve the diagnosis of placental dysfunction during malaria and pregnant women monitoring.
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Affiliation(s)
- Alexandra Gueneuc
- Institute of Research for Development (IRD), UMR216-MERIT, Paris, France.,ComUE Sorbonne Paris Cité, Paris, France.,Obstetrics and Fetal Medicine Department, Necker-Enfants-Malades Hospital, Paris, France
| | - Philippe Deloron
- Institute of Research for Development (IRD), UMR216-MERIT, Paris, France.,ComUE Sorbonne Paris Cité, Paris, France.,DHU Risks in Pregnancy, Paris, France
| | - Gwladys I Bertin
- Institute of Research for Development (IRD), UMR216-MERIT, Paris, France. .,ComUE Sorbonne Paris Cité, Paris, France. .,DHU Risks in Pregnancy, Paris, France.
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Fried M, Duffy PE. Designing a VAR2CSA-based vaccine to prevent placental malaria. Vaccine 2015; 33:7483-8. [PMID: 26469717 PMCID: PMC5077158 DOI: 10.1016/j.vaccine.2015.10.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 09/23/2015] [Accepted: 10/02/2015] [Indexed: 11/29/2022]
Abstract
Placental malaria (PM) due to Plasmodium falciparum is a major cause of maternal, fetal and infant mortality, but the mechanisms of pathogenesis and protective immunity are relatively well-understood for this condition, providing a path for vaccine development. P. falciparum parasites bind to chondroitin sulfate A (CSA) to sequester in the placenta, and women become resistant over 1–2 pregnancies as they acquire antibodies that block adhesion to CSA. The protein VAR2CSA, a member of the PfEMP1 variant surface antigen family, mediates parasite adhesion to CSA, and is the leading target for a vaccine to prevent PM. Obstacles to PM vaccine development include the large size (~350 kD), high cysteine content, and sequence variation of VAR2CSA. A number of approaches have been taken to identify the combination of VAR2CSA domains and alleles that can induce broadly active antibodies that block adhesion of heterologous parasite isolates to CSA. This review summarizes these approaches, which have examined VAR2CSA fragments for binding activity, antigenicity with naturally acquired antibodies, and immunogenicity in animals for inducing anti-adhesion or surface-reactive antibodies. Two products are expected to enter human clinical studies in the near future based on N-terminal VAR2CSA fragments that have high binding affinity for CSA, and additional proteins preferentially expressed by placental parasites are also being examined for their potential contribution to a PM vaccine.
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Affiliation(s)
- Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, 5640 Fishers Lane, TWB1/Room 1111, Rockville, MD, USA.
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, 5640 Fishers Lane, TWB1/Room 1111, Rockville, MD, USA.
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Ataíde R, Mayor A, Rogerson SJ. Malaria, primigravidae, and antibodies: knowledge gained and future perspectives. Trends Parasitol 2013; 30:85-94. [PMID: 24388420 DOI: 10.1016/j.pt.2013.12.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/08/2013] [Accepted: 12/08/2013] [Indexed: 10/25/2022]
Abstract
Pregnant women have an increased risk of malaria infection, independent of previously acquired immunity. Women in their first pregnancy and children under the age of five are the primary victims of malaria worldwide. Pregnant women develop antibodies against placenta-adhesive parasites in a parity-dependent manner. Various efforts to understand the targets, quality, and quantity of this antibody response could aid the design of an effective vaccine against placental malaria. This review focuses on the research that has led to the current understanding of the antibody response that primigravidae (PG) acquire to Plasmodium falciparum malaria and draws from this knowledge to suggest serology and PG as sentinels for malaria transmission.
