[Profiles of IgG responses against CSP, GLURP and LSA-3NR2 in urban malaria (Dakar): relations with haemoglobin levels and parasite densities].
Malaria remains a major health problem in sub- Saharan African countries despite substantial decreases in morbidity and mortality due to sustained control programs. Vaccines candidates were mainly tested in rural endemic setting; however increasing proportion of the population is living in urban area. Evaluation of the qualitative or quantitative immune responses to key targets of anti-Plasmodium immunity requires further investigation in urban area. In a cohort of 144 patients with mild malaria living in Dakar, we analyzed IgG responses against target antigens of P. falciparum: CSP, LSA-3NR2 and GLURP by ELISA. A mean age of 15 yrs (4-65 yrs) was found and patients were separated in 59 adults (<15yrs) and 85 children (≤15 yrs). Parasites densities (0,01-15%) did not differ between the two age groups. In contrast, haemoglobin levels appeared lower in children (4.5-16.6 g/dl) (p<0.01). For the immune results, the most recognized antigens were GLURP and CSP compared to LSA-3NR2. Levels of IgG against these antigens were significantly different between the two age groups and they were positively correlated (rho = 0.32; p<0.001). In addition, levels of IgG anti-GLURP were associated with low parasitemia (≤1%) and absence of anemia (≥11g/dl), particularly in adults (p<0.001). In a multiple regression analysis, no significant relationship was found between parasite densities and IgG responses against all the tested antigens. Our study shows the implication of IgG anti-GLURP in humoral immune response against the parasite. The present work contributes to determine IgG levels that can be used as relevant immunologic biomarkers in urban clinical malaria.
Service d'immunologie FMPO, Université Cheikh Anta Diop, Dakar, Sénégal. babacar.mbengue@ucad.edu.sn.|Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal. babacar.mbengue@ucad.edu.sn.
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Mbengue
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Kpodji
Service d'immunologie FMPO, Université Cheikh Anta Diop, Dakar, Sénégal.
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Sylla Niang
Unité d'immunologie, Institut Pasteur de Dakar, Dakar, Sénégal.
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ML
Varela
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Thiam
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Sow
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Ndiaye
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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M
Aidara
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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F
Thiam
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Ndiaye
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Diop
Département génie chimique et biologie appliquée, ESP, Université Cheikh Anta Diop, Dakar, Sénégal.
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Nguer
Unité d'immunologie, Institut Pasteur de Dakar, Dakar, Sénégal.
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Perraut
Unité d'immunogénétique, Institut Pasteur de Dakar, Dakar, Sénégal.
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Dièye
D000293:Adolescent; D000328:Adult; D000368:Aged; D000913:Antibodies, Protozoan / Q000032:analysis / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000097:blood; D017780:Malaria Vaccines / Q000276:immunology*; D016778:Malaria, Falciparum / Q000097:blood* / Q000276:immunology* / Q000469:parasitology*; D008297:Male; D008875:Middle Aged; D059208:Parasite Load; D018512:Parasitemia / Q000097:blood; D010963:Plasmodium falciparum / Q000254:growth & development / Q000276:immunology; D015800:Protozoan Proteins / Q000276:immunology; D014505:Urban Population; D055815:Young Adult
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D006454:Hemoglobins; D007074:Immunoglobulin G; D017780:Malaria Vaccines; D015800:Protozoan Proteins; C067302:liver stage-specific antigen, Plasmodium; C072492:glutamate-rich protein, Plasmodium
CSP; GLURP; Haemoglobin level; IgG; LSA-3NR2; P. falciparum; Parasitemia; Pikine; Senegal; Sub-Saharan Africa; Urban malaria