Western blot diagnosis of vivax malaria with multiple stage-specific antigens of the parasite.
Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), merozoite surface protein (MSP-1), apical merozoite antigen (AMA-1), serine repeat antigen (SERA), and exported antigen (EXP-1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using 5 antigens (91.9%) rather than using each antigen solely (55.6-80%), a combination of 2 (76.3-87.5%), 3 (85.6-90.6%), or 4 antigens (89.4-91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.
Son
E S
ES
Department of Parasitology and Catholic Institute of Parasitic Diseases, Catholic University of Korea, Seoul 137-701, Korea.
Kim
T S
TS
Nam
H W
HW
D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D006801:Humans; D008018:Life Cycle Stages / Q000276:immunology; D016780:Malaria, Vivax / Q000175:diagnosis*; D008403:Mass Screening; D010966:Plasmodium vivax / Q000276:immunology*; D011994:Recombinant Proteins / Q000097:blood; D012698:Serologic Tests / Q000379:methods
D000953:Antigens, Protozoan; D015415:Biomarkers; D011994:Recombinant Proteins