2023 |
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Journal Articles |
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Hamtandi Magloire Natama, Gemma Moncunill, Marta Vidal, Toussaint Rouamba, Ruth Aguilar, Rebeca Santano, Eduard Rovira-Vallbona, Alfons Jiménez, M. Athanase Somé, Hermann Sorgho, Innocent Valéa, Maminata Coulibaly-Traoré, Ross L. Coppel, David Cavanagh, Chetan E. Chitnis, James G. Beeson, Evelina Angov, Sheetij Dutta, Benoit Gamain, Luis Izquierdo, Petra F. Mens, Henk D. F. H. Schallig, Halidou Tinto, Anna Rosanas-Urgell, Carlota Dobaño Associations between prenatal malaria exposure, maternal antibodies at birth, and malaria susceptibility during the first year of life in Burkina Faso Journal Article In: Infection and immunity, vol. 91, iss. 10, pp. 290, 2023, ISSN: 1098-5522. Abstract | BibTeX | Tags: Antibodies, Antigens, Burkina Faso / epidemiology, Carlota Dobaño, Child, Cohort Studies, doi:10.1128/iai.00268-23, Falciparum*, Female, Gemma Moncunill, Hamtandi Magloire Natama, Humans, Immunoglobulin G, Infant, Malaria, Malaria* / epidemiology, Maternal Exposure, MEDLINE, National Center for Biotechnology Information, National Institutes of Health, National Library of Medicine, NCBI, Newborn, NIH, NLM, placenta, Plasmodium falciparum, PMC10580994, pmid:37754682, Pregnancy, Preschool, Protozoan, PubMed Abstract | Links: @article{Natama2023, In this study, we investigated how different categories of prenatal malaria exposure (PME) influence levels of maternal antibodies in cord blood samples and the subsequent risk of malaria in early childhood in a birth cohort study (N = 661) nested within the COSMIC clinical trial (NCT01941264) in Burkina Faso. Plasmodium falciparum infections during pregnancy and infants’ clinical malaria episodes detected during the first year of life were recorded. The levels of maternal IgG and IgG1-4 to 15 P. falciparum antigens were measured in cord blood by quantitative suspension array technology. Results showed a significant variation in the magnitude of maternal antibody levels in cord blood, depending on the PME category, with past placental malaria (PM) more frequently associated with significant increases of IgG and/or subclass levels across three groups of antigens defined as pre-erythrocytic, erythrocytic, and markers of PM, as compared to those from the cord of non-exposed control infants. High levels of antibodies to certain erythrocytic antigens (i.e., IgG to EBA140 and EBA175, IgG1 to EBA175 and MSP142, and IgG3 to EBA140 and MSP5) were independent predictors of protection from clinical malaria during the first year of life. By contrast, high levels of IgG, IgG1, and IgG2 to the VAR2CSA DBL1-2 and IgG4 to DBL3-4 were significantly associated with an increased risk of clinical malaria. These findings indicate that PME categories have different effects on the levels of maternal-derived antibodies to malaria antigens in children at birth, and this might drive heterogeneity to clinical malaria susceptibility in early childhood. | |||
Japhet Kabalu Tshiongo, Flory Luzolo, Melissa Kabena, Lise Kuseke, Moussa Djimde, Patrick Mitashi, Crispin Lumbala, Kassoum Kayentao, Sandra Menting, Petra F. Mens, Henk D. F. H. Schallig, Pascal Lutumba, Halidou Tinto, Hypolite Muhindo Mavoko, Vivi Maketa Performance of ultra-sensitive malaria rapid diagnostic test to detect Plasmodium falciparum infection in pregnant women in Kinshasa, the Democratic Republic of the Congo Journal Article In: Malaria journal, vol. 22, iss. 1, 2023, ISSN: 1475-2875. Abstract | BibTeX | Tags: Antigens, Democratic Republic of the Congo, Diagnostic Tests, doi:10.1186/s12936-023-04749-2, Falciparum* / epidemiology, Female, Flory Luzolo, Humans, Japhet Kabalu Tshiongo, Malaria, Malaria*, MEDLINE, National Center for Biotechnology Information, National Institutes of Health, National Library of Medicine, NCBI, NIH, NLM, Plasmodium falciparum, PMC10594769, pmid:37872634, Pregnancy, Pregnant Women, Protozoan, PubMed Abstract, Rapid diagnostic tests, Routine / methods, Sensitivity and Specificity, Vivi Maketa | Links: @article{nokey, Background: Low peripheral parasitaemia caused by sequestration of Plasmodium falciparum in the placenta hampers the diagnosis of malaria in pregnant women, leading to microscopy or conventional rapid diagnostic tests (RDTs) false-negative results. Although mainly asymptomatic, maternal malaria remains harmful to pregnant women and their