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Affiliation(s)
- Ricardo Ataíde
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia.
| | - Alfredo Mayor
- Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde da Manhiça (CISM), Manhiça, Mozambique
| | - Stephen J Rogerson
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia
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7
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Bertin GI, Lavstsen T, Guillonneau F, Doritchamou J, Wang CW, Jespersen JS, Ezimegnon S, Fievet N, Alao MJ, Lalya F, Massougbodji A, Ndam NT, Theander TG, Deloron P. Expression of the domain cassette 8 Plasmodium falciparum erythrocyte membrane protein 1 is associated with cerebral malaria in Benin. PLoS One 2013; 8:e68368. [PMID: 23922654 PMCID: PMC3726661 DOI: 10.1371/journal.pone.0068368] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 05/29/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1) is a highly polymorphic adherence receptor expressed on the surface of infected erythrocytes. Based on sequence homology PfEMP-1 variants have been grouped into three major groups A-C, the highly conserved VAR2CSA variants, and semi-conserved types defined by tandem runs of specific domains ("domain cassettes" (DC)). The PfEMP-1 type expressed determines the adherence phenotype, and is associated with clinical outcome of infection. METHODS Parasite isolates from Beninese children or women presenting with, respectively, CM or PAM were collected along with samples from patients with uncomplicated malaria (UM). We assessed the transcript level of var genes by RT-qPCR and the expression of PfEMP-1 proteins by LC-MS/MS. RESULTS Var genes encoding DC8 and Group A PfEMP-1 were transcribed more often and at higher levels in cerebral malaria vs. uncomplicated malaria patients. LC-MS/MS identified peptides from group A, DC8 PfEMP-1 more frequently in cerebral malaria than in uncomplicated malaria and pregnancy-associated malaria samples. CONCLUSION This is the first study to show association between PfEMP-1 subtype and disease outcome by direct analysis of parasites proteome. The results corroborate that group A and specifically the PfEMP-1 types DC8 are universally associated with cerebral malaria. This is a crucial observation for promoting studies on malaria pathogenesis.
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MESH Headings
- Adolescent
- Adult
- Benin
- Child
- Child, Preschool
- Chromatography, Liquid
- Female
- Gene Expression Regulation
- Genes, Protozoan
- Humans
- Malaria, Cerebral/genetics
- Malaria, Cerebral/parasitology
- Mass Spectrometry
- Plasmodium falciparum/genetics
- Plasmodium falciparum/physiology
- Pregnancy
- Pregnancy Complications, Parasitic/genetics
- Pregnancy Complications, Parasitic/parasitology
- Protein Structure, Tertiary
- Proteomics
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
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Affiliation(s)
- Gwladys I. Bertin
- Institut de Recherche pour le Développement (IRD), UMR216-Mère et enfant face aux infections tropicales, Paris, France
- PRES Paris Sorbonne Cité, Université Paris Descartes, Paris, France
| | - Thomas Lavstsen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - François Guillonneau
- PRES Paris Sorbonne Cité, Université Paris Descartes, Paris, France
- 3P5 proteomics facility, Université Paris Descartes, Paris, France
| | - Justin Doritchamou
- Institut de Recherche pour le Développement (IRD), UMR216-Mère et enfant face aux infections tropicales, Paris, France
- PRES Paris Sorbonne Cité, Université Paris Descartes, Paris, France
- Centre d’Étude et de Recherche sur le Paludisme Associé à la Grossesse et l′Enfance (CERPAGE), Cotonou, Bénin
| | - Christian W. Wang
