Gora Diop

Analyses des réponses IgG dirigées contre des antigènes candidats vaccins dans le paludisme urbain non aggravé à Dakar (Sénégal) : variations suivant l’âge et les densités parasitaires

Malaria remains a major problem in African countries despite substantial decreases in morbidity and mortality due to sustained control programs. Studies for the evaluation of qualitative or quantitative Ab responses to key targets of anti-plasmodium immunity were mostly done in rural endemic setting compared to urban area. In a cohort of 200 patients with mild malaria and living in Dakar, we analyze total and subclasses IgG responses to a panel of P. falciparum blood stage antigens: MSP1p19, MSP3, EB200, GST-5 and R23. A mean age of 15 yrs (4 to 56 yrs) and parasitemia between 0.1 to 17% were found. Levels of IgG anti-MSP3 were higher in patients with low parasitemia (≤1%) and appear negatively correlated to parasite densities (Rho =. 0.54; p= 0.021). This correlation is more significant in children (≤ 15 yrs). In addition, an increase of IgG responses against MSP1p19 is highly observed in adults having a parasitemia less than 1%. In those patients, we find that IgG1 subclasses were predominant (p <0.01). Our study shows an association between Ab responses and parasitemia. This association is dependant to IgG anti-MSP3 in children and IgG anti-MSP1p19 in adults living in urban area.

[IgG responses to candidate malaria vaccine antigens in the urban area of Dakar (Senegal): evolution according to age and parasitemia in patients with mild symptoms].

Malaria remains a major problem in African countries despite substantial decreases in morbidity and mortality due to sustained control programs. Studies for the evaluation of qualitative or quantitative Ab responses to key targets of anti-plasmodium immunity were mostly done in rural endemic setting compared to urban area. In a cohort of 200 patients with mild malaria and living in Dakar, we analyze total and subclasses IgG responses to a panel of P. falciparum blood stage antigens: MSP1p19, MSP3, EB200, GST-5 and R23. A mean age of 15 yrs (4 to 56 yrs) and parasitemia between 0.1 to 17% were found. Levels of IgG anti-MSP3 were higher in patients with low parasitemia (≤1%) and appear negatively correlated to parasite densities (Rho =. 0.54; p= 0.021). This correlation is more significant in children (≤ 15 yrs). In addition, an increase of IgG responses against MSP1p19 is highly observed in adults having a parasitemia less than 1%. In those patients, we find that IgG1 subclasses were predominant (p <0.01). Our study shows an association between Ab responses and parasitemia. This association is dependant to IgG anti-MSP3 in children and IgG anti-MSP1p19 in adults living in urban area.

Profils des réponses IgG dirigées contre CSP, GLURP et LSA-3NR2 dans le paludisme urbain à Dakar : influence sur l’hémoglobinémie et les parasitémies circulantes

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.

[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.

Profils des réponses IgG dirigées contre CSP, GLURP et LSA-3NR2 dans le paludisme urbain à Dakar : influence sur l’hémoglobinémie et les parasitémies circulantes@@@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.

Analyses des réponses IgG dirigées contre des antigènes candidats vaccins dans le paludisme urbain non aggravé à Dakar (Sénégal) : variations suivant l'âge et les densités parasitaires IgG responses to candidate malaria vaccine antigens in the urban area of Dakar (Senegal): evolution according to age and parasitemia in patients with mild symptoms

Malaria remains a major problem in African countries despite substantial decreases in morbidity and mortality due to sustained control programs. Studies for the evaluation of qualitative or quantitative Ab responses to key targets of anti-plasmodium immunity were mostly done in rural endemic setting compared to urban area. In a cohort of 200 patients with mild malaria and living in Dakar, we analyze total and subclasses IgG responses to a panel of P. falciparum blood stage antigens: MSP1p19, MSP3, EB200, GST-5 and R23. A mean age of 15 yrs (4 to 56 yrs) and parasitemia between 0.1 to 17% were found. Levels of IgG anti-MSP3 were higher in patients with low parasitemia (≤1%) and appear negatively correlated to parasite densities (Rho =. 0.54; p= 0.021). This correlation is more significant in children (≤ 15 yrs). In addition, an increase of IgG responses against MSP1p19 is highly observed in adults having a parasitemia less than 1%. In those patients, we find that IgG1 subclasses were predominant (p <0.01). Our study shows an association between Ab responses and parasitemia. This association is dependant to IgG anti-MSP3 in children and IgG anti-MSP1p19 in adults living in urban area.

Étude du codon 72 du gène p53 dans la prédisposition au cancer du col de l’utérus au SénégalStudy of codon 72 of p53 gene as a risk-factor in cervical cancer in Senegal

Beside human papilloma virus infection, several genetic factors have been involved in susceptibility to cervical cancer. The arginine allele at codon 72 in p53 tumor suppressor gene has been reported to be a risk-factor in different ethnic groups. Our aim was to study this polymorphism as a risk-factor in Senegal. We conducted a case-control association study by recruiting 30 patients with cervical cancer clinically followed up in the Curie Institute in Dakar, and 93 healthy female controls without diagnosed cervical cancer. For each individual, DNA was extracted from whole blood. The codon 72 polymorphism was genotyped by PCR-RFLP. We did not find any association between the arginine allele and susceptibility to cervical cancer in our population (P = 0.354). Moreover, any correlation between the arginine allele and histological lesions was observed. Even if we did not find any correlation between the arginine allele and susceptibility to cervical cancer, p53 as a tumor suppressor gene remains a good genetic marker in tumours biology.