Author/Authors :
Iriemenam, Nnaemeka C. University of Lagos - College of Medicine - ôTropical Diseases Research Laboratory, Department of Medical Microbiology Parasitology, Nigeria , Iriemenam, Nnaemeka C. Stockholm University - The Wenner-Gren Institute - Department of Immunology, Sweden , Okafor, Christian M. F. Stockholm University - Wenner-Gren Institute - Department of Immunology, Sweden , Okafor, Christian M. F. University of Ibadan - Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, Nigeria , Okafor, Christian M. F. Seattle Biomedical Research Institute, USA , Balogun, Halima A. Stockholm University - Wenner-Gren Institute - Department of Immunology, Sweden , Ayede, Idowu Oni Memorial Children’s Hospital, Nigeria , Omosun, Yusuf University of Ibadan - Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, Nigeria , Omosun, Yusuf Bells University of Technology - Department of Biotechnology, Nigeria , Persson, Jan Olov Stockholm University, Sweden , Hagstedt, Margareta Stockholm University - Wenner-Gren Institute - Department of Immunology, Sweden , Anumudu, Chiaka I. University of Ibadan - Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, Nigeria , Nwuba, Roseangela I. University of Ibadan - Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, Nigeria , Blomberg, Marita Troye Stockholm University - Wenner-Gren Institute - Department of Immunology, Sweden , Berzins, Klavs Stockholm University - Wenner-Gren Institute - Department of Immunology, Sweden
Abstract :
Background: The ability of the host immune system to efficiently clear Plasmodium falciparum parasites during a malaria infection depends on the type of immune response mounted by the host. Study design: In a cross-sectional study, we investigated the cellular-and antibody responses in individuals with P. falciparum infection, in an attempt to identify immunological signs indicative of the development of natural immunity against malaria in Ibadan, Nigeria. Levels of IL-10, IL-12(p70), IFN-γ, and IgM, IgG and IgG1-4 subclasses in the serum of 36 symptomatic children with microscopically confirmed malaria parasitaemia and 54 asymptomatic controls were analysed by ELISA. Results: IFN-γ and IL-10 were significantly higher in the symptomatic children (p=0.009, p=0.025 respectively) than in the asymptomatic controls but no differences were seen for IL-12(p70). Estimated higher ratios of IFN-γ/IL-10 and IFN-γ/IL-12 were also observed in the symptomatic children while the asymptomatic controls had higher IL-12/IL-10 ratio. The mean concentration levels of anti-P. falciparum IgG1, IgG2, IgG3 antibodies were statistically significantly higher in the individuals 5 years of age than 5 years while anti-P. falciparum IgG3 antibodies were notably low in 5 years category. Children 5 years had higher IgM antibodies than IgG and the expression of IgG subclasses increased with age. Conclusion: Taken together, malaria infection is on a delicate balance of pro- and anti-inflammatory cytokines. The higher levels of IFN-γ seen in the symptomatic children ( 6months) may be instrumental in immune-protection against malaria by limiting parasite replication. The observed variations in immunoglobulin subclass levels were age-dependent and exposure-related.
