Total Immunoglobulin G and IgG1 Subclass Levels Specific for the MSP-1 19 of Plasmodium falciparum are Different in Individuals with either Processing-Inhibitory; Blocking or Neutral Antibodies

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