offspring in endemic settings and must be adequately diagnosed. Ultra-sensitive RDTs (uRDTs) are thought to be more sensitive than RDTs, and their diagnostic performance was assessed in the current study in pregnant women living in Kinshasa, a stable malaria transmission area in the Democratic Republic of the Congo. Methods: To assess and compare the diagnostic performances of both RDTs and uRDTs, 497 peripheral blood samples were tested using microscopy and quantitative polymerase chain reaction (qPCR) as the index and the reference tests, respectively. The agreement between the different diagnostic tests assessed was estimated by Cohen's Kappa test. Results: The median parasite density by qPCR was 292 p/μL of blood [IQR (49.7–1137)]. Using qPCR as the reference diagnostic test, the sensitivities of microscopy, RDT and uRDT were respectively [55.7% (95% CI 47.6–63.6)], [81.7% (95%CI 74.7–87.3)] and [88% (95% CI 81.9–92.6)]. The specificities of the tests were calculated at 98.5% (95% CI 96.6–99.5), 95.2% (95% CI 92.5–97.2) and 94.4% (95% CI 91.4–96.6) for microscopy, RDT and uRDT, respectively. The agreement between qPCR and uRDT was almost perfect (Kappa = 0.82). For parasite density (qPCR) below 100 p/µL, the sensitivity of RDT was 62% (95% CI 47.1–75.3) compared to 68% (95% CI 53.3–80.4) for uRDT. Between 100 and 200 p/µL, the sensitivity of RDT was higher, but still lower compared to uRDT: 89.4% (95% CI 66.8–98.7) for RDT versus 100% (95% CI 82.3–100) for uRDT. In both cases, microscopy was lower, with 20% (95% CI 10–33.7) and 47.3% (95% CI 24.4–71.1) respectively. Conclusions: uRDT has the potential to improve malaria management in pregnant women as it has been found to be slightly more sensitive than RDT in the detection of malaria in pregnant women but the difference was not significant. Microscopy has a more limited value for the diagnosis of malaria during the pregnancy, because of its lower sensitivity. | |||
2022 |
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Journal Articles |
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![]() | Dídac Macià, Joseph J. Campo, Gemma Moncunill, Chenjerai Jairoce, Augusto J. Nhabomba, Maximilian Mpina, Hermann Sorgho, David Dosoo, Ousmane Traore, Kwadwo Asamoah Kusi, Nana Aba Williams, Amit Oberai, Arlo Randall, Hèctor Sanz, Clarissa Valim, Kwaku Poku Asante, Seth Owusu-Agyei, Halidou Tinto, Selidji Todagbe Agnandji, Simon Kariuki, Ben Gyan, Claudia Daubenberger, Benjamin Mordmüller, Paula Petrone, Carlota Dobaño Strong off-target antibody reactivity to malarial antigens induced by RTS,S/AS01E vaccination is associated with protection. Journal Article In: JCI insight, vol. 7, iss. 10, 2022, ISSN: 2379-3708. Abstract | BibTeX | Tags: *Adaptive immunity, *Antigen, *Epidemiology, *Immunology, *Infectious disease, *Malaria, *Malaria Vaccines, *Malaria/prevention & control, Antibodies, Antigens, Child, Falciparum/prevention & control, Humans, Immunoglobulin G, Infant, Protozoan, Vaccination | Links: @article{nokey, The RTS,S/AS01E vaccine targets the circumsporozoite protein (CSP) of the Plasmodium falciparum (P. falciparum) parasite. Protein microarrays were used to measure levels of IgG against 1000 P. falciparum antigens in 2138 infants (age 6-12 weeks) and children (age 5-17 months) from 6 African sites of the phase III trial, sampled before and at 4 longitudinal visits after vaccination. One month postvaccination, IgG responses to 17% of all probed antigens showed differences between RTS,S/AS01E and comparator vaccination groups, whereas no prevaccination differences were found. A small subset of antigens presented IgG levels reaching 4- to 8-fold increases in the RTS,S/AS01E group, comparable in magnitude to anti-CSP IgG levels (~11-fold increase). They were strongly cross-correlated and correlated with anti-CSP levels, waning similarly over time and reincreasing with the booster dose. Such an intriguing phenomenon may be due to cross-reactivity of anti-CSP antibodies with these antigens. RTS,S/AS01E vaccinees with strong off-target IgG responses had an estimated lower clinical malaria incidence after adjusting for age group, site, and postvaccination anti-CSP levels. RTS,S/AS01E-induced IgG may bind strongly not only to CSP, but also to unrelated malaria antigens, and this seems to either confer, or at least be a marker of, increased protection from clinical malaria. |
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