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Updated: Aug 5, 2026
14:10
Protocol for Plasmodium falciparum Infections in Mosquitoes and Infection Phenotype Determination
Published on: July 4, 2007
Antigenic disparity of Plasmodium vivax causing initial symptoms and causing relapse
S Khusmith1, S Tharavanij, D Bunnag
1Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Summary
Relapse infections in Plasmodium vivax malaria show antigenic differences in some patients. Monoclonal antibodies revealed altered parasite antigens in relapse strains, impacting treatment strategies.
Area of Science:
- Malariology
- Immunology
- Infectious Diseases
Background:
- Relapse infections are a significant challenge in treating Plasmodium vivax malaria.
- Understanding the antigenic nature of relapse parasites is crucial for effective control.
Purpose of the Study:
- To investigate the antigenic differences between initial and relapse Plasmodium vivax parasite strains.
- To analyze antibody recognition of parasite antigens in patients experiencing malaria relapse.
Main Methods:
- Indirect fluorescent antibody test (IFA) using 58 monoclonal antibodies (MAbs) against erythrocytic stages of P. vivax.
- Western immunoblotting to detect antibody responses to parasite antigens in patient sera.
Main Results:
- Three out of five relapse cases (R3, R4, R5) showed similar IFA reactivity between initial and relapse strains.
- Two cases (R1, R2) exhibited distinct IFA reactivity patterns, with altered antigen recognition by antibodies.
- Western blot analysis confirmed significant molecular alterations in parasite antigens recognized by antibodies in cases R1 and R2.
Conclusions:
- Antigenic variation occurs in Plasmodium vivax relapse infections in some individuals.
- These antigenic disparities may influence the efficacy of malaria treatments and control measures.
- Further research is needed to elucidate the mechanisms and implications of P. vivax antigenic variation during relapse.
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