ABSTRACT
Background: Some MSP-1 19 specific antibodies that inhibit merozoite invasion also inhibit the secondary processing of MSP-1. However the binding of these inhibitory antibodies can be blocked by another group of antibodies; called blocking antibodies; which recognize adjacent or overlapping epitopes; but themselves have no effect on either MSP-1 processing or merozoite invasion. These antibodies have been reported to be present in individuals living in a malaria endemic area. Methods: Blood samples were obtained from children shown to have processing inhibitory; blocking; and neutral antibodies in a previous study. Enzyme linked immunosorbent assay (ELISA); was used to determine the total IgG; IgM and IgG subtypes.Results: There was a significant difference in anti-MSP-1 19 IgG; while there was no significant difference in the anti-MSP-1 19 IgM. Only anti MSP-1 19 IgG1; amongst the IgG subtypes was significantly different between the groups. Conclusion: This study shows that antibodies against MSP-1 are different not only in specificity and function but also in the amount of total IgG and IgG subtype produced
Subject(s)
Plasmodium falciparumABSTRACT
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-a; 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-a 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-a/IL-10 and IFN-a/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-a 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
Subject(s)
Anemia , Cytokines , Malaria , Plasmodium falciparumABSTRACT
Background: Effective control and management of severe malaria cases depends on a clear understanding of the local epidemiological factors and specific clinical manifesta- tions of the disease in the different endemic regions. Objectives: To determine the prevalence of severe malaria and epidemiological factors that affect the development of malaria anaemia. Methods: A cross-sectional survey was carried out among children below 5 years of age; at the Adeoyo State Maternity Hospital;Ibadan; Nigeria. Question-naires and case histories were taken from patients clinically diagnosed of malaria.Thus; 372 volunteers wererecruited into the study from the 3131 paediatric cases that reported over the10-week period to the out-patient department (OPD) ofthe hospital. 229 (61.6) of the recruited volunteers presented with fever (37.5 oC) at consultation.These had malaria parasite andPCV tests done. Results: Clinical diagnosis was confirmed microscopically in 78(290/372) for Plasmodium infection using thick film slides. Anaemia (PCV 28) prevalence was 28.2. Factors that contributed to the rapid progression of uncomplicated malaria to severestatus included: age of the child; level of parasitaemia; careless response and attitude of parents or guardians to fever in the children;parents' preoccupation with their jobs or other healthy children and unwillingness to use available health facilities. Conclusion: The study underscores the need for community involved partnership for malaria control especially through healtheducation for the home manage- ment of malaria; espeically among those experiencing some form of inequity in access to healthcare