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Jakob S. Jespersen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Sem Ezimegnon
- Centre d’Étude et de Recherche sur le Paludisme Associé à la Grossesse et l′Enfance (CERPAGE), Cotonou, Bénin
| | - Nadine Fievet
- Institut de Recherche pour le Développement (IRD), UMR216-Mère et enfant face aux infections tropicales, Paris, France
- PRES Paris Sorbonne Cité, Université Paris Descartes, Paris, France
- Centre d’Étude et de Recherche sur le Paludisme Associé à la Grossesse et l′Enfance (CERPAGE), Cotonou, Bénin
| | - Maroufou J. Alao
- Paediatric Department, Mother and child hospital (HOMEL), Cotonou, Bénin
| | - Francis Lalya
- Paediatric Department, Centre National Hospitalo-Universitaire (CNHU), Cotonou, Bénin
| | - Achille Massougbodji
- Centre d’Étude et de Recherche sur le Paludisme Associé à la Grossesse et l′Enfance (CERPAGE), Cotonou, Bénin
| | - Nicaise Tuikue Ndam
- Institut de Recherche pour le Développement (IRD), UMR216-Mère et enfant face aux infections tropicales, Paris, France
- PRES Paris Sorbonne Cité, Université Paris Descartes, Paris, France
- Centre d’Étude et de Recherche sur le Paludisme Associé à la Grossesse et l′Enfance (CERPAGE), Cotonou, Bénin
| | - Thor G. Theander
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Philippe Deloron
- Institut de Recherche pour le Développement (IRD), UMR216-Mère et enfant face aux infections tropicales, Paris, France
- PRES Paris Sorbonne Cité, Université Paris Descartes, Paris, France
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8
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Rovira-Vallbona E, Monteiro I, Bardají A, Serra-Casas E, Neafsey DE, Quelhas D, Valim C, Alonso P, Dobaño C, Ordi J, Menéndez C, Mayor A. VAR2CSA signatures of high Plasmodium falciparum parasitemia in the placenta. PLoS One 2013; 8:e69753. [PMID: 23936092 PMCID: PMC3723727 DOI: 10.1371/journal.pone.0069753] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/11/2013] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum infected erythrocytes (IE) accumulate in the placenta through the interaction between Duffy-binding like (DBL) domains of parasite-encoded ligand VAR2CSA and chondroitin sulphate-A (CSA) receptor. Polymorphisms in these domains, including DBL2X and DBL3X, may affect their antigenicity or CSA-binding affinity, eventually increasing parasitemia and its adverse effects on pregnancy outcomes. A total of 373 DBL2X and 328 DBL3X sequences were obtained from transcripts of 20 placental isolates infecting Mozambican women, resulting in 176 DBL2X and 191 DBL3X unique sequences at the protein level. Sequence alignments were divided in segments containing combinations of correlated polymorphisms and the association of segment sequences with placental parasite density was tested using Bonferroni corrected regression models, taking into consideration the weight of each sequence in the infection. Three DBL2X and three DBL3X segments contained signatures of high parasite density (P<0.003) that were highly prevalent in the parasite population (49-91%). Identified regions included a flexible loop that contributes to DBL3X-CSA interaction and two DBL3X motifs with evidence of positive natural selection. Limited antibody responses against signatures of high parasite density among malaria-exposed pregnant women could not explain the increased placental parasitemia. These results suggest that a higher binding efficiency to CSA rather than reduced antigenicity might provide a biological advantage to parasites with high parasite density signatures in VAR2CSA. Sequences contributing to high parasitemia may be critical for the functional characterization of VAR2CSA and the development of tools against placental malaria.
