ABSTRACT
Interleukin-21 (IL-21) is a newly described, typical, four-helix cytokine showing significant homology with IL-2, IL-4 and IL-15. It regulates IgG1 production and co-operates with IL-4 in the production of multiple antibody classes in vivo. IgG1 and IgG3 are critically involved in the development of clinical immunity to Plasmodium falciparum malaria. However, the mechanisms driving class-switch recombination towards these specific isotypes remain to be elucidated. Seventy-three children with P. falciparum-positive, thick blood smears were recruited from the pediatric wards of the Albert Schweitzer Hospital and the General Hospital in Lambaréné. Children were grouped into two categories according to age: group A (1 to 5 years old) and group B (6 to 16 years old). Patients with severe (severe anemia and/or hyperparasitemia) and mild malaria were enrolled. Prevalence and level of IL-21, total IgG and subclass (IgG1, IgG2, IgG3 and IgG4) titers were determined in plasma by enzyme-linked immunosorbent assay (ELISA). Plasma IL-21 levels correlated with IgG1 and IgG3 levels. Additionally, plasma IL-21 levels correlated with hemoglobin levels in younger children and with parasite density. Here we describe the relationship between IL-21 and antibodies for erythrocyte-binding antigen-175 (EBA-175) peptide 4, a malaria vaccine candidate in Gabonese children with acute falciparum malaria. This study provides new insights into the field of malaria.
Subject(s)
Antigens, Protozoan/chemistry , Gene Expression Regulation , Immunoglobulin G/chemistry , Interleukins/biosynthesis , Malaria, Falciparum/blood , Malaria, Falciparum/parasitology , Plasmodium falciparum/metabolism , Protozoan Proteins/chemistry , Adolescent , Animals , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Gabon , Humans , Infant , Interleukins/physiology , Malaria, Falciparum/immunologyABSTRACT
Fosmidomycin-clindamycin therapy given every 12 h for 3 days was compared with a standard single oral dose of sulfadoxine-pyrimethamine. The two treatments showed comparably good tolerabilities and had an identical high degree of efficacy of 94% in a randomized trial carried out with 105 Gabonese children aged 3 to 14 years with uncomplicated malaria. These antimalarials merit further clinical exploration.
