Natural acquired anti- Plasmodium falciparum IgG antibody responses in Thai population

Abstract

Immunity to malaria has a major role in controlling the disease and its pathogenesis. Naturally acquired antibodies play a crucial role in developing immunity to malaria. Over the past two decades, anti-Plasmodium falciparum antibody prevalence to different malaria candidate antigens has been conducted in sera from individuals living in Thailand where malaria is endemic. They were village residents, occupational exposed soldiers, and patients with severe and uncomplicated malaria. Partial seroactivity was observed for anti-immunoglobulin (Ig) G antibodies to ring-infected erythrocyte surface antigens (erythrocyte membrane immunofluorescence [EMIF] whole parasite), Pf332, Pf155/Ring infected erythrocyte surface antigens (RESA), and the repeat region of the circumsporozoite (CS) protein (R32tet32). Prospective studies assessed only the anti- R32tet32 IgG antibody, unable to prevent malaria. Interestingly, all village residents, all occupational exposed soldiers, and all of those with acute falciparum malaria had IgG antibody responses to a late blood stage malaria antigen (whole). Furthermore, significant lowered levels of this antibody were seen in the patients who died, compared to those who recovered. Similar to whole sporozoite IgG antibody responses, significant lowered levels of sporozoite antibodies were observed in cerebral malaria compared to those with acute uncomplicated malaria. The exploration of naturally acquired anti-P.falciparum antibody prevalence, and its relation to the past's morbidity and mortality, may provide clue into malaria control strategies, especially vaccination. © 2012 Nova Science Publishers, Inc. All rights reserved.