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MESH Headings
- Adolescent
- Amino Acid Sequence
- Antibodies, Protozoan/blood
- Antibodies, Protozoan/immunology
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/metabolism
- Binding Sites
- Chondroitin Sulfates/chemistry
- Chondroitin Sulfates/metabolism
- Erythrocytes/metabolism
- Erythrocytes/parasitology
- Female
- Humans
- Malaria, Falciparum/immunology
- Malaria, Falciparum/metabolism
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/pathology
- Molecular Docking Simulation
- Molecular Sequence Data
- Placenta/immunology
- Placenta/parasitology
- Placenta/pathology
- Plasmodium falciparum/chemistry
- Plasmodium falciparum/genetics
- Plasmodium falciparum/metabolism
- Pregnancy
- Pregnancy Complications, Parasitic/immunology
- Pregnancy Complications, Parasitic/metabolism
- Pregnancy Complications, Parasitic/parasitology
- Pregnancy Complications, Parasitic/pathology
- Protein Binding
- Protein Structure, Tertiary
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- Transcriptome
- Young Adult
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Affiliation(s)
- Eduard Rovira-Vallbona
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| | - Isadora Monteiro
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| | - Azucena Bardají
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Elisa Serra-Casas
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| | | | - Diana Quelhas
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Clarissa Valim
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Pedro Alonso
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Carlota Dobaño
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Jaume Ordi
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Department of Pathology, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Clara Menéndez
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Alfredo Mayor
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- * E-mail:
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9
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Mayor A, Kumar U, Bardají A, Gupta P, Jiménez A, Hamad A, Sigaúque B, Singh B, Quintó L, Kumar S, Gupta PK, Chauhan VS, Dobaño C, Alonso PL, Menéndez C, Chitnis CE. Improved Pregnancy Outcomes in Women Exposed to Malaria With High Antibody Levels Against Plasmodium falciparum. J Infect Dis 2013; 207:1664-74. [DOI: 10.1093/infdis/jit083] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Tutterrow YL, Salanti A, Avril M, Smith JD, Pagano IS, Ako S, Fogako J, Leke RGF, Taylor DW. High avidity antibodies to full-length VAR2CSA correlate with absence of placental malaria. PLoS One 2012; 7:e40049. [PMID: 22761948 PMCID: PMC3383675 DOI: 10.1371/journal.pone.0040049] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/31/2012] [Indexed: 11/29/2022] Open
Abstract
VAR2CSA mediates sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, increasing the risk of poor pregnancy outcomes. Naturally acquired antibodies (Ab) to placental parasites at delivery have been associated with improved pregnancy outcomes, but Ab levels and how early in pregnancy Ab must be present in order to eliminate placental parasites before delivery remains unknown. Antibodies to individual Duffy-binding like domains of VAR2CSA have been studied, but the domains lack many of the conformational epitopes present in full-length VAR2CSA (FV2). Thus, the purpose of this study was to describe the acquisition of Ab to FV2 in women residing in high and low transmission areas and determine how Ab levels during pregnancy correlate with clearance of placental parasites. Plasma samples collected monthly throughout pregnancy from pregnant women living in high and low transmission areas in Cameroon were evaluated for Ab to FV2 and the proportion of high avidity Ab (i.e., Ab that remain bound in the presence of 3M NH4SCN) was assessed. Ab levels and proportion of high avidity Ab were compared between women with placental malaria (PM+) and those without (PM−) at delivery. Results showed that PM− women had significantly higher Ab levels (p = 0.0047) and proportion of high avidity Ab (p = 0.0009) than PM+ women throughout pregnancy. Specifically, women with moderate to high Ab levels (>5,000 MFI) and those with ≥35% high avidity Ab at 5–6 months were found to have 2.3 (95% CI, 1.0–4.9) and 7.6-fold (p = 0.0013, 95% CI: 1.2–50.0) reduced risk of placental malaria, respectively. These data show that high levels of Ab to FV2, particularly those with high avidity for FV2, produced by mid-pregnancy are important in clearing parasites from the placenta. Both high Ab levels and proportion of high avidity Ab to FV2 may serve as correlates of protection for assessing immunity against placental malaria.
