title: A recombinant Plasmodium vivax apical membrane antigen-1 to detect human infection in Iran.
abstract: In Iran, Plasmodium vivax is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant P. vivax apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant His-tagged protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-P. vivax antibodies in the field was compared to light microscopy on 84 confirmed P. vivax patients and compared to 84 non-P. vivax infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with P. vivax infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.
authors.affiliation: Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Afsaneh Motevalli
authors.initials: AM
authors.lastname: Haghi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Khoramizade
authors.forename: Mehdi
authors.initials: M
authors.lastname: Nateghpour
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mohebali
authors.forename: Gholam Hossein
authors.initials: GH
authors.lastname: Edrissian
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Eshraghian
authors.forename: Zargham
authors.initials: Z
authors.lastname: Sepehrizadeh
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D000953:Antigens, Protozoan / Q000097:blood* / Q000235:genetics / Q000276:immunology; D003955:Diagnostic Tests, Routine / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D007492:Iran; D016780:Malaria, Vivax / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology*; D008297:Male; D008565:Membrane Proteins / Q000097:blood / Q000235:genetics / Q000276:immunology; D010966:Plasmodium vivax / Q000302:isolation & purification / Q000502:physiology*; D015800:Protozoan Proteins / Q000097:blood / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D008565:Membrane Proteins; D015800:Protozoan Proteins; C090077:apical membrane antigen I, Plasmodium