RESUMO
Haptoglobin (Hp) levels were investigated in relation to host genotype in a malaria-endemic area in Gabon. A cross-sectional study of 1-12-year-old children was conducted in the rainy season, a period of high malaria transmission, to examine this relationship. Variables that influenced Hp levels were Hp genotype, location, and age interacting with parasite density. At low parasite densities, there was a negative correlation between Hp levels and age. At higher densities, there was a positive correlation with age. This suggests that in the presence of greater parasite-induced hemolysis, older children are capable of increased production of Hp. Sickle cell trait and ABO blood group was not associated with Hp levels in this population.
Assuntos
Envelhecimento/sangue , Haptoglobinas/análise , Haptoglobinas/genética , Malária/sangue , Malária/epidemiologia , Parasitemia/sangue , Animais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Gabão/epidemiologia , Genótipo , Humanos , Lactente , Masculino , Plasmodium falciparum/isolamento & purificação , Plasmodium malariae/isolamento & purificação , Traço Falciforme/genética , Traço Falciforme/metabolismoRESUMO
INTRODUCTION: Placental malaria (PM) is a major public health problem that constitutes a significant health concern for the mother, and especially for the developing fetus and offspring. Current means of prevention have limitations, including a restricted window of intervention that excludes the first trimester of pregnancy, and the fact that very few drugs can be used for this purpose. The identification of the VAR2CSA antigen, specific to PM parasites, offers an excellent opportunity to develop a vaccine against this disease. Proof of concept of a first-generation vaccine is nearing completion, and two clinical trials are underway. AREAS COVERED: This review focuses on PM, which is mainly caused by Plasmodium falciparum. The review highlights recent advances and the key milestones that led to the identification of the optimal vaccine target within the large VAR2CSA protein. The paper also points out how future improvements can strengthen this process to achieve an effective vaccine in the field. EXPERT OPINION: The approach taken to develop a P. falciparum erythrocyte membrane protein 1-based vaccine to protect pregnant women is very promising in view of the current difficulties of achieving a sterilizing vaccine against malaria parasite. This approach could help us to control the deleterious effect of malaria infections that characterize severe clinical forms.