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Affiliation(s)
- Yeung Lo Tutterrow
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawai'i-Mānoa, Honolulu, Hawaii, United States of America
| | - Ali Salanti
- Department of International Health, Immunology and Microbiology, Centre for Medical Parasitology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Marion Avril
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Joseph D. Smith
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Ian S. Pagano
- Cancer Research Center, University of Hawaii-Mānoa, Honolulu, Hawaii, United States of America
| | - Simon Ako
- The Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Josephine Fogako
- The Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Rose G. F. Leke
- The Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Diane Wallace Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawai'i-Mānoa, Honolulu, Hawaii, United States of America
- * E-mail:
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11
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High levels of antibodies to multiple domains and strains of VAR2CSA correlate with the absence of placental malaria in Cameroonian women living in an area of high Plasmodium falciparum transmission. Infect Immun 2012; 80:1479-90. [PMID: 22331427 DOI: 10.1128/iai.00071-12] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Placental malaria, caused by sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, is associated with increased risk of maternal morbidity and poor birth outcomes. The parasite antigen VAR2CSA (variant surface antigen 2-chondroitin sulfate A) is expressed on infected erythrocytes and mediates binding to chondroitin sulfate A, initiating inflammation and disrupting homeostasis at the maternal-fetal interface. Although antibodies can prevent sequestration, it is unclear whether parasite clearance is due to antibodies to a single Duffy binding-like (DBL) domain or to an extensive repertoire of antibodies to multiple DBL domains and allelic variants. Accordingly, plasma samples collected longitudinally from pregnant women were screened for naturally acquired antibodies against an extensive panel of VAR2CSA proteins, including 2 to 3 allelic variants for each of 5 different DBL domains. Analyses were performed on plasma samples collected from 3 to 9 months of pregnancy from women living in areas in Cameroon with high and low malaria transmission. The results demonstrate that high antibody levels to multiple VAR2CSA domains, rather than a single domain, were associated with the absence of placental malaria when antibodies were present from early in the second trimester until term. Absence of placental malaria was associated with increasing antibody breadth to different DBL domains and allelic variants in multigravid women. Furthermore, the antibody responses of women in the lower-transmission site had both lower magnitude and lesser breadth than those in the high-transmission site. These data suggest that immunity to placental malaria results from high antibody levels to multiple VAR2CSA domains and allelic variants and that antibody breadth is influenced by malaria transmission intensity.
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12
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Menéndez C, Moorthy VS, Reed Z, Bardají A, Alonso P, Brown GV. Development of vaccines to prevent malaria in pregnant women: WHO MALVAC meeting report. Expert Rev Vaccines 2012; 10:1271-80. [PMID: 21919617 DOI: 10.1586/erv.11.95] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The major public health consequences of malaria in pregnancy have long been acknowledged. However, further information is still required for development and implementation of a malaria vaccine specifically directed to prevent malaria in pregnant women and improve maternal, fetal and infant outcomes. The WHO Malaria Vaccine Advisory Committee (MALVAC) provides guidance to the WHO on strategic priorities and research needs for development of vaccines to prevent malaria. Here we summarize the discussions and conclusions of a MALVAC scientific forum meeting on considerations in the development of vaccines to prevent malaria in pregnant women. This report includes brief summaries of what is known, and major knowledge gaps in disease burden estimation, pathogenesis and immunity, and the challenges with current preventive strategies for malaria in pregnancy. We conclude with the formulation of a conceptual framework for research and development for vaccines to prevent malaria in pregnant women.
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Affiliation(s)
- Clara Menéndez
- Barcelona Center for International Health Research (CRESIB), Hospital Clinic/Universitat de Barcelona, Barcelona, Spain
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13
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Parity and placental infection affect antibody responses against Plasmodium falciparum during pregnancy. Infect Immun 2011; 79:1654-9. [PMID: 21300778 DOI: 10.1128/iai.01000-10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Women are at higher risk of Plasmodium falciparum infection when pregnant. The decreasing risk of malaria with subsequent pregnancies is attributed to parity-dependent acquisition of antibodies against placental parasites expressing variant surface antigens, VAR2CSA, that mediate placental sequestration through adhesion to chondroitin sulfate A (CSA). However, modulation of immunity during pregnancy may also contribute to increase the risk of malaria. We compared antibody responses among 30 Mozambican primigravidae and 60 multigravidae at delivery, 40 men, and 40 children. IgG levels were measured against the surface antigens of erythrocytes infected with P. falciparum isolated from 12 pregnant women (4 placental and 8 peripheral blood isolates) and 26 nonpregnant hosts. We also measured IgG levels against merozoite recombinant antigens and total IgG. Placental P. falciparum infection was associated with increased levels of total IgG as well as IgG levels against merozoite antigens and parasite isolates from pregnant and nonpregnant hosts. We therefore stratified comparisons of antibody levels by placental infection. Compared to multigravidae, uninfected primigravidae had lower total IgG as well as lower levels of IgGs against peripheral blood isolates from both pregnant and nonpregnant hosts. These differences were not explained by use of bed nets, season at delivery, neighborhood of residence, or age. Compared to men, infected primigravidae had higher levels of IgGs against isolates from pregnant women and CSA-binding lines but not against other isolates, supporting the concept of a pregnancy-specific development of immunity to these parasite variants. Results of this study show that parity and placental infection can modulate immune responses during pregnancy against malaria parasites.
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14
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Persistence of Plasmodium falciparum parasites in infected pregnant Mozambican women after delivery. Infect Immun 2010; 79:298-304. [PMID: 21041485 DOI: 10.1128/iai.00814-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pregnant women are susceptible to Plasmodium falciparum parasites that sequester in the placenta. The massive accumulation of infected erythrocytes in the placenta has been suggested to trigger the deleterious effects of malaria in pregnant women and their offspring. The risk of malaria is also high during the postpartum period, although mechanisms underlying this susceptibility are not known. Here, we aimed to identify host factors contributing to the risk of postpartum infections and to determine the origin of postpartum parasites by comparing their genotypes with those present at the time of delivery. To address this, blood samples were collected at delivery (n = 402) and postpartum (n = 354) from Mozambican women enrolled in a trial of intermittent preventive treatment in pregnancy (IPTp). P. falciparum was detected by real-time quantitative PCR (qPCR), and the parasite merozoite surface protein 1 (msp-1) and msp-2 genes were genotyped. Fifty-seven out of 354 (16%) women were infected postpartum as assessed by qPCR, whereas prevalence by optical microscopy was only 4%. Risk of postpartum infection was lower in older women (odds ratio [OR] = 0.34, 95% confidence interval [CI] = 0.15 to 0.81) and higher in women with a placental infection at delivery (OR = 4.20, 95% CI = 2.19 to 8.08). Among 24 women with matched infections, 12 (50%) were infected postpartum with at least one parasite strain that was also present in their placentas. These results suggest that parasites infecting pregnant women persist after delivery and increase the risk of malaria during the postpartum period. Interventions that reduce malaria during pregnancy may translate into a lower risk of postpartum infection.
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Badaut C, Bertin G, Rustico T, Fievet N, Massougbodji A, Gaye A, Deloron P. Towards the rational design of a candidate vaccine against pregnancy associated malaria: conserved sequences of the DBL6epsilon domain of VAR2CSA. PLoS One 2010; 5:e11276. [PMID: 20585655 PMCID: PMC2890577 DOI: 10.1371/journal.pone.0011276] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 05/30/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Placental malaria is a disease linked to the sequestration of Plasmodium falciparum infected red blood cells (IRBC) in the placenta, leading to reduced materno-fetal exchanges and to local inflammation. One of the virulence factors of P. falciparum involved in cytoadherence to chondroitin sulfate A, its placental receptor, is the adhesive protein VAR2CSA. Its localisation on the surface of IRBC makes it accessible to the immune system. VAR2CSA contains six DBL domains. The DBL6epsilon domain is the most variable. High variability constitutes a means for the parasite to evade the host immune response. The DBL6epsilon domain could constitute a very attractive basis for a vaccine candidate but its reported variability necessitates, for antigenic characterisations, identifying and classifying commonalities across isolates. METHODOLOGY/PRINCIPAL FINDINGS Local alignment analysis of the DBL6epsilon domain had revealed that it is not as variable as previously described. Variability is concentrated in seven regions present on the surface of the DBL6epsilon domain. The main goal of our work is to classify and group variable sequences that will simplify further research to determine dominant epitopes. Firstly, variable sequences were grouped following their average percent pairwise identity (APPI). Groups comprising many variable sequences sharing low variability were found. Secondly, ELISA experiments following the IgG recognition of a recombinant DBL6epsilon domain, and of peptides mimicking its seven variable blocks, allowed to determine an APPI cut-off and to isolate groups represented by a single consensus sequence. CONCLUSIONS/SIGNIFICANCE A new sequence approach is used to compare variable regions in sequences that have extensive segmental gene relationship. Using this approach, the VAR2CSA DBL6 domain is composed of 7 variable blocks with limited polymorphism. Each variable block is composed of a limited number of consensus types. Based on peptide based ELISA, variable blocks with 85% or greater sequence identity are expected to be recognized equally well by antibody and can be considered the same consensus type. Therefore, the analysis of the antibody response against the classified small number of sequences should be helpful to determine epitopes.
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Affiliation(s)
- Cyril Badaut
- Mother and Child Faced with Tropical Infections Research Unit, Institut de Recherche pour le Développement, UMR216, Paris, France
- Université Paris Descartes, Paris, France
- * E-mail: (CB); (PD)
| | - Gwladys Bertin
- Mother and Child Faced with Tropical Infections Research Unit, Institut de Recherche pour le Développement, UMR216, Paris, France
- Université Paris Descartes, Paris, France
| | - Tatiana Rustico
- Mother and Child Faced with Tropical Infections Research Unit, Institut de Recherche pour le Développement, UMR216, Paris, France
| | - Nadine Fievet
- Mother and Child Faced with Tropical Infections Research Unit, Institut de Recherche pour le Développement, UMR216, Paris, France
| | - Achille Massougbodji
- Département de Zoologie et Génétique, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, Benin
| | - Alioune Gaye
- Centre de Santé Roi Baudoin de Guédiawaye, Dakar, Senegal
| | - Philippe Deloron
- Mother and Child Faced with Tropical Infections Research Unit, Institut de Recherche pour le Développement, UMR216, Paris, France
- Université Paris Descartes, Paris, France
- * E-mail: (CB); (PD)
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Niang M, Marrama L, Ekala MT, Alioune G, Tall A, Ndiaye JL, Sarr D, Dangou JM, Lehesran JY, Bouchier C, Mercereau-Puijalon O, Jambou R. Accumulation of CVIET Pfcrt allele of Plasmodium falciparum in placenta of pregnant women living in an urban area of Dakar, Senegal. J Antimicrob Chemother 2008; 62:921-8. [PMID: 18682531 DOI: 10.1093/jac/dkn299] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Chemoprophylaxis is recommended during pregnancy to reduce the risk of placental infection. However, in areas with increasing drug resistance, it can trigger selection of resistant parasites in the placenta and increase the frequency of placental malaria. The objective of this study was to analyse the selection of drug-resistant parasites in the placenta in an area where chloroquine was still recommended as prophylaxis. PATIENTS AND METHODS We analysed the polymorphism of parasites from matched placental and venous blood samples at the time of delivery from women in Dakar. Polymorphism of the isolates was studied using nested PCR typing of MSA1 and MSA2 genes, and full sequence of PfCRT exon 2. RESULTS Of 692 women recruited at delivery, 72 had placental malaria. Two Pfcrt exon 2 genotypes were found, and 86% of the placentas had monoallelelic CVIET infection compared with 39% that had peripheral blood infection. Mixed parasite populations of CVIET/CVMNK occurred in 53% of the peripheral blood samples but only in 7% of the infected placentas. This selection of CVIET in placenta was not related to a decreased polymorphism of the parasites, as a large diversity of MSA1 and MSA2 was found in both placenta and venous blood. This diversity confirms that a multiplicity of circulation isolates can occur at low parasite transmission. msp1 and msp2 genotyping revealed mostly distinct populations of parasites in venous and placental blood. CONCLUSIONS These data suggest that, even in low transmission areas, diverse parasite populations can accumulate in the placenta during pregnancy despite strong selection at the PfCRT locus due to chemoprophylaxis with chloroquine.
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Affiliation(s)
- Makhtar Niang
- Unité d'Immunologie, Institut Pasteur de Dakar, Sénégal
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